Nearby Stream of Stars Reveals Past Cosmic Collision

The 51st entry in Charles Messier's famous catalog is perhaps the original spiral nebula--a large galaxy with a well defined spiral structure also cataloged as NGC 5194. Over 60,000 light-years across, M51's spiral arms and dust lanes clearly sweep in front of its companion galaxy, NGC 5195. Image data from the Hubble's Advanced Camera for Surveys was reprocessed to produce this alternative portrait of the well-known interacting galaxy pair. The processing sharpened details and enhanced color and contrast in otherwise faint areas, bringing out dust lanes and extended streams that cross the small companion, along with features in the surroundings and core of M51 itself. The pair are about 31 million light-years distant. Not far on the sky from the handle of the Big Dipper, they officially lie within the boundaries of the small constellation Canes Venatici. Image Credit: NASA

The tangled remains of vast cosmic collisions can be seen across the universe, such as the distant Whirlpool Galaxy’s past close encounter with a nearby galaxy, which resulted in the staggering beauty we see today.

Such colossal collisions between galaxies appear to be common. It’s likely giant galaxies, such as our own, originated long ago after smaller dwarf galaxies crashed together. Unfortunately, Hubble has yet to peer into the early Universe and catch two dwarf galaxies merging by chance. And they’re extremely rare to catch in the present nearby universe.

But for the first time, astronomers have uncovered evidence of a similar collision much closer to home.

The Milky Way is part of a large cosmic neighborhood. A collection of more than 35 galaxies compose the Local Group. While the largest and heavier members are the Milky Way and the Andromeda galaxy, there are many smaller satellite galaxies orbiting the two.  Anyone who has looked at the southern sky should be familiar with the Large and Small Magellanic Clouds: two satellite galaxies of the Milky Way less than 200,000 light years away.

Andromeda has over 20 satellite galaxies circling its nearly a trillion stars. A team of European astronomers has analyzed measurements of the stars in the dwarf galaxy Andromeda II — the second largest dwarf galaxy in the Local Group — and made a surprising discovery: an odd stream of stars that simply doesn’t belong.

The team led by Dr. Nicola C. Amorisco from the Dark Cosmology Centre at the Niels Bohr Institute in Copenhagen used the Deep Imaging Multi-Object (DEIMOS) spectrograph onboard the Keck II telescope in Hawaii in order to measure the velocities of more than 700 stars in the Andromeda II dwarf galaxy.

Stars in a large spiral galaxy will move, on average, with the rotation of the galaxy. On one side of the galaxy’s spinning disk, the stars will be moving away from the Earth, and their light waves will be stretched to redder wavelengths. On the opposite side, the stars will be moving toward the Earth, and their light waves will be compressed to bluer wavelengths.

But the stars in dwarf galaxies don’t exhibit such a pattern. Instead they move around entirely at random.

Amorisco and colleagues, however, found a rather different case present in Andromeda II. They observed a stream of stars — roughly 16,000 light years in length and 980 light years in thickness — that didn’t exhibit random motions at all. They orbit the center of the galaxy in a very coherent fashion.

But it gets better: the stars in this stream are also much colder than the stars outside the stream. In astronomy this is the equivalent of saying that the stars in this stream are much older. Amorisco’s team now believes they once belonged to a different galaxy entirely and remain only as a remnant of the past collision, which likely occurred over 3 billion years ago.

Streams of stars often result from collisions. As two galaxies begin to interact, the stars nearest the approaching galaxy feel a much stronger gravitational pull than the stars further away. Eventually the gravitational pull on the closer side of the galaxy will pull the stars from their initial galaxy, creating a stream of stars, dust and gas.

This is the smallest known example of two galaxies merging. The finding adds further evidence that mergers between dwarf galaxies plays a fundamental role in creating the large and beautiful galaxies we see today.

The paper has been published in Nature and is available for download here.

Pushy Black Holes Stop Elliptical Galaxies From Forming Stars

Multi-wavelength view of the elliptical galaxy NGC 5044. Credit: Digitised Sky Survey/NASA Chandra/Southern Observatory for Astrophysical Research/Very Large Array (Robert Dunn et al. 2010)

Contradicting past theories, cold gas has been found in abundance in some elliptical galaxies — showing that there must be some other explanation why these types of galaxies don’t form new stars. Astronomers believe that the jets from supermassive black holes in these galaxies’ center must push around the gas and prevent stars from forming.

Researchers spotted the gas for the first time using old data from the recently retired Herschel space observatory, which was able to peer well into the infrared — where it spotted carbon ions and oxygen atoms. This find stands against the previous belief that these galaxies were “red and dead”, referring to their physical appearance and the fact that they form no new stars.

“We looked at eight giant elliptical galaxies that nobody had looked at with Herschel before and we were delighted to find that, contrary to previous belief, six out of eight abound with cold gas”, stated Norbert Werner, a researcher at Stanford University in California who led the study.

“These galaxies are red, but with the giant black holes pumping in their hearts, they are definitely not dead,” added Werner.

NGC 1399, an elliptical galaxy about 65 million light years from Earth.  Credit: NASA, Chandra
NGC 1399, an elliptical galaxy about 65 million light years from Earth. Credit: NASA, Chandra

Previously, scientists thought that the galaxies got rid of their cold gas or had used it all up during a burst of earlier star formation. With cold gas found in the majority of the sample, researchers then used other observatories to try to find warmer gas up to tens of millions of Kelvin (or Fahrenheit or Celsius).

X-ray information from NASA’s Chandra X-ray Observatory revealed that there is hot gas cooling in six of the eight galaxies, but not in the remaining two of the sample.

“This is consistent with theoretical expectations: once cooled, the hot gas would become the warm and cold gas that are observed at longer wavelengths. However, in these galaxies the cooling process somehow stopped, and the cold gas failed to condense and form stars,” the European Space Agency stated.

“While the six galaxies with plenty of cold gas harbour moderately active black holes at their centres,” ESA added, “the other two show a marked difference. In the two galaxies without cold gas, the central black holes are accreting matter at frenzied pace, as confirmed by radio observations showing powerful jets of highly energetic particles that stem from their cores.”

You can read more about the research in the Monthly Notices of the Royal Astronomical Society or in preprint version on Arxiv.

Source: European Space Agency

‘Green Valley’ Of Galaxies Shows Off Gas And Star Formation

M33, the Triangulum Spiral Galaxy, seen here in a 4.3 hour exposure image. Astronomers used JWST to examine a section of its south spiral arm to search out and find nearly 800 newly forming stars. Credit and copyright: John Chumack.
M33, the Triangulum Spiral Galaxy, seen here in a 4.3 hour exposure image. Astronomers used JWST to examine a section of its south spiral arm to search out and find nearly 800 newly forming stars. Credit and copyright: John Chumack.

We keep saying this: the universe is more complex than it appears. Conventional thinking in galaxy research postulates that spiral galaxies have star-forming areas, while ellipticals do not due to a lack of gas. While this thinking has been debunked, there’s now emerging research showing a “green valley” of galaxies somewhat in between these two types.

Basically, the research (which includes participation from citizen scientists in the Galaxy Zoo project) is showing that there are two different populations of “green” galaxies, between ellipticals and spirals. Further, what happens to star formation based upon gas in the area.

“In this paper, we take a look at the most crucial event in the life of a galaxy: the end of star formation. We often call this process ‘quenching’ and many astrophysicists have slightly different definitions of quenching. Galaxies are the place where cosmic gas condenses and, if it gets cold and dense enough, turns into stars. The resulting stars are what we really see as traditional optical astronomers,” wrote Kevin Schawinski, a Ph.D. student at the University of Oxford who is on the Galaxy Zoo team, in a blog post.

“Not all stars shine the same way though: stars much more massive than our sun are very bright and shine in a blue light as they are very hot. They’re also very short-lived. Lower mass stars take a more leisurely pace and don’t shine as bright (they’re not as hot). This is why star-forming galaxies are blue, and quiescent galaxies (or ‘quenched’ galaxies) are red: once star formation stops, the bluest stars die first and aren’t replaced with new ones, so they leave behind only the longer-lived red stars for us to observe as the galaxy passively evolves.”

You can read more information in the blog post. The study, which has been accepted for publication in the Monthly Notices of the Royal Astronomical Society, is available on preprint site Arxiv.

Ghostly Cat’s Eye Nebula Shines In Space Telescope Calibration Image

A view of the Cat's Eye Nebula during the calibration phase of Gaia, a Milky Way-mapping telescope. Credit: ESA/DPAC/Airbus DS

Here’s a glimpse of how a telescope gets ready for its main mission. The European Space Agency’s Gaia telescope is in the middle of a commissioning phase before mapping out the locations of stars and other objects in the Milky Way. While the nominal mission is not to take pictures, it is through these images that controllers can verify that the telescope is tuned properly to do its work.

What you’re seeing is data from the Gaia camera’s “sky-mapper strips” that are actually intensity maps rendered in black and white, ESA explained. You can see in the picture above that the shot on the left is a bit blurry, while the one on the right looks a bit sharper. That’s because controllers better calibrated the charged coupled devices to the spacecraft’s spin rate, ESA said.

Lucky for us, ESA is sharing those images so we can see the process in action. This set of pictures below follows on from a calibration image of the Large Magellanic Cloud that was released last week. More details are available at ESA and also in this Dec. 19 Universe Today story.

A calibration image of M94 taken by Gaia, a Milky Way-mapping telescope, in early 2014. The gap is due to the image appearing on two separate CCDs. Credit: ESA/DPAC/Airbus DS
A calibration image of M94 taken by Gaia, a Milky Way-mapping telescope, in early 2014. The gap is due to the image appearing on two separate CCDs. Credit: ESA/DPAC/Airbus DS
Writes the European Space Agency in February 2014: "This is a rotated Gaia image section (left; extracted from the cluster image of NGC 2516 above), compared to a Digital Sky Survey image taken from the ground (right)." Credit: ESA/DPAC/Airbus DS/DSS
Writes the European Space Agency in February 2014: “This is a rotated Gaia image section (left; extracted from the cluster image of NGC 2516 above), compared to a Digital Sky Survey image taken from the ground (right).” Credit: ESA/DPAC/Airbus DS/DSS

Teamwork! Two Telescopes Combine Forces To Spot Distant Galaxy Clusters

Artist's impression of the Herschel Space Telescope. Credit: ESA/AOES Medialab/NASA/ESA/STScI
Artist's impression of the Herschel Space Telescope. Credit: ESA/AOES Medialab/NASA/ESA/STScI

Doing something extraordinary often requires teamwork for humans, and the same can be said for telescopes. Witness the success of the Herschel and Planck observatories, whose data was combined in such a way to spot four galaxy clusters 10 billion years away — an era when the universe was just getting started.

Now that they have the technique down, astronomers believe they’ll be able to find about 2,000 other distant clusters that could show us more about how these collections of galaxies first came together.

Although very far away, the huge clumps of gas and dust coming together into stars is still visible, allowing telescopes to see the process in action.

“What we believe we are seeing in these distant clusters are giant elliptical galaxies in the process of being formed,” stated David Clements, a physicist at Imperial College London who led the research, referring to one of the two kinds of galaxies the universe has today. Elliptical galaxies are dominated by stars that are already formed, while spiral galaxies (like the Milky Way) include much more gas and dust.

Three false-color images of Herschel images identified by Planck. Infrared light is represented in three colors -- blue, green, and red -- that respectively show longer wavelengths. The green circle shows where Planck aimed. The co-ordinates show the location in right ascension and declination. Credit: D. Clements/ESA/NASA
Three false-color images of Herschel images identified by Planck. Infrared light is represented in three colors — blue, green, and red — that respectively show longer wavelengths. The green circle shows where Planck aimed. The co-ordinates show the location in right ascension and declination. Credit: D. Clements/ESA/NASA

This finding is yet another example of how the data from telescopes lives on, and can be used, long after the telescope missions have finished. Both Planck and Herschel finished their operations last year.

“The researchers used Planck data to find sources of far-infrared emission in areas covered by the Herschel satellite, then cross-referenced with Herschel data to look at these sources more closely,” the Royal Astronomical Society stated.

The two telescopes had complementary views, with Planck looking at the entire sky while Herschel surveyed smaller sections in higher resolution. By combining the data, researchers found 16 sources in total. A dozen of them were already discovered single galaxies, but four were the newly discovered galaxy clusters. Fresh observations were then used to figure out the distance.

You can read more details in the Monthly Notices of the Royal Astronomical Society or in preprint version on Arxiv.

Source: Royal Astronomical Society

Greedy Galaxies Gobbled Gas, Stalling Star Formation Billions Of Years Ago

Arp 147 contains a spiral galaxy (right) that collided with an elliptical galaxy (left), triggering a wave of star formation. Credit: X-ray: NASA/CXC/MIT/S.Rappaport et al, Optical: NASA/STScI

Like millionaires that burn through their cash too quickly, astronomers have found one factor behind why compact elliptical galaxies stopped growing stars about 11 billion years ago: they ate through their gas reserves.

The revelation comes as researchers released a new evolutionary track for compact elliptical galaxies that stopped their star formation when the universe was just three billion years old. When these galaxies ran out of gas, some of them cannibalized smaller galaxies to create giant elliptical galaxies. The “burned-out”galaxies have stars crowding 10 to 100 times more densely than elliptical galaxies formed more recently through a different evolutionary track.

“We at last show how these compact galaxies can form, how it happened, and when it happened. This basically is the missing piece in the understanding of how the most massive galaxies formed, and how they evolved into the giant ellipticals of today,” stated Sune Toft, who led the study and is a researcher at the Dark Cosmology Center at the Niels Bohr Institute in Copenhagen.

“This had been a great mystery for many years, because just three billion years after the Big Bang we see that half of the most massive galaxies have already completed their star formation.”

How massive elliptical galaxies evolved in about 13 billion years. Credit: NASA, ESA, S. Toft (Niels Bohr Institute), and A. Feild (STScI)
How massive elliptical galaxies evolved in about 13 billion years. Credit: NASA, ESA, S. Toft (Niels Bohr Institute), and A. Feild (STScI)

The team got a snapshot of these galaxies’ evolution by looking at a representative sample with the Hubble Space Telescope, specifically through the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) and a spectroscopic survey called 3D-HST. To find out how old the stars were, they combined the Hubble work with data gathered from the  Spitzer Space Telescope and the Subaru Telescope in Hawaii.

Next, they examined ancient, fast-star-forming submillimeter galaxies with data gathered from a range of space and ground-based telescopes.

The Hubble Space Telescope. image credit: NASA, tweaked by D. Majaess.
The Hubble Space Telescope. image credit: NASA, tweaked by D. Majaess.

“This multi-spectral information, stretching from optical light through submillimeter wavelengths, yielded a full suite of information about the sizes, stellar masses, star-formation rates, dust content, and precise distances of the dust-enshrouded galaxies that were present early in the universe,” Hubble’s news center stated.

The group found that that the submillimeter galaxies were likely “progenitors” of compact elliptical galaxies, as they share predicted characteristics of the ancestors. Further, researchers calculated that starbursts in submillimeter galaxies only went on for about 40 million years before the galaxies ran out of gas.

You can read the results in the Feb. 20 edition of the Astrophysical Journal or in prepublished version in Arxiv.

Source: Hubble News Center

What Fuels The Engine Of A Supermassive Black Hole?

Orbiting near a moving black hole doesn't seem like the safest mode of transportation, but time dilation might make it worth the risk. Credit: NAOJ

If you could get a good look at the environment around a supermassive black hole — which is a black hole often found in the center of the galaxy — what factors would make that black hole keep going?

A Japanese study revealed that at least one of these black holes stay “active and luminous” by gobbling up nearby material, but notes that only a few of the observed galaxies that are merging have these types of black holes. This must mean something unique arises in the environment near the black hole to get it going, the researchers say. What that is, though, is still poorly understood.

Supermassive black holes, defined as black holes that have a million times the mass of the sun or more, reside in galaxy centers. “The merger of gas-rich galaxies with SMBHs [supermassive black holes] in their centers not only causes active star formation, but also stimulates mass accretion onto the existing SMBHs,” stated a press release from the Subaru Telescope.

“When material accretes onto a SMBH, the accretion disk surrounding the black hole becomes very hot from the release of gravitational energy, and it becomes very luminous. This process is referred to as active galactic nucleus (AGN) activity; it is different from the energy generation activity by nuclear fusion reactions within stars.”

Figuring out how these types of activity vary would give a clue as to how galaxies come together, the researchers said, but it’s hard to see anything in action because of dust and gas blocking the view of optical telescopes. That’s why infrared observations come in so handy, because it makes it easier to peer through the debris. (You can see some examples from this research below.)

Examples of infrared K-band images of luminous, gas-rich, merging galaxies. Credit: NAOJ
Examples of infrared K-band images of luminous, gas-rich, merging galaxies. Credit: NAOJ

The team (led by the  National Astronomical Observatory of Japan’s Masatoshi Imanishi) used NAOJ’s Subaru’s Infrared Camera and Spectrograph (IRCS) and the telescope’s adaptive optics system in two bands of infrared. Researchers looked at 29 luminous gas-rich merging galaxies in the infrared and found “at least” one active supermassive black hole in all but one of the ones studied.  However, only four of these galaxies merging had multiple, active black holes.

“The team’s results mean that not all SMBHs in gas-rich merging galaxies are actively mass accreting, and that multiple SMBHs may have considerably different mass accretion rates onto SMBHs,” Subaru stated.

The implication is more about the environment around a supermassive black hole must be understood to figure out how mass accretes. Knowing more about this will improve computer simulations of galaxy mergers, the researchers said.

You can read the published study in the Astrophysical Journal or in prepublished form on Arxiv.

Source: Subaru Telescope

“Vampire” Galaxy Sucks Star-Forming Gas from its Neighbors

The spiral galaxy NGC 6946 and its smaller companions are found to be surrounded by "cold rivers" of hydrogen

What happens when a galaxy doesn’t have enough hydrogen to support its stellar production process? Why, it sucks it from its hapless neighbors like some sort of cosmic vampire, that’s what. And evidence of this predatory process is what’s recently been observed with the National Science Foundation’s Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, in the form of faint “cold flows” bridging intergalactic space between the galaxy NGC 6946 and its smaller companions.

“We knew that the fuel for star formation had to come from somewhere,” said astronomer D.J. Pisano from West Virginia University, author of the study. “So far, however, we’ve detected only about 10 percent of what would be necessary to explain what we observe in many galaxies. A leading theory is that rivers of hydrogen – known as cold flows – may be ferrying hydrogen through intergalactic space, clandestinely fueling star formation. But this tenuous hydrogen has been simply too diffuse to detect, until now.”

NGC 6946 also goes by the festive moniker of “the Fireworks Galaxy,” due to the large amount of supernovae that have been observed within its arms — eight within the past century alone. Located 22 million light-years away between the constellations Cepheus and Cygnus, NGC 6946’s high rate of star formation has made astronomers curious as to how it (and other starburst galaxies like it) gets its stellar fuel.

One long-standing hypothesis is that large galaxies like NGC 6946 receive a constant supply of hydrogen gas by drawing it off their less-massive companions.

Chandra and Gemini image of NGC 6946 (X-ray: NASA/CXC/MSSL/R.Soria et al, Optical: AURA/Gemini OBs)
Chandra and Gemini image of NGC 6946 (X-ray: NASA/CXC/MSSL/R.Soria et al, Optical: AURA/Gemini OBs)

Now, thanks to the GBT’s unique capabilities — such as its immense single dish, unblocked aperture, and location in the National Radio Quiet Zone — direct observations have been made of the extremely faint radio emissions coming from neutral hydrogen flows connecting NGC 6946 with its smaller satellite galaxies.

According to a press release from the National Radio Astronomy Observatory:

Earlier studies of the galactic neighborhood around NGC 6946 with the Westerbork Synthesis Radio Telescope (WSRT) in the Netherlands have revealed an extended halo of hydrogen (a feature commonly seen in spiral galaxies, which may be formed by hydrogen ejected from the disk of the galaxy by intense star formation and supernova explosions). A cold flow, however, would be hydrogen from a completely different source: gas from intergalactic space that has never been heated to extreme temperatures by a galaxy’s star birth or supernova processes.

Another possible source of the cold flow is a previous collision with another galaxy, possibly even one of its own satellites, which would have left strands of atomic hydrogen in its wake. But if that were the case stars would likely have since formed within the filaments themselves, which has not yet been observed.

Pisano’s findings have been published in the Astronomical Journal.

Source: NRAO press release. Learn more about the Green Bank Telescope here.

Image credit: D.J. Pisano (WVU); B. Saxton (NRAO/AUI/NSF); Palomar Observatory – Space Telescope Science Institute 2nd Digital Sky Survey (Caltech); Westerbork Synthesis Radio Telescope

Cloudy Weather Led To ‘Fluke’ M82 Supernova Discovery

Images of M82 show the supernova after discovery, compared with an earlier image. Credit: UCL/University of London Observatory/Steve Fossey/Ben Cooke/Guy Pollack/Matthew Wilde/Thomas Wright

In a rare example of cloudy weather helping astronomy rather than hurting it, the team that found M82’s new supernova swung a telescope in that direction only because their planned targets for the night were obscured, a release stated.

The exploding star in the “Cigar Galaxy” was found at 7:20 p.m. UTC (2:20 p.m. EST) during a class taught by Steve Fossey at the University of London Observatory. Students Ben Cooke, Tom Wright, Matthew Wilde and Guy Pollack all participated in the discovery.

“The weather was closing in, with increasing cloud,”  recalled Fossey in a press release, “so instead of the planned practical astronomy class, I gave the students an introductory demonstration of how to use the CCD camera on one of the observatory’s automated 0.35–metre [1.14-foot] telescopes.”

The new supernova in M82 captured by the 32-inch Schulman Telescope (RCOS) at the Mount Lemmon Sky Center in Arizona on January 23, 2014. Credit and copyright: Adam Block/Mount Lemmon SkyCenter/University of Arizona
The new supernova in M82 captured by the 32-inch Schulman Telescope (RCOS) at the Mount Lemmon Sky Center in Arizona on January 23, 2014. Credit and copyright: Adam Block/Mount Lemmon SkyCenter/University of Arizona

The students asked for M82, at which point Fossey saw a star that he couldn’t recall from examining the galaxy previously. A search of other images online revealed that something strange was happening, but clouds were obscuring everything quickly. The team focused on taking one- and two-minute exposures with different filters, and also using a second telescope to make sure there wasn’t something wrong with the first.

The team checked for any reports of a supernova, and finding none, Fossey sent a message to the International Astronomical Union’s Central Bureau for Astronomical Telegrams (which catalogs supernovae) and a United States team that does regular searches for exploding stars. Among his concerns was that it could be an asteroid lying in the way of the galaxy, but further spectroscopic measurements confirmed the “fluke” find, the release added.

The great thing about SN 2014J is it’s visible even in small telescopes. It’s also fairly close, by astronomical standards, at about 12 million light-years away. (The closest found since the invention of the telescope was Supernova 1987A, which exploded in February 1987 and was 168,000 light-years away.) Astrophotographers have already snapped many images of the exploding star.

“One minute we’re eating pizza, then five minutes later we’ve helped to discover a supernova,” stated Wright. “I couldn’t believe it. It reminds me why I got interested in astronomy in the first place.”

Source: University College London

‘Cosmic Flashlight’ Makes Gas Glow Like A Fluorescent Light Bulb

A nebula (seen in cyan) that is about two million light-years across. It was found surrounding the bright quasar UM287 (center). Credit: S. Cantalupo (UCSC)

Funny how a single quasar can illuminate — literally and figuratively — some of the mysteries of the universe. From two million light-years away, astronomers spotted a quasar (likely a galaxy with a supermassive black hole in its center) shining on a nearby collection of gas or nebula. The result is likely showing off the filaments thought to connect galaxies in our universe, the team said.

“This is a very exceptional object: it’s huge, at least twice as large as any nebula detected before, and it extends well beyond the galactic environment of the quasar,” stated Sebastiano Cantalupo, a postdoctoral fellow at the University of California Santa Cruz who led the research.

The find illuminated by quasar UM287  could reveal more about how galaxies are connected with the rest of the “cosmic web” of matter, astronomers said. While these filaments were predicted in cosmological simulations, this is the first time they’ve been spotted in a telescope.

“Gravity causes ordinary matter to follow the distribution of dark matter, so filaments of diffuse, ionized gas are expected to trace a pattern similar to that seen in dark matter simulations,” UCSC stated.

A graphic showing how matter in the universe could be distributed. Some astronomers believe matter is sprinkled as a a "cosmic web" of filaments. The larger section shows a dark-matter simulation (by Anatoly Klypin and Joel Primack) and the inset a smaller portion, 10 million light-years across, from another simulation that also includes gas (S. Cantalupo).  Credit:  S. Cantalupo (UCSC), Joel Primack (UCSC) and Anatoly Klypin (NMSU).
A graphic showing how matter in the universe could be distributed. Some astronomers believe matter is sprinkled as a a “cosmic web” of filaments. The larger section shows a dark-matter simulation (by Anatoly Klypin and Joel Primack) and the inset a smaller portion, 10 million light-years across, from another simulation that also includes gas (S. Cantalupo). Credit: S. Cantalupo (UCSC), Joel Primack (UCSC) and Anatoly Klypin (NMSU).

Astronomers added that it was lucky that the quasar happened to be shining in the right direction to illuminate the gas, acting as a sort of “cosmic flashlight” that could show us more of the underlying matter. UM287 is making the gas glow in a similar way that fluorescent light bulbs behave on Earth, the team added.

“This quasar is illuminating diffuse gas on scales well beyond any we’ve seen before, giving us the first picture of extended gas between galaxies,” stated J. Xavier Prochaska, coauthor and professor of astronomy and astrophysics at UC Santa Cruz. “It provides a terrific insight into the overall structure of our universe.”

The find was made using the 10-meter Keck I telescope at the W. M. Keck Observatory in Hawaii. You can check out more details on the discovery on the Keck Observatory’s website or at this press release from the Max Planck Institute for Astronomy in Heidelberg, Germany.

The research was published in the Jan. 19 edition of Nature and available in preprint version on Arxiv.