• Sign in to Neowin Faster!

    Create an account on Neowin to contribute and support the site.

Sign in to follow this  

Universe News (miscellaneous articles)

Recommended Posts

Draggendrop    5,747

Excellent choice Mirumur, I remember this one, due to Carl Sagan beside the Voyager. Does a great job leading up to the ultra deep field image. Thanks for sharing.

 

and some news.....

 

Runaway Stars Leave Infrared Waves in Space

 

oopia20062.thumb.jpg.8569dc2fea48a891e0d

Stellar bow shocks    NASA

 

Quote

Astronomers are finding dozens of the fastest stars in our galaxy with the help of images from NASA's Spitzer Space Telescope and Wide-field Infrared Survey Explorer, or WISE.

 

 

When some speedy, massive stars plow through space, they can cause material to stack up in front of them in the same way that water piles up ahead of a ship. Called bow shocks, these dramatic arc-shaped features in space are leading researchers to uncover massive, so-called runaway stars.

"Some stars get the boot when their companion star explodes in a supernova, and others can get kicked out of crowded star clusters," said astronomer William Chick from the University of Wyoming in Laramie, who presented his team's new results at the American Astronomical Society meeting in Kissimmee, Florida. "The gravitational boost increases a star's speed relative to other stars."

Our own Sun is strolling through our Milky Way galaxy at a moderate pace. It is not clear whether our Sun creates a bow shock. By comparison, a massive star with a stunning bow shock, called Zeta Ophiuchi (or Zeta Oph), is traveling around the galaxy faster than our Sun, at 54,000 mph (24 kilometers per second) relative to its surroundings. Zeta Oph's giant bow shock can be seen in the accompanying image from the WISE mission.

Both the speed of stars moving through space and their mass contribute to the size and shapes of bow shocks. The more massive a star, the more material it sheds in high-speed winds. Zeta Oph, which is about 20 times as massive as our Sun, has supersonic winds that slam into the material in front of it.

The result is a pile-up of material that glows. The arc-shaped material heats up and shines with infrared light. That infrared light is assigned the color red in the many pictures of bow shocks captured by Spitzer and WISE.

Chick and his team turned to archival infrared data from Spitzer and WISE to identify new bow shocks, including more distant ones that are harder to find. Their initial search turned up more than 200 images of fuzzy red arcs. They then used the Wyoming Infrared Observatory, near Laramie, to follow up on 80 of these candidates and identify the sources behind the suspected bow shocks. Most turned out to be massive stars.

The findings suggest that many of the bow shocks are the result of speedy runaways that were given a gravitational kick by other stars. However, in a few cases, the arc-shaped features could turn out to be something else, such as dust from stars and birth clouds of newborn stars. The team plans more observations to confirm the presence of bow shocks.

"We are using the bow shocks to find massive and/or runaway stars," said astronomer Henry "Chip" Kobulnicky, also from the University of Wyoming. "The bow shocks are new laboratories for studying massive stars and answering questions about the fate and evolution of these stars."

Another group of researchers, led by Cintia Peri of the Argentine Institute of Radio Astronomy, is also using Spitzer and WISE data to find new bow shocks in space. Only instead of searching for the arcs at the onset, they start by hunting down known speedy stars, and then they scan them for bow shocks.

"WISE and Spitzer have given us the best images of bow shocks so far," said Peri. "In many cases, bow shocks that looked very diffuse before, can now be resolved, and, moreover, we can see some new details of the structures."

Some of the first bow shocks from runaway stars were identified in the 1980s by David Van Buren of NASA's Jet Propulsion Laboratory in Pasadena, California. He and his colleagues found them using infrared data from the Infrared Astronomical Satellite (IRAS), a predecessor to WISE that scanned the whole infrared sky in 1983.

Kobulnicky and Chick belong to a larger team of researchers and students studying bow shocks and massive stars, including Matt Povich from the California State Polytechnic University, Pomona. The National Science Foundation funds their research.

Images from Spitzer, WISE and IRAS are archived at the NASA Infrared Science Archive housed at the Infrared Processing and Analysis Center at California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

Bow shock images and more information about Spitzer:
http://www.nasa.gov/spitzer
http://spitzer.caltech.edu

http://spaceref.com/astronomy/runaway-stars-leave-infrared-waves-in-space.html

 

---------------------------------------

 

Visible Light from a Black Hole Spotted by Telescope, a First

 

Quote

For the first time, astronomers have seen dim flickers of visible light from near a black hole, researchers with an international science team said. In fact, the light could be visible to anyone with a moderate-size telescope.

 

These dramatically variable fluctuations of light are yielding insights onto the complex ways in which matter can swirl into black holes, scientists added. The researchers also released a video of the black hole's light seen by a telescope. In a statement, they added that such light from an active black hole could be spotted by an observer with a 20-cm telescope.

 

black-hole-naked-eye.thumb.jpg.f7e2d527e

This image still from a video by scientists studying the black hole V404 Cygni located about 7,800 light-years from Earth shows visible light that could be viewable by stargazers with a medium-size telescope. 
Credit: Michael Richmond/Rochester Institute Of Technology

 

Quote

Anything falling into black holes cannot escape, not even light, earning black holes their name. However, as disks of gas and dust fall or accrete onto black holes — say, as black holes rip apart nearby stars — friction within these accretion disks can superheat them to 18 million degrees Fahrenheit (10 million degrees Celsius) or more, making them glow extraordinarily brightly. 

 

Scientists discovered accreting black holes in the Milky Way more than 40 years ago. Previous research suggested that the accretion disks of black holes can have dramatic effects on galaxies. For instance, streams of plasma known as relativistic jets that spew out from accreting black holes at near the speed of light can travel across an entire galaxy, potentially shaping its evolution. However, much remains unknown about how accretion works, since matter can behave in very complex ways as it spirals into black holes, said study lead author Mariko Kimura, an astronomer at Kyoto University in Japan, and her colleagues.

 

To learn more about the mysterious process of accretion, researchers in the new study analyzed V404 Cygni, a binary system composed of a black hole about nine times the mass of the sun and a companion star slightly less massive than the sun. Located about 7,800 light-years away from Earth in the constellation Cygnus, the swan, V404 Cygni possesses one of the black holes closest to Earth.

 

After 26 years during which the system was dormant, astronomers detected an outburst of X-rays from V404 Cygni in 2015 that lasted for about two weeks. This activity from the accretion disk of V404 Cygni's black hole briefly made it one of the brightest sources of X-rays seen in the universe.

 

Following this outburst, the researchers detected flickering visible light from V404 Cygni, whose fluctuations varied over timescales of 100 seconds to 150 minutes. Normally, astronomers monitor black holes by looking for X-rays or gamma-rays.

 

"We find that activity in the vicinity of a black hole can be observed in optical light at low luminosity for the first time," Kimura told Space.com. "These findings suggest that we can study physical phenomena that occur in the vicinity of the black hole using moderate optical telescopes without high-spec X-ray or gamma-ray telescopes."

 

Similar variable flickering was seen in the X-ray emissions from another black hole system, GRS 1915+105, located about 35,900 light-years away from Earth in the constellation Aquila, the eagle. GRS 1915+105 experiences high levels of accretion. As such, researchers previously suggested the system's variable flickering was due to instabilities that can occur in accretion disks when they get very massive.

 

However, the accretion rates at V404 Cygni are at least 10 times lower than those seen at other black hole systems that have similar oscillations. This suggests that high accretion rates are not the main factor behind this variable flickering, the researchers said.

 

Instead, the scientists noted that in both V404 Cygni and GRS 1915+105, the black holes and their companion stars are relatively far apart, which permits a large accretion disk to form. In such large disks, matter from the outer disk might not flow in a steady manner to the inner disk near the black hole, the researchers said. As such, the researchers suggest that accretion onto these black holes can become unstable and fluctuate wildly. This sporadic activity, they said, could then explain the oscillating patterns of light from these black holes.

 

The scientists said they hope that worldwide coordination will permit future research to better understand the nature of these extreme events.

 

"Thanks to international cooperation, we could get extensive optical observational data in our research with 35 telescopes at 26 locations," Kimura said. "We would like more people to join in optical observations of black-hole binaries."

 

Kimura and her colleagues detailed their findings in the Jan. 7 issue of the journal Nature.

http://www.space.com/31532-black-hole-visible-light-telescope-discovery.html

 

:)

  • Like 3

Share this post


Link to post
Share on other sites
Draggendrop    5,747

Most distant massive galaxy cluster identified

 

galaxy-cluster-idcs-j14265-3508-hubble-k

To get a more precise estimate of the galaxy cluster's mass, Michael McDonald and his colleagues used data from several of NASA's Great Observatories: the Hubble Space Telescope, the Keck Observatory, and the Chandra X-ray Observatory. Image courtesy of the researchers.

 

Quote

The early universe was a chaotic mess of gas and matter that only began to coalesce into distinct galaxies hundreds of millions of years after the Big Bang. It would take several billion more years for such galaxies to assemble into massive galaxy clusters - or so scientists had thought.

 

Now astronomers at MIT, the University of Missouri, the University of Florida, and elsewhere, have detected a massive, sprawling, churning galaxy cluster that formed only 3.8 billion years after the Big Bang. Located 10 billion light years from Earth and potentially comprising thousands of individual galaxies, the megastructure is about 250 trillion times more massive than the sun, or 1,000 times more massive than the Milky Way galaxy.

 

The cluster, named IDCS J1426.5+3508 (or IDCS 1426), is the most massive cluster of galaxies yet discovered in the first 4 billion years after the Big Bang.

 

IDCS 1426 appears to be undergoing a substantial amount of upheaval: The researchers observed a bright knot of X-rays, slightly off-center in the cluster, indicating that the cluster's core may have shifted some hundred thousand light years from its center. The scientists surmise that the core may have been dislodged from a violent collision with another massive galaxy cluster, causing the gas within the cluster to slosh around, like wine in a glass that has been suddenly moved.

 

Michael McDonald, assistant professor of physics and a member of MIT's Kavli Center for Astrophysics and Space Research, says such a collision may explain how IDCS 1426 formed so quickly in the early universe, at a time when individual galaxies were only beginning to take shape.

 

"In the grand scheme of things, galaxies probably didn't start forming until the universe was relatively cool, and yet this thing has popped up very shortly after that," McDonald says. "Our guess is that another similarly massive cluster came in and sort of wrecked the place up a bit. That would explain why this is so massive and growing so quickly. It's the first one to the gate, basically."

 

McDonald and his colleagues presented their results this week at the 227th American Astronomical Society meeting in Kissimmee, Florida. Their findings will also be published in The Astrophysical Journal.

 

Cities in space
Galaxy clusters are conglomerations of hundreds to thousands of galaxies bound together by gravity. They are the most massive structures in the universe, and those located relatively nearby, such as the Virgo cluster, are extremely bright and easy to spot in the sky.

 

"They are sort of like cities in space, where all these galaxies live very closely together," McDonald says. "In the nearby universe, if you look at one galaxy cluster, you've basically seen them all - they all look pretty uniform. The further back you look, the more different they start to appear."

However, finding galaxy clusters that are farther away in space - and further back in time - is a difficult and uncertain exercise.

 

In 2012, scientists using NASA's Spitzer Space Telescope first detected signs of IDCS 1426 and made some initial estimates of its mass.

"We had some sense of how massive and distant it was, but we weren't fully convinced," McDonald says. "These new results are the nail in the coffin that proves that it is what we initially thought."

 

"Tip of the iceberg"
To get a more precise estimate of the galaxy cluster's mass, McDonald and his colleagues used data from several of NASA's Great Observatories: the Hubble Space Telescope, the Keck Observatory, and the Chandra X-ray Observatory.

 

"We were basically using three completely different methods to weigh this cluster," McDonald explains.

 

Both the Hubble and Keck Observatories recorded optical data from the cluster, which the researchers analyzed to determine the amount of light that was bending around the cluster as a result of gravity - a phenomenon known as gravitational lensing. The more massive the cluster, the more gravitational force it exerts, and the more light it bends.

 

They also examined X-ray data from the Chandra Observatory to get a sense of the temperature of the cluster. High-temperature objects give off X-rays, and the hotter a galaxy cluster, the more the gas within that cluster has been compressed, making the cluster more massive.

 

From the X-ray data, McDonald and his colleagues also calculated the amount of gas in the cluster, which can be an indication of the amount of matter - and mass - in the cluster.

 

Using all three methods, the group calculated roughly the same mass - about 250 trillion times the mass of the sun. Now, the team is looking for individual galaxies within the cluster to get a sense for how such megastructures can form in the early universe.

 

"This cluster is sort of like a construction site - it's messy, loud, and dirty, and there's a lot that's incomplete," McDonald says. "By seeing that incompleteness, we can get a sense for how [clusters] grow. So far, we've confirmed about a dozen or so galaxies, but we're just seeing the tip of the iceberg, really."

 

He hopes that scientists may get an even better view of IDCS 1426 in 2018, with the launch of the James Webb Space Telescope - an infrared telescope that is hundreds of times more sensitive than the Spitzer Telescope that first detected the cluster.

 

"People had kind of put away this idea of finding clusters in the optical and infrared, in favor of X-ray and radio signatures," McDonald says. "We're now re-emerging and saying it's actually a fantastic way of finding clusters. It suggests that maybe we need to branch out a little more in how we find these things."

http://www.spacedaily.com/reports/Most_distant_massive_galaxy_cluster_identified_999.html

 

--------------------------

 

Ancient Gas Cloud May Be Relic from First Stars

 

computer-simulation-explosion-first-star

Computer simulation of the explosion of the first stars in the universe showing how they send heavy elements out into the young universe. Experimental results in John O'Meara's recent study with colleagues can be used to test the models. Image courtesy Smith, Britton D.; Wise, John H.; O'Shea, Brian W.; Norman, Michael L.; Khochfar, Sadegh.

 

Quote

Saint Michael's College physics professor John O'Meara has teamed with researchers Neil Crighton and Michael Murphy from Australia in the recent discovery of a distant, ancient cloud of gas that may contain the signature of the very first stars that formed in the universe.

 

O'Meara, a co-author on the study, will be presenting the results at the American Astronomical Society meeting in Kissimmee, FL, January 4-8, 2016. The gas cloud his team discovered has an extremely small percentage of heavy elements, such as carbon, oxygen and iron - less than one thousandth the fraction observed in the Sun.

 

It is many billions of light-years distant, and is observed as it was only 1.8 billion years after the Big Bang, say the researchers, whose observations were drawn from data from the Very Large Telescope (VLT), operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile.

 

"Heavy elements weren't manufactured during the Big Bang, they were made later by stars," says lead researcher Neil Crighton, from Australia's Swinburne University of Technology's Center for Astrophysics and Supercomputing. "The first stars were made from completely pristine gas, and we think they formed quite differently from stars today."

 

The researcher say that soon after forming, these first stars - also known as Population III stars - exploded in powerful supernovae, spreading their heavy elements into surrounding pristine clouds of gas. They say the composition of those clouds records information about the first stars and their deaths.

 

"Previous gas clouds found by astronomers show a relatively high enrichment level of heavy elements, so they were probably polluted by more recent generations of stars, diluting and obscuring any signature from the first stars," Crighton says.

 

"This is the first cloud to show the tiny heavy element fraction expected for a cloud enriched by the first stars," said O'Meara. The researchers hope to find more of these systems, where they can measure the ratios of several different kinds of elements.

 

"We can measure the ratio of two elements in this cloud - carbon and silicon. But the value of that ratio doesn't conclusively show that it was enriched by the first stars; later enrichment by older generations of stars is also possible," said O'Meara.

 

"By finding new clouds where we can detect more elements, we will be able to test for the unique pattern of abundances we expect for enrichment by the first stars," he said.

http://www.spacedaily.com/reports/Ancient_Gas_Cloud_May_Be_Relic_from_First_Stars_999.html

 

:)

  • Like 2

Share this post


Link to post
Share on other sites
LOC    988

To think how much has changed in the almost 20 years since I was in college studying Astrophysics.

 

The fact they saw visible light from a Black Hole blows my mind. Space-time expanding faster than light speed blows my mind. My mind is so blown out, it can't comprehend most of this stuff anymore. But I try.

  • Like 2

Share this post


Link to post
Share on other sites
+Mirumir    5,634

 

 

  • Like 4

Share this post


Link to post
Share on other sites
Draggendrop    5,747

Milky Way's Growth Rings Unveiled in 1st Age Map

 

 

milky-way-age.thumb.jpg.c61b1a1137516076

Colored dots over an artist's rendition of the Milky Way reveal the location and ages of stars in the galaxy. Red dots show the older stars, which formed early in the life of the galaxy, while blue dots show the younger generations that have formed since.
Credit: G. Stinson (MPIA)

 

Quote

The first complete age map of the Milky Way shows that the galaxy grew from the inside out.

 

To construct the map, scientists measured the composition and masses of red giant stars to determine their ages. Using a revolutionary technique, the researchers found that older Milky Way stars tend to lie near the center of the spiral galaxy, whereas subsequent generations formed around the spreading edges of the disk.

 

"This is key to understanding galaxy formation," Melissa Ness, a postdoctoral student at the Max Planck Institute for Astronomy in Germany, said at a press conference today (Jan. 8) at the 227th Meeting of the American Astronomical Society in Kissimmee, Florida. Ness lead a group that used the Sloan Digital Sky Survey (SDSS) to study the light, or spectra, from red giant stars to produce the first global age map of the Milky Way.

 

"Measuring the individual ages of stars from their spectra and combining them with chemical information offers the most powerful constraints in the galaxy," she said.

 

Up and out

The familiar spiral arms of the Milky Way lie in a flattened disk of dust and stars. Sorting the stars in this disk by age can help scientists to better understand how the galaxy as a whole evolved. To do that, Ness and her team studied red giant stars, bright stars for which there is a known relationship between age and mass.

 

That relationship depends on the life course of some stars. While some stars end their lives in violent supernova explosions, others don't have enough mass to produce such fireworks. Instead, in the penultimate stage of their lifetimes, stars like the sun swell up and become red giants, which have large radii but low mass.

 

Using the SDSS' Apache Point Observatory Galaxy Evolution Experiment (APOGEE), the team targeted 70,000 red giants to determine their ages and locations. But determining the mass of such a star, and thus its age, has been a long-standing challenge for astronomers. To solve the mystery, the team turned to NASA's Kepler space telescope. Although most famous for the more than 1,000 exoplanets it has discovered, Kepler has also revealed a wealth of information about stars since the observatory's March 2009 launch.

 

In an independent study, Marie Martig of the Swinburne University of Technology in Melbourne, Australia, looked at 2,000 stars whose masses and ages had been previously determined by Kepler. By comparing those values to the measurements of the stars' carbon and nitrogen obtained by APOGEE, she was able to calculate the relationship among red giants' mass, age and carbon and nitrogen abundances. Ness and her team, which included Martig, then used that relationship to determine the mass of the 70,000 red giant stars APOGEE had studied in the disk of the Milky Way.

"This is somewhat revolutionary, because ages have previously been considered very hard to get," Ness said.

 

With this age map, the scientists were able to chart how the Milky Way has grown throughout its lifetime. They found that the more-ancient, 13-billion-year-old stars were the first to form early in the lifetime of the universe. As the young galaxy collected gas and dust in a growing disk around its edges, the material became the site of the next generation of star formation.

 

"Our galaxy grew, and it grew up by growing out," Ness said.

http://www.space.com/31564-milky-way-growth-age-map.html

 

:D

  • Like 2

Share this post


Link to post
Share on other sites
Unobscured Vision    2,650

Oh yeah, I saw this. I thought it was very interesting, for a couple of reasons.

 

1) Older stars towards the Galactic Center?! Whoa! :huh: Would it thus stand to reason that the closer in the star is, the more that the Supermassive Black Hole would tend to disrupt large star formation? More study in the possibility is needed! 

 

2) It also would indicate that Galaxies, as they meander through the Universe, tend to pick up material (Gas, etc) that serve to "jump-start" new star formation -- and that's why we see newer "blue-ish" stars towards the edges. More study in this possibility is also needed!

 

3) Simulations are cool. :yes: 

  • Like 2

Share this post


Link to post
Share on other sites
Draggendrop    5,747

NASA’s next flagship space telescope to get formal start

 

wfirst-afta_0-768x346.thumb.jpg.1885b85d

Artist’s concept of WFIRST. Credit: NASA/Goddard Space Flight Center

 

Quote

NASA officials expect to officially kick off development in February of a multibillion-dollar observatory recycling a grounded top secret spy satellite telescope capable of studying dark energy and directly resolving planets around other stars.

 

The WFIRST mission will launch in the 2020s as NASA’s next flagship-class astrophysics observatory following the James Webb Space Telescope set for liftoff in 2018.

 

Paul Hertz, head of NASA’s astrophysics division, said the mission’s formulation phase is due to begin in February after WFIRST passed a mission concept review in December. The formulation milestone is a year ahead of schedule after Congress sped up WFIRST with extra funding in recent budgets.

 

“This budget (passed in December) lays out funding for WFIRST of $90 million in the current fiscal year, and it also directs us to move forward toward starting the WFIRST project,” Hertz said Jan. 4 in a presentation to a group of astronomers and astrophysicists charged with advising NASA strategic science programs.

 

The $90 million appropriated to the WFIRST project this year is much more than NASA’s $14 million budget request. The space agency had internally planned to pass WFIRST’s formulation gate in 2017.

 

Lawmakers also awarded extra funding to WFIRST in 2014 and 2015, and NASA spent the money to infuse technology development for the observatory’s two main instruments, a multipurpose wide field imager and a coronagraph to see dim planets contrasted against the bright light of stars.

 

“Two years ago, we laid out a set of milestones for the technology development necessary for both the wide field detector technologies and the coronagraph technologies,” Hertz said. “We have made every one of our milestones on schedule so far. That doesn’t mean we’re in the clear, but that means the team is working hard.”

 

Quote

WFIRST was the top recommendation for NASA’s astrophysics program in a National Research Council decadal survey released in 2010. The agency’s policy is to follow cues from the science community encapsulated in the decadal survey reports.

 

The observatory will also carry a stellar coronagraph, the first such device ever flown in space, to blot out the bright light of stars to directly image planets lurking nearby. Direct imaging will allow astronomers to begin measuring the structure and composition of exoplanets, a key step in determining whether the worlds are habitable.

 

NASA’s Kepler space telescope, the most prolific planet-hunter to date, is unable to detect exoplanets unless they cross in front of their parent star and temporarily dim the starlight.

 

WFIRST could discover about 20,000 exoplanets itself, according to a March 2015 report by the mission’s science definition team. So far, Kepler data have contributed to the discovery of about 1,000 worlds around other stars.

more at...

http://spaceflightnow.com/2016/01/13/nasas-next-flagship-space-telescope-to-get-formal-start/

 

:)

  • Like 2

Share this post


Link to post
Share on other sites
Draggendrop    5,747

The Most Powerful Supernova Ever Seen

 

oosupersupernova.thumb.jpg.bd0e9e4e9effa

Artist's impression of PSO J318.5-22     BEIJING PLANETARIUM / JIN MA

 

Quote

Right now, astronomers are viewing a ball of hot gas billions of light years away that is radiating the energy of hundreds of billions of suns. At its heart is an object a little larger than 10 miles across.

 

And astronomers are not entirely sure what it is.

 

If, as they suspect, the gas ball is the result of a supernova, then it's the most powerful supernova ever seen.

 

In this week's issue of the journal Science, they report that the object at the center could be a very rare type of star called a magnetar--but one so powerful that it pushes the energy limits allowed by physics.

 

An international team of professional and amateur astronomers spotted the possible supernova, now called ASASSN-15lh, when it first flared to life in June 2015.

 

Even in a discipline that regularly uses gigantic numbers to express size or distance, the case of this small but powerful mystery object in the center of the gas ball is so extreme that the team's co-principal investigator, Krzysztof Stanek of The Ohio State University, turned to the movie This is Spinal Tap to find a way to describe it.

 

"If it really is a magnetar, it's as if nature took everything we know about magnetars and turned it up to 11," Stanek said. (For those not familiar with the comedy, the statement basically translates to "11 on a scale of 1 to 10.")

 

The gas ball surrounding the object can't be seen with the naked eye, because it's 3.8 billion light years away. But it was spotted by the All Sky Automated Survey for Supernovae (ASAS-SN, pronounced "assassin") collaboration. Led by Ohio State, the project uses a cadre of small telescopes around the world to detect bright objects in our local universe.

 

Though ASAS-SN has discovered some 250 supernovae since the collaboration began in 2014, the explosion that powered ASASSN-15lh stands out for its sheer magnitude. It is 200 times more powerful than the average supernova, 570 billion times brighter than our sun, and 20 times brighter than all the stars in our Milky Way Galaxy combined.

 

"We have to ask, how is that even possible?" said Stanek, professor of astronomy at Ohio State. "It takes a lot of energy to shine that bright, and that energy has to come from somewhere."

 

"The honest answer is at this point that we do not know what could be the power source for ASASSN-15lh," said Subo Dong, lead author of the Science paper and a Youth Qianren Research Professor of astronomy at the Kavli Institute for Astronomy and Astrophysics at Peking University.

He added that the discovery "may lead to new thinking and new observations of the whole class of superluminous supernova."

 

Todd Thompson, professor of astronomy at Ohio State, offered one possible explanation. The supernova could have spawned an extremely rare type of star called a millisecond magnetar, a rapidly spinning and very dense star with a very strong magnetic field.

 

To shine so bright, this particular magnetar would also have to spin at least 1,000 times a second, and convert all that rotational energy to light with nearly 100 percent efficiency, Thompson explained. It would be the most extreme example of a magnetar that scientists believe to be physically possible.

 

"Given those constraints," he said, "will we ever see anything more luminous than this? If it truly is a magnetar, then the answer is basically no."

The Hubble Space Telescope will help settle the question later this year, in part because it will allow astronomers to see the host galaxy surrounding the object. If the team finds that the object lies in the very center of a large galaxy, then perhaps it's not a magnetar at all, and the gas around it is not evidence of a supernova, but instead some unusual nuclear activity around a supermassive black hole.

 

If so, then its bright light could herald a completely new kind of event, said study co-author Christopher Kochanek, professor of astronomy at Ohio State and the Ohio Eminent Scholar in Observational Cosmology. It would be something never before seen in the center of a galaxy.

http://spaceref.com/astronomy/the-most-powerful-supernova-ever-seen.html

 

:)

  • Like 3

Share this post


Link to post
Share on other sites
Draggendrop    5,747

This is a pretty good article that shows how the mirrors, of particular telescopes, are manufactured. Good read with images and a short video of the process.

 

Putting the Polish on Epic-Scale Telescope Mirrors

 

ohara-e6-borosilicate-glass.thumb.jpg.fb

20 tons of Ohara E6 borosilicate glass being loaded onto the mold of one of the GMT’s mirrors.
Credit: Ray Bertram, Steward Observatory, CC BY-ND

 

Quote

When astronomers point their telescopes up at the sky to see distant supernovae or quasars, they’re collecting light that’s traveled millions or even billions of light-years through space. Even huge and powerful energy sources in the cosmos are unimaginably tiny and faint when we view them from such a distance. In order to learn about galaxies as they were forming soon after the Big Bang, and about nearby but much smaller and fainter objects, astronomers need more powerful telescopes.

 

Perhaps the poster child for programs that require extraordinary sensitivity and the sharpest possible images is the search for planets around other stars, where the body we’re trying to detect is extremely close to its star and roughly a billion times fainter. Finding earth-like planets is one of the most exciting prospects for the next generation of telescopes, and could eventually lead to discovering extraterrestrial signatures of life.

 

Detectors in research telescopes are already so sensitive that they capture almost every incoming photon, so there’s only one way to detect fainter objects and resolve structure on finer scales: build a bigger telescope. A large telescope doesn’t just capture more photons, it can also produce sharper images. That’s because the wave nature of light sets a limit to the telescope’s resolution, known as the diffraction limit; the sharpness of the image depends on the wavelength of the light and the telescope’s diameter.

 

As optical scientists, our contribution to the next generation of telescopes is figuring out how to craft the gargantuan mirrors they rely on to collect light from far away. Here’s how we’re perfecting the technology that will enable tomorrow’s astrophysical discoveries.

Good stuff at the link...

http://www.space.com/31645-putting-the-polish-on-epic-scale-telescope-mirrors.html

 

:)

  • Like 1

Share this post


Link to post
Share on other sites
DocM    16,336

The Hawaii Air and Space Port at Kona (KOA)

 

Horizontal takeoffs and landings only, such as XCOR Lynx, the Airbus Spaceplane, SS2 etc.

 

http://www.bizjournals.com/pacific/news/2016/01/15/kona-international-airport-gets-one-step-closer-to.html

 

Kona International Airport gets one step closer to commercial space flights

 

The Hawaii state Office of Aerospace Development is anticipating that environmental assessment for Kona International Airport will be completed in the coming weeks.

 

If the environmental assessment comes back and the results are FONSI — findings of no significant impact —the next step is 30 days of public meetings in Kailua-Kona.


The state has already received several drafts from the Federal Aviation Administration and are just awaiting the final document.

 

If granted the license Kona airport would be among just 10 other locations that are authorized to launch commercial space crafts.

 

The license means space tourism companies can apply for their own individual licenses to use the airport.

Jim Crisafulli, state Office of Aerospace Development director said two companies have already signed nondisclosure agreements expressing their interest in launching space flights from Kona.

 

However, if the assesment finds environmental issues, the office will have to conduct an Environmental Impact Study.

  • Like 3

Share this post


Link to post
Share on other sites
Draggendrop    5,747

The Turbulent Birth of a Quasar
ALMA reveals secrets of most luminous known galaxy in Universe

 

eso1602a.thumb.jpg.7e698385b34016928314d

The most luminous galaxy known in the Universe — the quasar W2246-0526, seen when the Universe was less than 10% of its current age — is so turbulent that it is in the process of ejecting its entire supply of star-forming gas, according to new observations with the Atacama Large Millimeter/submillimeter Array (ALMA).

 

 

Quote

Quasars are distant galaxies with very active supermassive black holes at their centres that spew out powerful jets of particles and radiation. Most quasars shine brightly, but a tiny fraction [1] of these energetic objects are of an unusual type known as Hot DOGs, or Hot, Dust-Obscured Galaxies, including the galaxy WISE J224607.57-052635.0 [2], the most luminous known galaxy in the Universe.

 

For the first time, a team of researchers led by Tanio Díaz-Santos of the Universidad Diego Portales in Santiago, Chile, has used the unique capabilities of ALMA [3] to peer inside W2246-0526 and trace the motion of ionised carbon atoms between the galaxy’s stars.

 

“Large amounts of this interstellar material were found in an extremely turbulent and dynamic state, careening throughout the galaxy at around two million kilometres per hour,” explains lead author Tanio Díaz-Santos.

 

The astronomers believe that this turbulent behaviour could be linked to the galaxy’s extreme luminosity. W2246-0526 blasts out as much light as roughly 350 trillion Suns. This startling brightness is powered by a disc of gas that is superheated as it spirals in on the supermassive black hole at the galaxy’s core. The light from the blazingly bright accretion disc in the centre of this Hot DOG does not escape directly, it is absorbed by a surrounding thick blanket of dust, which re-emits the energy as infrared light [4].

 

This powerful infrared radiation has a direct and violent impact on the entire galaxy. The region around the black hole is at least 100 times more luminous than the rest of the galaxy combined, thus releasing intense yet localised radiation in W2246-0526 that is exerting tremendous pressure on the entire galaxy [5].

 

“We suspected that this galaxy was in a transformative stage of its life because of the enormous amount of infrared energy,” said co-author Peter Eisenhardt, Project Scientist for WISE at NASA's Jet Propulsion Laboratory in Pasadena, California.

 

“ALMA has now shown us that the raging furnace in this galaxy is making the pot boil over,” adds Roberto Assef, also from Universidad Diego Portales and leader of the ALMA observations.

 

If these turbulent conditions continue, the intense infrared radiation would boil away all of the galaxy’s interstellar gas. Models of galaxy evolution based on the new ALMA data indicate that the interstellar gas is already being ejected from the galaxy in all directions.

 

“If this pattern continues, it is possible that W2246 will eventually mature into a more traditional quasar,” concludes Manuel Aravena, also from the Universidad Diego Portales. “Only ALMA, with its unparalleled resolution, can allow us to see this object in high definition and fathom such an important episode in the life of this galaxy.”

 

Notes
[1] Only one of every 3000 quasars observed are classified as Hot DOGs.

[2] The full name of this remarkable object is WISE J224607.57-052635.0, it was found by NASA’s Wide-field Infrared Survey Explorer (WISE) spacecraft and the rest of the name gives the precise location of the quasar on the sky.

[3] ALMA is uniquely capable of detecting the faint, millimetre-wavelength light naturally emitted by atomic carbon.

[4] Because of the expansion of the Universe the infrared radiation from W2246-0526 is redshifted to longer millimetre wavelengths — where ALMA is very sensitive — when it is observed from Earth.

[5] In most other quasars this ratio is much more modest. This process of mutual interaction between the central black hole of a galaxy and the rest of its material is known to astronomers as feedback.

http://www.eso.org/public/news/eso1602/

 

:)

 

It can be quite strange sometimes, to talk about events happening in an image, full well realizing that this is a history shot we are describing. It's outcome has already happened, yet due to the "laws of physics", we are unable to know.

  • Like 3

Share this post


Link to post
Share on other sites
Draggendrop    5,747

Hubble gazes upon a host of dazzling diamonds

 

107216_web.thumb.jpg.3b9003f0a1115a2a586

This NASA/ESA Hubble Space Telescope image features the star cluster Trumpler 14. One of the largest gatherings of hot, massive and bright stars in the Milky Way, this cluster houses some of the most luminous stars in our entire galaxy. NASA/ESA

 

Quote

Single stars are often overlooked in favour of their larger cosmic cousins - but when they join forces, they create truly breathtaking scenes to rival even the most glowing of nebulae or swirling of galaxies. This NASA/ESA Hubble Space Telescope image features the star cluster Trumpler 14. One of the largest gatherings of hot, massive and bright stars in the Milky Way, this cluster houses some of the most luminous stars in our entire galaxy.

 

Around 1100 open clusters have so far been discovered within the Milky Way, although many more are thought to exist. Trumpler 14 is one of these, located some 8000 light-years away towards the centre of the well-known Carina Nebula) .

 

At a mere 500 000 years old - a small fraction of the Pleiades open cluster's age of 115 million years - Trumpler 14 is not only one of the most populous clusters within the Carina Nebula, but also the youngest. However, it is fast making up for lost time, forming stars at an incredible rate and putting on a stunning visual display.

 

This region of space houses one of the highest concentrations of massive, luminous stars in the entire Milky Way - a spectacular family of young, bright, white-blue stars. These stars are rapidly working their way through their vast supplies of hydrogen, and have only a few million years of life left before they meet a dramatic demise and explode as supernovae. In the meantime, despite their youth, these stars are making a huge impact on their environment. They are literally making waves!

 

As the stars fling out high-speed particles from their surfaces, strong winds surge out into space. These winds collide with the surrounding material, causing shock waves that heat the gas to millions of degrees and trigger intense bursts of X-rays. These strong stellar winds also carve out cavities in nearby clouds of gas and dust, and kickstart the formation of new stars.

 

The peculiar arc-shaped cloud visible at the very bottom of this image is suspected to be the result of such a wind. This feature is thought to be a bow shock created by the wind flowing from the nearby star Trumpler 14 MJ 218. Astronomers have observed this star to be moving through space at some 350 000 kilometres per hour, sculpting the surrounding clumps of gas and dust as it does so.

 

Astronomers estimate that around 2000 stars reside within Trumpler 14, ranging in size from less than one tenth to up to several tens of times the mass of the Sun. The most prominent star in Trumpler 14, and the brightest star in this image, is the supergiant HD 93129Aa. It is one of the most brilliant and hottest stars in our entire galaxy.

http://www.spacedaily.com/reports/Hubble_gazes_upon_a_host_of_dazzling_diamonds_999.html

 

http://www.eurekalert.org/multimedia/pub/107216.php

 

----------------------------------

 

Signs of Second Largest Black Hole in the Milky Way

 

oo106862_web.thumb.jpg.a0fd14f3078a55fb0

Intermediate mass black hole near center of Milky Way   KEIO UNIVERSITY

 

Quote

A team of astronomers led by Tomoharu Oka, a professor at Keio University in Japan, has found an enigmatic gas cloud, called CO-0.40-0.22, only 200 light years away from the center of the Milky Way.

 

What makes CO-0.40-0.22 unusual is its surprisingly wide velocity dispersion: the cloud contains gas with a very wide range of speeds. The team found this mysterious feature with two radio telescopes, the Nobeyama 45-m Telescope in Japan and the ASTE Telescope in Chile, both operated by the National Astronomical Observatory of Japan.

 

To investigate the detailed structure, the team observed CO-0.40-0.22 with the Nobeyama 45-m Telescope again to obtain 21 emission lines from 18 molecules. The results show that the cloud has an elliptical shape and consists of two components: a compact but low density component with a very wide velocity dispersion of 100 km/s, and a dense component extending 10 light years with a narrow velocity dispersion.

 

What makes this velocity dispersion so wide? There are no holes inside of the cloud. Also, X-ray and infrared observations did not find any compact objects. These features indicate that the velocity dispersion is not caused by a local energy input, such as supernova explosions.

 

The team performed a simple simulation of gas clouds flung by a strong gravity source. In the simulation, the gas clouds are first attracted by the source and their speeds increase as they approach it, reaching maximum at the closest point to the object. After that the clouds continue past the object and their speeds decrease. The team found that a model using a gravity source with 100 thousand times the mass of the Sun inside an area with a radius of 0.3 light years provided the best fit to the observed data. "Considering the fact that no compact objects are seen in X-ray or infrared observations," Oka, the lead author of the paper that appeared in the Astrophysical Journal Letters, explains "as far as we know, the best candidate for the compact massive object is a black hole."

 

If that is the case, this is the first detection of an intermediate mass black hole. Astronomers already know about two sizes of black holes: stellar-mass black holes, formed after the gigantic explosions of very massive stars; and supermassive black holes (SMBH) often found at the centers of galaxies. The mass of SMBH ranges from several million to billions of times the mass of the Sun. A number of SMBHs have been found, but no one knows how the SMBHs are formed. One idea is that they are formed from mergers of many intermediate mass black holes. But this raises a problem because so far no firm observational evidence for intermediate mass black holes has been found. If the cloud CO-0.40-0.22, located only 200 light years away from Sgr A* (the 400 million solar mass SMBH at the center of the Milky Way), contains an intermediate mass black hole, it might support the intermediate mass black hole merger scenario of SMBH evolution.

 

These results open a new way to search for black holes with radio telescopes. Recent observations have revealed that there are a number of wide-velocity-dispersion compact clouds similar to CO-0.40-0.22. The team proposes that some of those clouds might contain black holes. A study suggested that there are 100 million black holes in the Milky Way Galaxy, but X-ray observations have only found dozens so far. Most of the black holes may be "dark" and very difficult to see directly at any wavelength. "Investigations of gas motion with radio telescopes may provide a complementary way to search for dark black holes" said Oka. "The on-going wide area survey observations of the Milky Way with the Nobeyama 45-m Telescope and high-resolution observations of nearby galaxies using the Atacama Large Millimeter/submillimeter Array (ALMA) have the potential to increase the number of black hole candidates dramatically."

http://spaceref.com/astronomy/signs-of-second-largest-black-hole-in-the-milky-way.html

 

Background research on Intermediate Mass Black Holes (IMBH)

 

Russian volunteer programmers helped the Lomonosov MSU to find the mysterious black holes

 

Quote

The term "black holes" was first used in the mid-20th century by theoretical physicist John Wheeler. This term denotes relativistic supermassive objects that are invisible in all electromagnetic waves, but a great number of astrophysical effects confirms their existence.

 

There are two basic types of black holes known to scientists according to observations: supermassive black holes and stellar-mass black holes. It is generally believed that stellar-mass black holes are formed in the end of the evolution of massive stars, when stellar energy sources are exhausted, and the star collapse due to its own gravity. Theoretical calculations impose restrictions on their mass to the extent of 5-50 solar masses.

 

It's less clear how supermassive black holes come to existence. Masses of these black holes sitting in the center of most galaxies range between millions and billions of solar masses. Quasars, the active galactic nuclei, are supermassive black holes observed by astronomers at high redshift. It means that these giants existed in the first few hundred million years after the Big Bang. Ivan Zolotukhin, who works at the Research Institute of Astrophysics and Planetology (Toulouse), said: "The astronomers look for black holes of intermediate mass, because no black hole that weighs a billion times more than the Sun could have been formed without them in just 700 million years."

More at the link...

http://www.eurekalert.org/pub_releases/2016-01/lmsu-rvp012016.php

 

:)

  • Like 1

Share this post


Link to post
Share on other sites
Draggendrop    5,747

How the first stars sprung to life in early universe

 

eso_ump.jpg

A team of researchers has observed the brightest ultra metal-poor star ever discovered. Image courtesy ESO/Beletsky/DSS1 + DSS2 + 2MASS. 

 

Quote

A team of researchers has observed the brightest ultra metal-poor star ever discovered. The star is a rare relic from the Milky Way's formative years. As such, it offers astronomers a precious opportunity to explore the origin of the first stars that sprung to life within our galaxy and the universe.

 

A Brazilian-American team including Vinicius Placco, a research assistant professor at the University of Notre Dame and a member of JINA-CEE (Joint Institute for Nuclear Astrophysics - Center for the Evolution of the Elements), and led by Jorge Melendez from the University of Sao Paulo used two of European Southern Observatory's telescopes in Chile to discover this star, named 2MASS J18082002-5104378.

 

The star was spotted in 2014 using ESO's New Technology Telescope. Follow-up observations using ESO's Very Large Telescope discovered that, unlike younger stars such as the sun, this star shows an unusually low abundance of what astronomers call metals - elements heavier than hydrogen and helium. It is so devoid of these elements that it is known as an ultra metal-poor star.

 

Although thought to be ubiquitous in the early universe, metal-poor stars are now a rare sight within both the Milky Way and other nearby galaxies. Metals are formed during nuclear fusion within stars, and are spread throughout the interstellar medium when some of these stars grow old and explode.

 

Subsequent generations of stars therefore form from increasingly metal-rich material. Metal-poor stars, however, formed from the unpolluted environment that existed shortly after the Big Bang. Exploring stars such as 2MASS J18082002-5104378 may unlock secrets about their formation, and show what the universe was like at its very beginning.

 

The results have been published in Astronomy and Astrophysics. In addition to Placco and Melendez, the team consisted of Marcelo Tucci-Maia, Universidade de Sao Paulo, IAG, Brazil; Ivan Ramirez, University of Texas at Austin, McDonald Observatory and Department of Astronomy; Ting S. Li, Texas Aa and M University, Department of Physics and Astronomy; and Gabriel Perez, Universidade de Sao Paulo, IAG, Brazil.

http://www.spacedaily.com/reports/How_the_first_stars_sprung_to_life_in_early_universe_999.html

 

-------------------------

 

Dying Star Betelgeuse Keeps Its Cool ... and Astronomers Are Puzzled

 

direct-sky-image-betelgeuse.thumb.jpg.2a

A direct-sky image of Betelgeuse, a star that is shedding its mass as it nears the end of its life.
Credit: ESO/Digitized Sky Survey 2. Acknowledgment: Davide De Martin.

 

Quote

The bright, red star Betelgeuse, in the constellation Orion, has entered the twilight of its life. Like many stars of a similar size that reach the end of the road, Betelgeuse is slowly shedding its mortal coil — by ejecting much of its mass out into space.

 

This phase of star death is extremely common in the universe — in about 5 billion years, when the sun starts to die, it too will become a "red giant." It will shed much of its mass and  swell to such an enormous size that it will engulf Mercury, Venus and Earth. But new observations of Betelgeuse show that scientists still can't explain what causes a red giant's massive expulsion of matter.

 

"In the next million years, if Betelgeuse lives that long, it is going to shed about a quarter of its current mass, and the problem is we don't understand the basic physics of how that happens," said Graham Harper, an astrophysicist and senior research associate at the University of Colorado, Boulder. "This is a big astrophysical problem."  

 

Earlier this month, at the 227th meeting of the American Astronomical Society (AAS), Harper presented new observations of Betelgeuse that appear to further complicate the story of how these red giant and supergiant stars shed so much mass.

 

The findings show that the gas moving away from the star is much colder than expected, and so far, scientists can't come up with a mechanism that can eject so much mass from the star, but also generate so little heat. It's a problem of balancing energy in and energy out and right now the accounting doesn't add up. 

 

betelgeuse_collage.thumb.jpg.a25f0a1dd0e

This collage shows Betelgeuse as it appears in the Orion constellation (left; the star is identified by the marker), a zoom toward Betelgeuse (middle), and the sharpest-ever image of this red supergiant, obtained the European Southern Observatory's Very Large Telescope. 
Credit: ESO, P. Kervella, Digitized Sky Survey 2 and A. Fujii

 

More at the link...

http://www.space.com/31693-dying-star-betelgeuse-puzzles-astronomers.html

 

---------------------------

 

Explore Galaxies Far, Far Away at Internet Speeds

 

ooSky-Viewer.thumb.jpg.210c799a4cd69eb8f

Interactive Sky Viewer tool (DECaLS browser)   DUSTIN LANG/UNIVERSITY OF TORONTO

 

Quote

No need for hyperdrive: Scientists have released an "expansion pack" for a virtual tour of the universe that you can enjoy from the comfort of your own computer.

 

The latest version of the publicly accessible images of the sky, which can be viewed using an interactive Sky Viewer tool, roughly doubles the size of the searchable universe from the project's original release in May.

 

The images for this sky-mapping project, dubbed DECaLS (for Dark Energy Camera Legacy Survey) were taken by the 520-megapixel Dark Energy Survey Camera (DECam).

 

The scientific aim of DECaLS is to identify a select set of about 40 million galaxies and 2.5 million or more quasars -- extremely luminous sources in the distant universe powered by massive black holes -- that will be the focus of a ground-breaking project known as the Dark Energy Spectroscopic Instrument (DESI).

 

The DESI collaboration, managed at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), is building the new instrument for the Mayall 4-meter telescope at Kitt Peak National Observatory.

 

DESI will measure the distances to the galaxies identified by the survey, create the largest, most detailed 3-D map of the universe, and provide the most precise measurement of the expansion history of the universe over the last 12 billion years. The project will explore the effects of dark energy, a mysterious force that is causing this expansion to accelerate.

 

The DECaLS maps of the sky are more than three times deeper than those from a predecessor survey, the Sloan Digital Sky Survey. In addition, DECaLS will map a larger region than the Sloan survey, eventually covering about one-third of the sky. The images can be viewed by the public using the Sky Viewer, built by co-investigator Dustin Lang of University of Toronto.

 

The viewer allows users to toggle between various views, comparing images or models from the DECaLS data set to images from past surveys of the sky. You can also click to view labels for space objects, including stars and galaxies.

 

The latest DECaLS Sky Viewer release contains about 370 million stars and galaxies, said Berkeley Lab's David Schlegel, co-lead investigator for the DECaLS project and project scientist for DESI. Berkeley Lab scientists and engineers created the light-sensitive charge-coupled devices (CCDs) integral to the sensitive, high-resolution images.

 

"When we finish this we'll have a few billion objects," Schlegel said. DECaLS is collecting images in three different visual bands of color, which are featured in Sky Viewer, and in four bands of infrared color. The project will collect data through at least 2018.

 

"We are running the imaging surveys of the sky as completely public projects," said Arjun Dey, an astronomer at the National Optical Astronomy Observatory, and co-lead with Schlegel of the DECaLS project. Project data and catalogs are made available to researchers and the public as soon as they are produced. This approach has enabled many groups not involved in the DECaLS project to undertake a broad variety of research projects.

"The Sloan imaging survey saw very few galaxies beyond about 20 percent of the way across the visible universe," Schlegel said. "For these new DECaLS imaging sets, we are seeing many galaxies about half of the way across the visible universe. We will be mapping 10 times more volume than Sloan did."

 

Dey said, "The potential for new discoveries is very exciting."

 

As more is learned about objects from observations, it will improve the algorithms used to build a better virtual model of the universe containing simulated galaxies, quasars, stars and other objects. "Ideally, the model will become a perfect representation" that syncs with actual images and helps to identify previously unknown objects," Schlegel said. "We're far from there now, but we're a lot closer than we've ever been."

In parallel to the sky-mapping project is an effort to develop mathematical algorithms to automatically identify the objects in the images.

The DECaLS survey is somewhat unique in placing its data immediately in the public domain. "The raw images are all available. All of the code we're using is open source," Schlegel said.

 

"After all, the resources that enable this project are supported by taxpayers," Dey said. "The project belongs to them."

 

This openness makes possible research by citizen-science projects like Galaxy Zoo, which is using a "wisdom of crowds" approach to scour some of DECaLS's galaxy data. Tens of thousands of the galaxy images collected by DECaLS are being fed into Galaxy Zoo, which allows members of the public to identify and describe their features. These classifications can ultimately help scientists to sort and analyze galaxies, to understand more about their ages and how they formed, and to develop machine-learning algorithms that train computers to automatically do these characterizations.

 

The Galaxy Zoo platform imported a first batch of about 30,000 galaxies from DECaLS into its system in September, with an aim to gather about 1.2 million total classifications (40 per galaxy). Galaxy Zoo will import additional sets of galaxies as its users finish up the earlier batch of classifications. Galaxy Zoo also imports galaxy data from other sources, including simulated galaxies generated by computer models.

 

"What we've always done is tried to get dozens of people to weigh in on each galaxy separately," said Kyle Willett, lead data scientist for Galaxy Zoo and a research associate at the University of Minnesota. "Our goal for the DECaLS data is to have 40 people look at each galaxy."

 

The Sky Viewer tool is hosted by Berkeley Lab's National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility.

The DECaLS project was awarded telescope time at the Blanco Telescope at the Cerro-Tololo Inter-American Observatory through the National Optical Astronomical Observatory's Survey program. The project is an international collaboration, and is partly supported by the DESI project and NOAO. The Dark Energy Camera used for the DECaLS observations was constructed by the Dark Energy Survey Collaboration with support from the U. S. Department of Energy Office of High Energy Physics and the National Science Foundation.

 

The DESI project is funded, in large part, by the U. S. Department of Energy, Office of Science. The DECaLS project NOAO and Cerro-Tololo Inter-American Observatory are operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation.

http://spaceref.com/astronomy/explore-galaxies-far-far-away-at-internet-speeds.html

 

DECaLS browser

http://legacysurvey.org/viewer

 

:)

  • Like 2

Share this post


Link to post
Share on other sites
Draggendrop    5,747

Lonely Planet Finds a Mum a Trillion Km Away

 

extrasolar-lost-world-lg.thumb.jpg.b0524

illustration only

 

Quote

Astronomers studying a lonely planet drifting through space have found its mum; a star a trillion kilometers away.

 

The planet, known as 2MASS J2126-8140, has an orbit around its host star that takes nearly a million Earth years and is more than 140 times wider than Pluto's. This makes it easily the largest solar system ever found.

 

"We were very surprised to find such a low-mass object so far from its parent star," said Dr. Simon Murphy of The Australian National University (ANU) Research School of Astronomy and Astrophysics.

 

"There is no way it formed in the same way as our solar system did, from a large disc of dust and gas."

 

Only a handful of extremely wide pairs of this kind have been found in recent years. The distance between the new pair is 6,900 astronomical units (AU) - 1,000,000,000,000 kilometers or 0.1 light-year - nearly three times the previous widest pair, which is 2,500 AU (370,000,000,000 km).

 

2MASS J2126-8140's parent is a red dwarf star called TYC 9486-927-1. At that distance, it would appear as only a moderately bright star in the sky, and light would take about a month to reach the planet.

 

Dr. Murphy is part of an international team of scientists that studied 2MASS J2126-8140, a gas giant planet around 12 to 15 times the mass of Jupiter, as part of a survey of several thousand young stars and brown dwarfs close to our solar system.

 

Once they realized 2MASS J2126-8140 and TYC 9486-927-1 were a similar distance from the Earth - about 100 light-years - they compared the motion of the two through space and realized they were moving together.

 

"We can speculate they formed 10 million to 45 million years ago from a filament of gas that pushed them together in the same direction," Dr. Murphy said.

 

"They must not have lived their lives in a very dense environment. They are so tenuously bound together that any nearby star would have disrupted their orbit completely."

http://www.spacedaily.com/reports/Lonely_Planet_Finds_a_Mum_a_Trillion_Km_Away_999.html

 

http://www.popsci.com/biggest-solar-system-ever-found-is-very-very-big

 

:)

  • Like 1

Share this post


Link to post
Share on other sites
Unobscured Vision    2,650

It's probably a capture, or an ejection. They need time to study the orbital track, then they'll know for certain.

  • Like 1

Share this post


Link to post
Share on other sites
LOC    988

Actually if I remember from the article I read a few days ago they believe they both formed out of a filiment of gas together when some sort of shockwave hit it from a Supernova etc. Compression created clumpiness and you get star and planet, and stuffs.

 

But a capture or ejection would have been my guess as well.

  • Like 1

Share this post


Link to post
Share on other sites
Draggendrop    5,747

Yes...quite right...from above post..

 

Quote

Once they realized 2MASS J2126-8140 and TYC 9486-927-1 were a similar distance from the Earth - about 100 light-years - they compared the motion of the two through space and realized they were moving together.
 
"We can speculate they formed 10 million to 45 million years ago from a filament of gas that pushed them together in the same direction," Dr. Murphy said.
 
"They must not have lived their lives in a very dense environment. They are so tenuously bound together that any nearby star would have disrupted their orbit completely."

This is a relatively young age after initial formation, and either may not have been exposed to an outside force, as of yet.

:)

Share this post


Link to post
Share on other sites
Draggendrop    5,747

The Milky Way's clean and tidy galactic neighbor

 

107394_web.thumb.jpg.b99687771c4885338f9

This image, captured with the OmegaCAM camera on ESO's VLT Survey Telescope in Chile, shows an unusually clean small galaxy. IC 1613 contains very little cosmic dust, allowing astronomers to explore its contents with great clarity.

 

Quote

IC 1613 is a dwarf galaxy in the constellation of Cetus (The Sea Monster). This VST image shows the galaxy's unconventional beauty, all scattered stars and bright pink gas, in great detail.

 

German astronomer Max Wolf discovered IC 1613's faint glow in 1906. In 1928, his compatriot Walter Baade used the more powerful 2.5-metre telescope at the Mount Wilson Observatory in California to successfully make out its individual stars. From these observations, astronomers figured out that the galaxy must be quite close to the Milky Way, as it is only possible to resolve single pinprick-like stars in the very nearest galaxies to us.

Astronomers have since confirmed that IC 1613 is indeed a member of the Local Group, a collection of more than 50 galaxies that includes our home galaxy, the Milky Way. IC 1613 itself lies just over 2.3 million light-years away from us. It is relatively well-studied due to its proximity; astronomers have found it to be an irregular dwarf that lacks many of the features, such as a starry disc, found in some other diminutive galaxies.

 

However, what IC 1613 lacks in form, it makes up for in tidiness. We know IC 1613's distance to a remarkably high precision, partly due to the unusually low levels of dust lying both within the galaxy and along the line of sight from the Milky Way - something that enables much clearer observations.

 

The second reason we know the distance to IC 1613 so precisely is that the galaxy hosts a number of notable stars of two types: Cepheid variables and RR Lyrae variables. Both types of star rhythmically pulsate, growing characteristically bigger and brighter at fixed intervals http://www.eso.org/public/news/eso1311/

 

As we know from our daily lives on Earth, shining objects such as light bulbs or candle flames appear dimmer the further they are away from us. Astronomers can use this simple piece of logic to figure out exactly how far away things are in the Universe-- so long as they know how bright they really are, referred to as their intrinsic brightness.

 

Cepheid and RR Lyrae variables have the special property that their period of brightening and dimming is linked directly to their intrinsic brightness. So, by measuring how quickly they fluctuate astronomers can work out their intrinsic brightness. They can then compare these values to their apparent measured brightness and work out how far away they must be to appear as dim as they do.

 

Stars of known intrinsic brightness can act like standard candles, as astronomers say, much like how a candle with a specific brightness would act as a good gauge of distance intervals based on the observed brightness of its flame's flicker.

 

Using standard candles - such as the variable stars within IC 1613 and the less-common Type Ia supernova explosions, which can seen across far greater cosmic distances - astronomers have pieced together a cosmic distance ladder, reaching deeper and deeper into space.

 

Decades ago, IC 1613 helped astronomers work out how to utilise variable stars to chart the Universe's grand expanse. Not bad for a little, shapeless galaxy.

http://www.spacedaily.com/reports/The_Milky_Ways_clean_and_tidy_galactic_neighbor_999.html

 

http://www.eurekalert.org/multimedia/pub/107394.php

 

with reference article (mentioned in post) for measurement...

 

Measuring the Universe More Accurately Than Ever Before

http://www.eso.org/public/news/eso1311/

 

------------------------------------------

 

Monstrous Cloud Boomerangs Back to Our Galaxy

 

oohs-2016-04-b-print-1.thumb.jpg.57e9cc3

Smith Cloud         STSC

 

Quote

Hubble Space Telescope astronomers are finding that the old adage "what goes up must come down" even applies to an immense cloud of hydrogen gas outside our Milky Way galaxy. The invisible cloud is plummeting toward our galaxy at nearly 700,000 miles per hour.

 

Though hundreds of enormous, high-velocity gas clouds whiz around the outskirts of our galaxy, this so-called "Smith Cloud" is unique because its trajectory is well known. New Hubble observations suggest it was launched from the outer regions of the galactic disk, around 70 million years ago. The cloud was discovered in the early 1960s by doctoral astronomy student Gail Smith, who detected the radio waves emitted by its hydrogen.

 

The cloud is on a return collision course and is expected to plow into the Milky Way's disk in about 30 million years. When it does, astronomers believe it will ignite a spectacular burst of star formation, perhaps providing enough gas to make 2 million Suns.

 

"The cloud is an example of how the galaxy is changing with time," explained team leader Andrew Fox of the Space Telescope Science Institute in Baltimore, Maryland. "It's telling us that the Milky Way is a bubbling, very active place where gas can be thrown out of one part of the disk and then return back down into another."

 

"Our galaxy is recycling its gas through clouds, the Smith Cloud being one example, and will form stars in different places than before. Hubble's measurements of the Smith Cloud are helping us to visualize how active the disks of galaxies are," Fox said.

 

Astronomers have measured this comet-shaped region of gas to be 11,000 light-years long and 2,500 light-years across. If the cloud could be seen in visible light, it would span the sky with an apparent diameter 30 times greater than the size of the full Moon.

 

Astronomers long thought that the Smith Cloud might be a failed, starless galaxy, or gas falling into the Milky Way from intergalactic space. If either of these scenarios proved true, the cloud would contain mainly hydrogen and helium, not the heavier elements made by stars. But if it came from within the galaxy, it would contain more of the elements found within our Sun.

 

The team used Hubble to measure the Smith Cloud's chemical composition for the first time, to determine where it came from. They observed the ultraviolet light from the bright cores of three active galaxies that reside billions of light-years beyond the cloud. Using Hubble's Cosmic Origins Spectrograph, they measured how this light filters through the cloud.

 

In particular, they looked for sulfur in the cloud which can absorb ultraviolet light. "By measuring sulfur, you can learn how enriched in sulfur atoms the cloud is compared to the Sun," Fox explained. Sulfur is a good gauge of how many heavier elements reside in the cloud.

 

The astronomers found that the Smith Cloud is as rich in sulfur as the Milky Way's outer disk, a region about 40,000 light-years from the galaxy's center (about 15,000 light-years farther out than our Sun and solar system). This means that the Smith Cloud was enriched by material from stars. This would not happen if it were pristine hydrogen from outside the galaxy, or if it were the remnant of a failed galaxy devoid of stars. Instead, the cloud appears to have been ejected from within the Milky Way and is now boomeranging back.

 

Though this settles the mystery of the Smith Cloud's origin, it raises new questions: How did the cloud get to where it is now? What calamitous event could have catapulted it from the Milky Way's disk, and how did it remain intact? Could it be a region of dark matter -- an invisible form of matter -- that passed through the disk and captured Milky Way gas? The answers may be found in future research.

http://spaceref.com/astronomy/monstrous-cloud-boomerangs-back-to-our-galaxy.html

 

That would be an amazing star creation event to see, but we mere mortals only live microseconds compared to stellar formation time lines...

  • Like 2

Share this post


Link to post
Share on other sites
Draggendrop    5,747

NASA Webb Telescope mirrors installed with robotic arm precision

 

107676_web.thumb.jpg.7387f65cc022e64dbf5

A robotic arm called the Primary Mirror Alignment and Integration Fixture is used to lift and lower each of Webb's 18 primary flight mirror segments to their locations on the telescope structure.   NASA

 

Quote

Inside a massive clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland the James Webb Space Telescope team is steadily installing the largest space telescope mirror ever. Unlike other space telescope mirrors, this one must be pieced together from segments using a high-precision robotic arm.

 

The team uses a robotic arm called the Primary Mirror Alignment and Integration Fixture to lift and lower each of Webb's 18 primary flight mirror segments to their locations on the telescope structure. Each of the mirrors is made with beryllium, chosen for its properties to withstand the super cold temperatures of space. Each segment also has a thin gold coating to reflect infrared light. These mirror segments will function as one when the telescope is in orbit.

 

"In order for the combination of mirror segments to function as a single mirror they must be placed within a few millimeters of one another, to fraction-of-a-millimeter accuracy. A human operator cannot place the mirrors that accurately, so we developed a robotic system to do the assembly," said NASA's James Webb Space Telescope Program Director Eric Smith, at Headquarters in Washington.

 

To precisely install the segments, the robotic arm can move in six directions to maneuver over the telescope structure. While one team of engineers maneuvers the robotic arm, another team of engineers simultaneously takes measurements with lasers to ensure each mirror segment is placed, bolted and glued perfectly before moving to the next.

 

"While the team is installing the mirrors there are references on the structure and the mirrors that allow the team to understand where the final mirror surface is located," said Harris Corporation's James Webb Space Telescope's Assembly Integration and Test Director Gary Matthews Greenbelt, Maryland.

 

The team uses reference points on the telescope structure called Spherically Mounted Retroreflectors to accomplish this feat. A laser tracker, similar to the ones used by surveyors, looks at those reference points and can determine where the mirror segments go.

 

"Instead of using a measuring tape, a laser is used to measure distance very precisely," said Matthews. "Based off of those measurements a coordinate system is used to place each of the primary mirror segments. The engineers can move the mirror into its precise location on the telescope structure to within the thickness of a piece of paper."

 

Harris Corporation engineers are helping build NASA's ultra-powerful James Webb Space Telescope. Harris is responsible for integrating components made by various members of the team to form the optical telescope element, which is the portion of the telescope that will collect light and provide sharp images of deep space.

http://www.spacedaily.com/reports/NASA_Webb_Telescope_mirrors_installed_with_robotic_arm_precision_999.html

 

http://www.eurekalert.org/multimedia/pub/107676.php

 

:D

  • Like 1

Share this post


Link to post
Share on other sites
Draggendrop    5,747

Hubble Finds Misbehaving Spiral

 

hubble-edge-on-spiral-galaxy-lo95-0313-1

Image credit: ESA/Hubble and NASA; acknowledgement, Judy Schmidt

 

Quote

Despite its unassuming appearance, the edge-on spiral galaxy captured in the left half of this NASA/ESA Hubble Space Telescope image is actually quite remarkable.

 

Located about one billion light-years away in the constellation of Eridanus, this striking galaxy - known as LO95 0313-192 - has a spiral shape similar to that of the Milky Way. It has a large central bulge, and arms speckled with brightly glowing gas mottled by thick lanes of dark dust.

 

Its companion, sitting in the right of the frame, is known rather unpoetically as [LOY2001] J031549.8-190623.

 

Jets, outbursts of superheated gas moving at close to the speed of light, have long been associated with the cores of giant elliptical galaxies, and galaxies in the process of merging.

 

However, in an unexpected discovery, astronomers found LO95 0313-192, even though it is a spiral galaxy, to have intense radio jets spewing out from its center. The galaxy appears to have two more regions that are also strongly emitting in the radio part of the spectrum, making it even rarer still.

 

The discovery of these giant jets in 2003 - not visible in this image, but indicated in this earlier Hubble composite - has been followed by the unearthing of a further three spiral galaxies containing radio-emitting jets in recent years.

 

This growing class of unusual spirals continues to raise significant questions about how jets are produced within galaxies, and how they are thrown out into the cosmos.

http://www.spacedaily.com/reports/Hubble_Finds_Misbehaving_Spiral_999.html

 

:)

  • Like 2

Share this post


Link to post
Share on other sites
Draggendrop    5,747

Blast from Black Hole in a Galaxy Far, Far Away

 

oopictora_lg.thumb.jpg.c52faf3a82663f1ab

Pictor A galaxy      NASA

 

Quote

The Star Wars franchise has featured the fictitious "Death Star," which can shoot powerful beams of radiation across space. The universe, however, produces phenomena that often surpass what science fiction can conjure.

 

The Pictor A galaxy is one such impressive object. This galaxy, located nearly 500 million light-years from Earth, contains a supermassive black hole at its center. A huge amount of gravitational energy is released as material swirls towards the event horizon, the point of no return for infalling material. This energy produces an enormous beam, or jet, of particles traveling at nearly the speed of light into intergalactic space.

 

To obtain images of this jet, scientists used NASA's Chandra X-ray Observatory at various times over 15 years. Chandra's X-ray data (blue) have been combined with radio data from the Australia Telescope Compact Array (red) in this new composite image.

 

By studying the details of the structure seen in both X-rays and radio waves, scientists seek to gain a deeper understanding of these huge collimated blasts.

 

The jet [to the right] in Pictor A is the one that is closest to us. It displays continuous X-ray emission over a distance of 300,000 light-years. By comparison, the entire Milky Way is about 100,000 light-years in diameter. Because of its relative proximity and Chandra's ability to make detailed X-ray images, scientists can look at detailed features in the jet and test ideas of how the X-ray emission is produced.

 

In addition to the prominent jet seen pointing to the right in the image, researchers report evidence for another jet pointing in the opposite direction, known as a "counterjet." While tentative evidence for this counterjet had been previously reported, these new Chandra data confirm its existence. The relative faintness of the counterjet compared to the jet is likely due to the motion of the counterjet away from the line of sight to the Earth.

The labeled image shows the location of the supermassive black hole, the jet and the counterjet. Also labeled is a "radio lobe" where the jet is pushing into surrounding gas and a "hotspot" caused by shock waves -- akin to sonic booms from a supersonic aircraft -- near the tip of the jet.

 

The detailed properties of the jet and counterjet observed with Chandra show that their X-ray emission likely comes from electrons spiraling around magnetic field lines, a process called synchrotron emission. In this case, the electrons must be continuously re-accelerated as they move out along the jet. How this occurs is not well understood

 

The researchers ruled out a different mechanism for producing the jet's X-ray emission. In that scenario, electrons flying away from the black hole in the jet at near the speed of light move through the sea of cosmic background radiation (CMB) left over from the hot early phase of the universe after the Big Bang. When a fast-moving electron collides with one of these CMB photons, it can boost the photon's energy up into the X-ray band.

 

The X-ray brightness of the jet depends on the power in the beam of electrons and the intensity of the background radiation. The relative brightness of the X-rays coming from the jet and counterjet in Pictor A do not match what is expected in this process involving the CMB, and effectively eliminate it as the source of the X-ray production in the jet.

 

"Deep Chandra Observations of Pictor A," M. J. Hardcastle et al., 2016 Feb. 1, Monthly Notices of the Royal Astronomical Society [http://mnras.oxfordjournals.org/content/455/4/3526, preprint: http://arxiv.org/abs/1510.08392]. The authors are Martin Hardcastle from the University of Hertfordshire in the UK, Emil Lenc from the University of Sydney in Australia, Mark Birkinshaw from the University of Bristol in the UK, Judith Croston from the University of Southampton in the UK, Joanna Goodger from the University of Hertfordshire, Herman Marshall from the Massachusetts Institute of Technology in Cambridge, MA, Eric Perlman from the Florida Institute of Technology, Aneta Siemiginowska from the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA, Lukasz Stawarz from Jagiellonian University in Poland and Diana Worrall from the University of Bristol.

http://spaceref.com/astronomy/blast-from-black-hole-in-a-galaxy-far-far-away.html

 

http://arxiv.org/abs/1510.08392

 

The associated image supplied, is missing the labels mentioned in the article....?

 

:)

  • Like 2

Share this post


Link to post
Share on other sites
Draggendrop    5,747

ALMA peers inside the brightest known quasar

 

galaxy-W2246-0526-640x416.thumb.jpg.b05f

Artist's impression of W2246-0526, a galaxy shining in infrared with the luminosity of 350 trillion suns.

 

Quote

Brightness can mean different things. A nearby candle is brighter than an identical one in the distance. To avoid confusion, astronomers use the word "luminosity" rather than brightness to indicate the total amount of light that an object puts out. By that measure, W2246-0526 is the brightest—the most luminous—galaxy in the observable Universe.

 

A group of researchers has now taken advantage of the abilities of the Atacama Large Millimeter Array (ALMA) to take a look inside W2246-0526 and see what’s going on there.

 

The cause of the brightness is not mysterious. The galaxy’s incredibly bright core, which outshines the rest of its stars by a factor of over 100, is home to a very active supermassive black hole (SMBH). While nearly every galaxy houses a SMBH, only the most active ones earn the title of quasar. ("Active" in this context means that the black hole is rapidly consuming a lot of matter, producing its incredible light output through friction as it does.)

 

And only a tiny fraction of quasars earns the title of Hot DOG, or Hot Dust Obscured Galaxy, because of their incredible luminosity and the temperature of their dust. W2246-0526 belongs to both of these elite clubs.

 

Quote

Forceful light…

The light emitted by the SMBH is absorbed by a thick layer of dust and subsequently re-emitted as infrared light. This light can have an effect on the surrounding matter. While it may not seem like it in everyday life, light can actually push on things. (Everyday lights aren’t strong enough to create a noticeable acceleration.) With enough light, this can become a significant force.

 

In gas-filled galaxies like W2246-0526, the infrared light can push on the galaxy’s gas, even pushing some out of the galaxy entirely. That makes a big difference for the galaxy’s evolution, since it’s eliminating some of the gas that contracts to form stars. So the researchers looked at the gas and its motion.

 

When looking at ionized carbon, they found that it’s moving at an incredible rate, making the galaxy a churning, turbulent cauldron of gas. “Large amounts of this interstellar material were found in an extremely turbulent and dynamic state, careening throughout the galaxy at around two million kilometers per hour,” said lead author Tanio Díaz-Santos.

 

The speed of the gas throughout the galaxy is mostly uniform, suggesting that any unevenness in the light source was being smoothed out by the motion of the gas itself. “Such a large, homogeneous velocity dispersion indicates a highly turbulent medium,” the authors write in their paper.

“Making the pot boil over”

 

The galaxy’s gas is zooming around at incredible speeds, and that will have consequences. Because the gas is whipping around the galaxy so fast, some of it manages to escape the galaxy’s gravity and depart into intergalactic space in an “unprecedented, homogeneous, large-scale turbulent outflow,” as the authors describe it in the paper. Over time, this process will ultimately strip the galaxy of most of its gas.

 

“We suspected that this galaxy was in a transformative stage of its life because of the enormous amount of infrared energy,” said co-author Peter Eisenhardt, project scientist for WISE at NASA's Jet Propulsion Laboratory in Pasadena, California.

 

“If this pattern continues, it is possible that W2246 will eventually mature into a more traditional quasar,” added Manuel Aravena, also from the Universidad Diego Portales and another of the paper’s authors. “Only ALMA, with its unparalleled resolution, can allow us to see this object in high definition and fathom such an important episode in the life of this galaxy.”

 

W2246-0526 is in a key stage in its evolution. We’re catching it right as light from the quasar at its core is just starting to push out the gas, preventing new stars from forming. This will transform it into an ordinary quasar and ultimately a normal elliptical galaxy, the kind we see throughout the Universe.

 

As such, W2246-0526 is an excellent laboratory for studying how gas behaves in an extreme environment, in particular one that existed when the Universe was only a tenth of its current age, during an era when the Universe was ramping up to the fastest period of star formation and SMBH growth in history. It's an excellent place to look for clues to how modern galaxies developed.

http://arstechnica.com/science/2016/02/alma-peers-inside-the-brightest-known-quasar/

 

http://www.eso.org/public/news/eso1602/?lang

 

:D  Hotdogs and hyperdrive.....yesssssss.

  • Like 2

Share this post


Link to post
Share on other sites
Draggendrop    5,747

ALMA Finds Unexpectedly Cold Grains in Planet-forming Disc

 

ooeso1604a.thumb.jpg.b59af6cc6f86dc42e1d

2MASS J16281370-2431391    ESO

 

Quote

The international team, led by Stephane Guilloteau at the Laboratoire d'Astrophysique de Bordeaux, France, measured the temperature of large dust grains around the young star 2MASS J16281370-2431391 in the spectacular Rho Ophiuchi star formation region, about 400 light-years from Earth.

 

This star is surrounded by a disc of gas and dust -- such discs are called protoplanetary discs as they are the early stages in the creation of planetary systems. This particular disc is seen nearly edge-on, and its appearance in visible light pictures has led to its being nicknamed the Flying Saucer.

 

The astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the glow coming from carbon monoxide molecules in the 2MASS J16281370-2431391 disc. They were able to create very sharp images and found something strange -- in some cases they saw a negative signal! Normally a negative signal is physically impossible, but in this case there is an explanation, which leads to a surprising conclusion.

 

Lead author Stephane Guilloteau takes up the story: "This disc is not observed against a black and empty night sky. Instead it's seen in silhouette in front of the glow of the Rho Ophiuchi Nebula. This diffuse glow is too extended to be detected by ALMA, but the disc absorbs it. The resulting negative signal means that parts of the disc are colder than the background. The Earth is quite literally in the shadow of the Flying Saucer!"

 

The team combined the ALMA measurements of the disc with observations of the background glow made with the IRAM 30-metre telescope in Spain [1]. They derived a disc dust grain temperature of only -266 degrees Celsius (only 7 degrees above absolute zero, or 7 Kelvin) at a distance of about 15 billion kilometres from the central star [2]. This is the first direct measurement of the temperature of large grains (with sizes of about one millimetre) in such objects.

 

This temperature is much lower than the -258 to -253 degrees Celsius (15 to 20 Kelvin) that most current models predict. To resolve the discrepancy, the large dust grains must have different properties than those currently assumed, to allow them to cool down to such low temperatures.

 

"To work out the impact of this discovery on disc structure, we have to find what plausible dust properties can result in such low temperatures. We have a few ideas -- for example the temperature may depend on grain size, with the bigger grains cooler than the smaller ones. But it is too early to be sure," adds co-author Emmanuel di Folco (Laboratoire d'Astrophysique de Bordeaux).

 

If these low dust temperatures are found to be a normal feature of protoplanetary discs this may have many consequences for understanding how they form and evolve.

 

For example, different dust properties will affect what happens when these particles collide, and thus their role in providing the seeds for planet formation. Whether the required change in dust properties is significant or not in this respect cannot yet be assessed.

 

Low dust temperatures can also have a major impact for the smaller dusty discs that are known to exist. If these discs are composed of mostly larger, but cooler, grains than is currently supposed, this would mean that these compact discs can be arbitrarily massive, so could still form giant planets comparatively close to the central star.

 

Further observations are needed, but it seems that the cooler dust found by ALMA may have significant consequences for the understanding of protoplanetary discs.

 

Notes

[1] The IRAM measurements were needed as ALMA itself was not sensitive to the extended signal from the background.

[2] This corresponds to one hundred times the distance from the Earth to the Sun. This region is now occupied by the Kuiper Belt within the Solar System.

More information

This research was presented in a paper entitled "The shadow of the Flying Saucer: A very low temperature for large dust grains", by S. Guilloteau et al., published in Astronomy & Astrophysics Letters.

http://spaceref.com/astronomy/alma-finds-unexpectedly-cold-grains-in-planet-forming-disc.html

 

I could just imagine the look on their faces when the  ( -ve)  temperature was encountered...followed by..."mmmm......that's weird!"

 

:D

  • Like 2

Share this post


Link to post
Share on other sites
Draggendrop    5,747

James Webb Space Telescope Primary Mirror Fully Assembled

 

oo16-013b.thumb.jpg.0d99dca4fd522ba9ad9c

Webb Space Telescope Mirrors      NASA

 

Quote

The 18th and final primary mirror segment is installed on what will be the biggest and most powerful space telescope ever launched.

 

The final mirror installation Wednesday at NASA's Goddard Space Flight Center in Greenbelt, Maryland marks an important milestone in the assembly of the agency's James Webb Space Telescope.

 

"Scientists and engineers have been working tirelessly to install these incredible, nearly perfect mirrors that will focus light from previously hidden realms of planetary atmospheres, star forming regions and the very beginnings of the Universe," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington. "With the mirrors finally complete, we are one step closer to the audacious observations that will unravel the mysteries of the Universe."

 

Using a robotic arm reminiscent of a claw machine, the team meticulously installed all of Webb's primary mirror segments onto the telescope structure. Each of the hexagonal-shaped mirror segments measures just over 4.2 feet (1.3 meters) across -- about the size of a coffee table -- and weighs approximately 88 pounds (40 kilograms). Once in space and fully deployed, the 18 primary mirror segments will work together as one large 21.3-foot diameter (6.5-meter) mirror.

 

"Completing the assembly of the primary mirror is a very significant milestone and the culmination of over a decade of design, manufacturing, testing and now assembly of the primary mirror system," said Lee Feinberg, optical telescope element manager at Goddard. "There is a huge team across the country who contributed to this achievement."

 

While the primary mirror installation may be finished on the tennis court-sized infrared observatory, there still is much work to be done.

"Now that the mirror is complete, we look forward to installing the other optics and conducting tests on all the components to make sure the telescope can withstand a rocket launch," said Bill Ochs, James Webb Space Telescope project manager. "This is a great way to start 2016!"

 

The mirrors were built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and optical system design. The installation of the mirrors onto the telescope structure is performed by Harris Corporation, a subcontractor to Northrop Grumman. Harris Corporation leads integration and testing for the telescope.

 

"The Harris team will be installing the aft optics assembly and the secondary mirror in order to finish the actual telescope," said Gary Matthews, director of Universe Exploration at Harris Corporation. "The heart of the telescope, the Integrated Science Instrument Module, will then be integrated into the telescope. After acoustic, vibration, and other tests at Goddard, we will ship the system down to Johnson Space Center in Houston for an intensive cryogenic optical test to ensure everything is working properly."

 

The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb will study many phases in the history of our universe, including the formation of solar systems capable of supporting life on planets similar to Earth, as well as the evolution of our own solar system. It's targeted to launch from French Guiana aboard an Ariane 5 rocket in 2018. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

more at the link...

http://spaceref.com/james-webb-space-telescope/james-webb-space-telescope-primary-mirror-fully-assembled.html

 

Watch it being built on their webcam.... has a 1 minute image refresh rate, not real time....

http://www.jwst.nasa.gov/webcam.html

 

-----------------------------

 

A Tale of Galactic Merger

 

oofig1le.thumb.jpg.8ac68662bcfc20f090a88

NGC 6240          SUBARU TELESCOPE

 

Quote

An international team led by a researcher from Hiroshima University has succeeded in revealing the detailed structure of a massive ionized gas outflow streaming from the starburst galaxy NGC 6240.

 

The team used the Suprime-Cam mounted on the 8.2-meter Subaru Telescope on Maunakea in Hawaii.

 

The ionized gas the astronomers observed extends across 300,000 light-years and is carried out of the galaxy by a powerful superwind. That wind is driven by intense star-forming activity at the galactic center. The light-collecting power and high spatial resolution of Subaru Telescope made it possible to study, for the first time, the complex structure of one of the largest known superwinds being driven by starbirth -- and star death.

 

Starbursts and the Evolution of Galaxies

 

The term "starburst" indicates large-scale intensive star-forming activity, making a "starburst galaxy" one where starbirth is occurring on a grand scale. The star formation rate (SFR) of our Milky Way Galaxy is approximately one solar mass per year. By contrast, the SFRs of starburst galaxies reach ten, or even a hundred to a thousand solar masses per year.

 

Starburst activity is a very important part of galaxy evolution. When a starburst occurs, the intense episode of star formation rapidly consumes the galaxy's interstellar gas. In addition, ultraviolet light from newborn massive stars as well as gas heating and ram pressure from supernova explosions blows much of a galaxy's gas away into intergalactic space. This galactic-scale energetic wind is called a "galactic wind" or "superwind." Its action forces interstellar gas out of the galaxy very efficiently, which accelerates the galaxy's gas-loss rate. It also chokes off star formation.

 

The metal-rich gas expelled from the galaxy's disk pollutes its halo as well as intergalactic space. Consequently, a starburst and starburst-driven superwind significantly affect the evolution of the galaxy and the gas outside of that galaxy.

 

One of the mechanisms that seems to induce large-scale starburst activity is galaxy collision and merger. When two gas-rich giant spiral galaxies merge, the gravitational perturbation induced by the merging process disturbs the orbits of their stars. At the same time, the gas in the galaxy disks loses its angular momentum via viscous processes associated with gas mixing and falls into the gravitational center of the merger. This creates a vast concentration of gas, which begins to coalesce, creating a starburst knot. The starburst also creates a huge amount of dust which emits strong infrared radiation as it absorbs ultraviolet light from the newly born massive stars.

more at the link....

http://spaceref.com/astronomy/a-tale-of-galactic-merger.html

 

:D

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.