Posted on by Tammy Plotner

Milky Way Shakes, Rattles and Rolls…

Three stages of the evolution of the galaxy simulation used to model the Milky Way. (Credit: AIP)

For decades astronomers have puzzled over the many details concerning the formation of the Milky Way Galaxy. Now a group of scientists headed by Ivan Minchev from the Leibniz Institute for Astrophysics Potsdam (AIP) have managed to retrace our galaxy’s formative periods with more detail than ever before. This newly published information has been gathered through careful observation of stars located near the Sun and points to a rather “moving” history.

To achieve these latest results, astronomers observed stars perpendicular to the galactic disc and their vertical motion. Just to shake things up, these stars also had their ages considered. Because it is nearly impossible to directly determine a star’s true age, they rattled the cage of chemical composition. Stars which show an increase in the ratio of magnesium to iron ([Mg/Fe]) appear to have a greater age. These determinations of stars close to the Sun were made with highly accurate information gathered by the RAdial Velocity Experiment (RAVE). According to previous findings, “the older a star is, the faster it moves up and down through the disc”. This no longer seemed to be true. Apparently the rules were broken by stars with the highest magnesium-to-iron ratios. Despite what astronomers thought would happen, they observed these particular stars slowing their roll… their vertical speed decreasing dramatically.

So what’s going on here? To help figure out these curious findings, the researchers turned to computer modeling. By running a simulation of the Milky Way’s evolutionary patterns, they were able to discern the origin of these older, slower stars. According to the simulation, they came to the conclusion that small galactic collisions might be responsible for the results they had directly observed.

Smashing into, or combining with, a smaller galaxy isn’t new to the Milky Way. It is widely accepted that our galaxy has been the receptor of galactic collisions many times during its course of history. Despite what might appear to be a very violent event, these incidents aren’t very good at shaking up the massive regions near the galactic center. However, they stir things up in the spiral arms! Here star formation is triggered and these stars move away from the core towards our galaxy’s outer edge – and near our Sun.

In a process known as “radial migration”, older stars, ones with high values of magnesium-to-iron ratio, are pushed outward and display low up-and-down velocities. Is this why the elderly, near-by stars have diminished vertical velocities? Were they forced from the galactic center by virtue of a collision event? Astronomers speculate this to be the best answer. By comparison, the differences in speed between stars born near the Sun and those forced away shows just how massive and how many merging galaxies once shook up the Milky Way.

Says AIP scientist Ivan Minchev: “Our results will enable us to trace the history of our home galaxy more accurately than ever before. By looking at the chemical composition of stars around us, and how fast they move, we can deduce the properties of satellite galaxies interacting with the Milky Way throughout its lifetime. This can lead to an improved understanding of how the Milky Way may have evolved into the galaxy we see today.”

Original Story Source: Leibniz Institute for Astrophysics Potsdam News Release. For further reading: A new stellar chemo-kinematic relation reveals the merger history of the Milky Way.

Posted on by Jason Major

Watch Gaia Go From Lab to Launch in Two Minutes

In the early pre-dawn hours on December 19, 2013, with a rumble and a roar, a Soyuz rocket blazed through the clouds above the jungle-lined coast of French Guiana, ferrying ESA’s long-awaited Gaia spacecraft into orbit and beginning its mission to map the stars of the Milky Way. The fascinating time-lapse video above from ESA shows the Gaia spacecraft inside the clean room unfurling like a flower during its sunshield deployment test, the transfer of the Soyuz from the assembly building to the pad, and then its ultimate fiery liftoff.

That’s a lot going on in two minutes! But once nestled safely in its L2 orbit 1.5 million kilometers out, Gaia will have over five years to complete its work… read more here.

Credit: ESA–S. Corvaja, M. Pedoussaut, 2013. Source: ESA

Posted on by David Dickinson

Chandra’s Verdict on the Demise of a Star: “Death by Black Hole”

A composite x-ray and optical image of a dwarf galaxy showing the x-ray transcient in the inset. Credit-CFHT (Optical), NASA/CXC/University of Alabama/GSCF/UMD/W.P. Maksym, D.Donato et al.

This week, astronomers announced the detection of a rare event, a star being torn to shreds by a massive black hole in the heart of a distant dwarf galaxy. The evidence was presented Wednesday January 8th at the ongoing 223rd meeting of the American Astronomical Society being held this week in Washington D.C.

Although other instances of the death of stars at the hands of black holes have been witnessed before, Chandra may have been the first to document an intermediate black hole at the heart of a dwarf galaxy “in the act”.

The results span observations carried out by the space-based Chandra X-ray observatory over a period spanning 1999 to 2005. The search is part of an archival study of observations, and revealed no further outbursts after 2005.

“We can’t see the star being torn apart by the black hole, but we can track what happens to the star’s remains,” said University of Alabama’s Peter Maksym in a recent press release. A comparison of with similar events seen in larger galaxies backs up the ruling of “death by black hole.”  A competing team led by Davide Donato also looked at archival data from Chandra and the Extreme Ultraviolet Explorer (EUVE), along with supplementary observations from the Canada-France-Hawaii Telescope to determine the brightness of the host galaxy, and gained similar results.

The dwarf galaxy in the Abell 1795 cluster that was observed has the name WINGS J134849.88+263557.5, or WINGS J1348 for short. The Abell 1795 cluster is about 800 million light years distant.

WINGS denotes the galaxy’s membership in the WIde-field Nearby Galaxy-cluster Survey, and the phone number-like designation is the galaxy’s position in the sky in right ascension and declination.

Like most galaxies associated with galaxy clusters, WINGS J1348 a dwarf galaxy probably smaller than our own satellite galaxy known as the Large Magellanic Cloud. The Abell 1795 cluster is located in the constellation Boötes, and WINGS J1348 has an extremely faint visual magnitude of +22.46.

Optical
An optical view of the Abell 1795 galaxy cluster. Credit- NASA/CFHT/D. Donato et al.

“Scientists have been searching for these intermediate mass black holes for decades,” NASA’s Davide Donato said in a recent press release “We have lots of evidence for small black holes and very big ones, but these medium-sized ones have been tough to pin down.”

Maksym notes in an interview with Universe Today that this isn’t the first detection of an intermediate-mass black hole, which are a class of black holes often dubbed the “mostly” missing link between stellar mass and super massive black holes.

The mass range for intermediate black holes is generally pegged at 100 to one million solar masses.

What makes the event witnessed by Chandra in WINGS J1348 special is that astronomers managed to capture a rare tidal flare, as opposed to a supermassive black hole in the core of an active galaxy.

A bright, long duration flare may be the first recorded event of a black hole destroying a star in a dwarf galaxy. The dwarf galaxy is located in the galaxy cluster Abell 1795, about 800 million light years from Earth. A composite image of the cluster shows Chandra data in blue and optical data from the Canada-France-Hawaii Telescope in red, green and blue. An inset centered on the dwarf galaxy shows Chandra data taken between before and after 2005. The X-ray flare provides evidence that a large black hole has pulled in debris from a star that was torn apart by tidal forces.
A closeup view of the bright, long duration flare witnessed by Chandra pre-2005. Credit- NASA/CXC/University of Alabama/W.P. Maksym et al.

“Most of the time, black holes eat very little, so they can hide very well,” Maksym said in the AAS meeting on Wednesday.

This discovery pushes the limits on what we know of intermediate black holes. By documenting an observed number of tidal flare events, it can be inferred that a number of inactive black holes must be lurking in galaxies as well. The predicted number of tidal events that occur also have implications for the eventual detection of gravity waves from said mergers.

And more examples of these types of X-ray flare events could be waiting to be uncovered in the Chandra data as well.

“Chandra has taken quite a few pictures over the past 13+ years, and collaborators and I have an ongoing program to look for more tidal flares,” Maksym told Universe Today. “We’ve found one other this way, from a larger galaxy, and hope to find more. Abell 1795 was a particularly good place to look because as a calibration source, there were tons of pictures.”

Use of Chandra data was also ideal for the study because its spatial resolution allowed researchers to pinpoint an individual galaxy in the cluster. Maksym also notes that while it’s hard to get follow-up observations of events based on archival data, future missions dedicated to X-ray astronomy with wider fields of view may be able to scour the skies looking for such tidal flaring events.

The NuSTAR satellite was the latest X-Ray observatory  to launch in 2012.  NASA’s Extreme Ultraviolet Explorer picked up a strong ultraviolet source in 1998 right around the time of the tidal flare event, and ESA’s XMM-Newton satellite may have detected the event in 2000 as well.

This was also one of the smallest galaxies ever observed to contain a black hole. Maksym noted in Wednesday’s press conference that an alternative explanation could be a super-massive black hole in a tiny galaxy that just “nibbled” on a passing star, but said that new data from the Gemini observatory does not support this.

“It would be like looking into a dog house and finding a large ogre crammed in there,” Maksym said at Wednesday’s press conference.

This discovery provides valuable insight into the nature of intermediate mass black holes and their formation and behavior. What other elusive cosmological beasties are lying in wait to be discovered in the archives?

Congrats to Maksym and teams on this exciting new discovery, and the witnessing of a rare celestial event!

 

Posted on by Nancy Atkinson

Space Telescopes Look Back 13.2 Billion Years and See Surprisingly Luminous Galaxies

NASA's Hubble Space Telescope and Spitzer Space Telescope joined forces to discover and characterize four unusually bright galaxies as they appeared more than 13 billion years ago, just 500 million years after the big bang. Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team.

What was the Universe like more than 13 billion years ago, just 500 million years after the big bang? New data from the Hubble and Spitzer space telescopes reveal some surprisingly bright galaxies that are about 10 to 20 times more luminous than anything seen previously in that epoch.

Garth Illingworth from the University of California, Santa Cruz said the discovery of these four bright galaxies came from combining the power of both telescopes, but these galaxies lie right at the limit of the telescopes’ capabilities.

“We’re actually reaching back 13.2 billion years through the life of the Universe — that’s 96% of the life of the Universe that we are looking back at these galaxies,” said Illingworth, speaking at the American Astronomical Society meeting in Washington D.C. this week. “That’s an astonishing undertaking and an astonishing accomplishment that Hubble and Spitzer have achieved.”

Detail of the Hubble and Spitzer observations of a galaxy from the early Universe. Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team.
Detail of the Hubble and Spitzer observations of a galaxy from the early Universe. Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team.

Illingworth said the typical galaxy candidate from that far back in time is very faint and hard to see. But these new galaxies are about 15-20 % brighter than what astronomers have seen before at redshift 10.

The tiny are bright because they are bursting with star formation activity. The brightest one is forming stars approximately 50 times faster than the Milky Way does today. Although these fledgling galaxies are only one-twentieth the size of the Milky Way, they probably contain around a billion stars crammed together.

Astronomers think these bright, young galaxies grew exceptionally fast because of interactions and mergers of smaller infant galaxies that started forming stars even earlier in the Universe. Since the ancient time billions of years ago when the light that we now see started its long journey to us, they have probably kept growing to become similar to the largest modern galaxies. Many of the stars of these infant galaxies likely live on today in the centers of giant elliptical galaxies, much larger even than our own Milky Way.

Slide from Garth Illingworth's presentation at the 223rd American Astronomical Society meeting, describing the discovery of bright galaxies from early in the Universe. Credit: Garth Illingworth.
Slide from Garth Illingworth’s presentation at the 223rd American Astronomical Society meeting, describing the discovery of bright galaxies from early in the Universe. Credit: Garth Illingworth.

Illingworth said this era appears to be a timeframe where things were changing quite rapidly. “We’ve gone back to a very interesting time when the Universe is changing,” he said.

The galaxies were first detected with Hubble, and astronomers were able to measure their star-formation rates and sizes. But using Spitzer, the scientists were also able to measure the galaxies’ masses.

“This is the first-ever measurement of the mass density of the galaxies when the Universe was at 500 million years of age,” Illingworth said. “These galaxies are about a billion times the mass of our Sun, which is massive for those times, but still only 1% the mass of the Milky Way.”

Illingworth added that the mass measurements are rough estimates because of how challenging the task was.

Illingworth and team member Ivo Labbé from Leiden University said they are looking forward to finding out more about these galaxies, particularly from future observations with the upcoming James Webb Space Telescope.

“At the same time, the extreme masses and star formation rates are really mysterious,” Labbé said, “and we are eager to confirm them with future observations on our powerful telescopes.”

You can find out more about these early galaxies — and more — at the First Galaxies website.

Further reading: HubbleSite

Posted on by Elizabeth Howell

New Project Aims To Improve Galaxy Simulation — And Help Us Understand More About The Universe

Image of NGC 6872 (left) and companion galaxy IC 4970 (right) locked in a tango as the two galaxies gravitationally interact. The galaxies lie about 200 million light-years away in the direction of the constellation Pavo (the Peacock). Image credit: Sydney Girls High School Astronomy Club, Travis Rector (University of Alaska, Anchorage), Ángel López-Sánchez (Australian Astronomical Observatory/Macquarie University), and the Australian Gemini Office.

Galaxy modelling is complicated, and even more so when different computer models don’t agree on how the factors come together. This makes it hard to understand the nature of our universe. One new project called AGORA (Assembling Galaxies of Resolved Anatomy) aims to resolve the discrepancies and make the results more consistent. Basically, the project aims to compare different codes against each other and also against observations.

“The physics of galaxy formation is extremely complicated, and the range of lengths, masses, and timescales that need to be simulated is immense,” stated Piero Madau, professor of astronomy and astrophysics at the University of California, Santa Cruz and co-chair of the AGORA steering committee.

“You incorporate gravity, solve the equations of hydrodynamics, and include prescriptions for gas cooling, star formation, and energy injection from supernovae into the code. After months of number crunching on a powerful supercomputer, you look at the results and wonder if that is what nature is really doing or if some of the outcomes are actually artifacts of the particular numerical implementation you used.”

This is especially important when it comes to modelling the effect of dark matter on the universe. Since the entity is hard for us to see and therefore to identify, physicists rely on models to make predictions about its effect on galaxies and other forms of more ordinary matter.

Nine codes, nine galaxy formation scenarios: this is the sort of problem that AGORA is devoting itself to resolving by comparing different supercomputer simulations. Credit: Simulations performed by Samuel Leitner (ART-II), Ji-hoon Kim (ENZO), Oliver Hahn (GADGET-2- CFS), Keita Todoroki (GADGET-3), Alexander Hobbs (GADGET-3-CFS and GADGET-3-AFS), Sijing Shen (GASOLINE), Michael Kuhlen (PKDGRAV-2), and Romain Teyssier (RAMSES)
Nine codes, nine galaxy formation scenarios: this is the sort of problem that AGORA is devoting itself to resolving by comparing different supercomputer simulations.
Credit: Simulations performed by Samuel Leitner (ART-II), Ji-hoon Kim (ENZO), Oliver Hahn (GADGET-2- CFS), Keita Todoroki (GADGET-3), Alexander Hobbs (GADGET-3-CFS and GADGET-3-AFS), Sijing Shen (GASOLINE), Michael Kuhlen (PKDGRAV-2), and Romain Teyssier (RAMSES)

“One big challenge, however, has been numerically modeling astrophysical processes over the vast range of size scales in the Universe. Supercomputer simulations are designed with three different size scales relevant to three different phenomena: star formation, galaxy formation, and the large scale structure of the universe,” stated the University of California High-Performance Astrocomputing Center.

This means that models of stars coming to be inside of galaxies have one scale of resolution — enough to look at what the gas and dust is made of, for example — but when looking at the entire universe, the computer is more limited to looking at “simple gravitational interactions of dark matter”, the university added. Of course, the more resolution you can get in a computer model, the better — especially because star formation is affected by processes such as how galaxies interact with surrounding gas.

AGORA’s will first aim to “model a realistic isolated disk galaxy” UCSC states, and then compare the codes used to see what they come up with. You can read more about the project’s aims at this Arxiv pre-print paper (led by the University of California, Santa Cruz’s Ji-hoon Kim) or on the AGORA website.

Sources: University of California Santa Cruz and University of California High-Performance Astrocomputing Center.

Posted on by Tammy Plotner

Mapping Molecular Clouds Changes Astronomers Outlook On Starbirth

Molecular hydrogen in the Whirlpool Galaxy M51. The blueish features show the distribution of hydrogen molecules in M51, the raw material for forming new stars. The PAWS team has used this data to create a catalogue of more then 1,500 molecular clouds. The background is a color image of M51 by the Hubble Space Telescope. Superimposed in blue is the CO(1-0) radiation emitted by carbon monoxide (CO) molecules, as measured for the PAWS study using the millimeter telescopes of the Institut de Radioastronomie Millimétrique. The CO molecules are used as tracers for molecular hydrogen. Credit: PAWS team/IRAM/NASA HST/T. A. Rector (University of Alaska Anchorage)

It didn’t happen overnight. By studying the properties of giant molecular clouds in the Whirlpool Galaxy for several years with the millimeter telescopes of IRAM, the Institut de Radioastronomie Millimétrique, astronomers have been given a whole, new look at star formation. Encompassing 1,500 maps of molecular clouds, this new research has found these building blocks of future suns to be encased in a sort of molecular hydrogen mist. This ethereal mixture appears to be far denser than speculated and is found throughout the galactic disc. What’s more, it would appear the pressure created by the molecular fog is a critical factor in determining whether or not stars are able to form within the clouds.

Stars form in the molecular clouds housed within all galaxies. These formations are vast areas of hydrogen molecules with masses which total from a thousand to several million times that of the Sun. When an area of the cloud folds under the weight of its own gravity, it collapses. Pressure and temperature rise and nuclear fusion begins. A star is born.

This exciting new research is changing the way astronomers think about starbirth regions. Study leader Eva Schinnerer (Max Planck Institute for Astronomy) explains: “Over the past four years, we have created the most complete map yet of giant molecular clouds in another spiral galaxy similar to our own Milky Way, reconstructing the amounts of hydrogen molecules and correlating them with the presence of new or older stars. The picture that is emerging is quite different from what astronomers thought these clouds should be like.” The survey, known as PAWS, targeted the Whirlpool galaxy, also known as M51, at a distance of about 23 million light-years in the constellation Canes Venatici – the Hunting Dogs.

Annie Hughes, a post-doctoral researcher at MPIA involved in the study, says: “We used to think of giant molecular clouds as solitary objects, drifting within the surrounding interstellar medium of rarified gas in isolated splendor; the main repository of a galaxy’s supply of hydrogen molecules. But our study shows that 50% of the hydrogen is outside the clouds, in a diffuse, disk-shaped hydrogen fog permeating the galaxy!”

Not only does the enveloping gas play a critical part in star formation, but galaxy structure does as well. One galactic feature in particular is key – spiral arm structure. They sweep slowly around the core area like hands on a clock and are more populated with stars than the remainder of the galactic disk. Sharon Meidt, another MPIA post-doctoral researcher involved in the study, says: “These clouds are definitely not isolated. On the contrary, interactions between clouds, fog, and overall galactic structure appear to hold the key to whether or not a cloud will form new stars. When the molecular fog moves relative to the galaxy’s spiral arms, the pressure it exerts on any clouds within is reduced, in line with a physical law known as Bernoulli’s principle. Clouds feeling this reduced pressure are unlikely to form new stars. According to the press release, Bernoulli’s law is also thought to be responsible for part of the well-known shower-curtain effect: shower curtains blowing inward when one takes a hot shower, another display of reduced pressure.

Jerome Pety of the Institut de Radioastronomie Millimétrique (IRAM), which operates the telescopes used for the new observations, says: “It’s good to see our telescopes live up to their full potential. A study that needed such extensive observation time, and required both an interferometer to discern vital details and our 30 m antenna to put those details into a larger context, would not have been possible at any other observatory.”

Schinnerer concludes: “So far, the Whirlpool galaxy is one example which we have studied in depth. Next, we need to check that what we have found also applies to other galaxies. For our next steps, we hope to profit from both the extension NOEMA of the compound telescope on the Plateau de Bure and from the newly opened compound telescope ALMA in Chile, which will allow in-depth studies of more distant spiral galaxies.”

Original Story Source: Max Planck Institute for Astronomy News Release.

Posted on by Jason Major

Little Big Universe: Tilt-Shifted Astro Images Make Space Look Tiny

Hubble image of the Horsehead Nebula, "tilt-shifted" by Imgur user ScienceLlama (Original image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA))

Aww, how cute! What an adorable little… nebula?

Although here it may look like it could fit in your hand, the Horsehead Nebula is obviously quite a bit larger – about 1.5 light-years across from “nose” to “mane.” But given a tilt-shift effect by Imgur.com user ScienceLlama, the entire structure takes on the appearance of something tiny — based purely on our eyes’ natural depth-of-field when peering at a small object close up. Usually done with Photoshop filters these days, it’s a gimmick, yes… but it works!

The original image was captured in infrared light by the Hubble Space Telescope and released in April 2013, in celebration of its 23rd anniversary.

Check out more of ScienceLlama’s “tiny universe” images below:

A tiny Centaurus A
A tiny Centaurus A
A tiny Crab Nebula (see original Spitzer image here)
A tiny Crab Nebula (see original NASA image here)
A tiny Andromeda Galaxy (see original here)
A tiny Andromeda Galaxy in hydrogen alpha (see original here)

See these and more on ScienceLlama’s Imgur page here, and follow Science Llama on Twitter here.

(H/T to Google+ user Brian Koberlein and fellow Space Community member Warren Isaac. Featured on Reddit.com.)

ADDITION 12/17: Several of these images (like this one) were originally processed by Robert Gendler from Hubble-acquired data, but the attribution was not noted by ScienceLlama. I apologize for the oversight — see more of Robert’s beautiful astrophotography on his website here. Another original source was Adam Block of the Mount Lemmon Sky Center.

Posted on by Tammy Plotner

Subaru Telescope Reveals Orderly Massive Galaxy Evolution

FMOS spectra in the J-band (left panel) and H-band (right panel), each of which filters light so that only specific wavelengths can pass through. The horizontal axis refers to the wavelength direction while the vertical axis indicates individual spectra observed through each fiber. Small blue circles indicate the detection of emission lines (left: H? and [OIII]; right: H?, [NII]). The inset box shows the intensity of the emission lines for one galaxy. The vertical bands indicate the masked regions where bright sky (OH) emissions are prevented from entering science fibers placed on high-redshift galaxies. (Credit: FMOS-COSMOS)

Nobody likes a sloppy COSMOS (Cosmological Evolution Survey) and astronomers utilizing the Fiber-Multi-Object Spectrograph (FMOS) mounted on the Subaru Telescope have put order into chaos through their studies. The survey has found that some nine billion years ago galaxies were capable of producing new stars in a fashion as orderly as game of checkers. Despite their young cosmological age, the galaxies show signs containing high amounts of dust enriched by heavier elements – a mature state.

“These findings center on a major question: What was the universe like when it was maximally forming its stars?” says John Silverman, the principal investigator of the FMOS-COSMOS project at the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU).

These “universal” questions are just what the COSMOS team seeks to answer. Their research goals are to enlighten the scales of cosmic time in relationship with the environment, formation and evolution of massive galactic structures. When studying individual galaxies, they may be able to tell if their rate of growth can be attributed to large-scale environments. Information of this type can clarify what factors the early Universe structure may have contributed to the current form of local galaxies. One of the data sets the team is focusing on is using the FMOS on the Subaru Telescope to chart out the distribution of more than a thousand galaxies which formed over nine billion years ago – a time when the Universe was hitting its star-formation peak.

“One key to generating fruitful results is collaboration between COSMOS researchers to maximize optimal use of FMOS.” Silverman continues, “In this project, researchers from Kavli IPMU in Japan and the Institute for Astronomy at the University of Hawaii (principal investigator: David Sanders) formed an effective collaboration to implement their goal.” The observations spanned 10 clear nights starting in March 2012.

Why choose spectroscopy? This advanced fiber optics technology speaks for itself, collecting light over an area of sky equal in size to that of the Moon. The FMOS focuses on the near-infrared, filtering out unwanted emissions caused by warm temperatures and can acquire spectra from 400 galaxies simultaneously with a wide field of coverage of 30 arc minutes at prime-focus. By employing such a wide field of view, astronomers can squeeze in a wide range of objects in their local environments. This enables researchers to maximize information on star-forming regions, cluster formation, and cosmology.

As David Sanders, the principal investigator of the FMOS-COSMOS project at IfA, puts it, “FMOS has clearly revolutionized our ability to study how galaxies form and evolve across cosmic time. It is currently the most powerful instrument we have to study the large numbers of objects needed to understand galaxies of all sizes, shapes and masses — from the largest ellipticals to the smallest dwarfs. We are extremely fortunate that the Kavli IPMU-IfA collaboration is giving us this unique opportunity to study the distant universe in such exquisite detail.”

FMOS will soon be famous by revealing its true potential. It has been collecting copious amounts of data in a high spectral resolution mode and at a very successful rate. So far it has accomplished nearly half of its goal – to examine over a thousand galaxies with redshifts to map the large-scale structure. The current survey consists of mapping an area of sky which spans a square degree in high-resolution mode and future plans for FMOS will involve enlarging the area. This expanded coverage will complement other instruments on alternative telescopes which have a wider spectral imaging system or a higher resolution which is limited to a smaller area. These combined findings may one day result in showing us some of the very first structures that eventually evolved into the massive galaxy clusters we see today!

Original Story Source: Kavli Institute for the Physics and Mathematics of the Universe News Release.

Posted on by Elizabeth Howell

Galaxy May Host ‘Death Spiral’ Of Two Black Holes Becoming One

Artist's conception of two black holes gravitationally bound to each other. Credit: NASA

Two black holes in the middle of a galaxy are gravitationally bound to each other and may be starting to merge, according to a new study.

Astronomers came to that conclusion after studying puzzling behavior in what is known as WISE J233237.05-505643.5, a discovery that came from NASA’s Wide-field Infrared Survey Explorer (WISE). Follow-up studies came from the Australian Telescope Compact Array and the Gemini South telescope in Chile.

“We think the jet of one black hole is being wiggled by the other, like a dance with ribbons,” stated research leader Chao-Wei Tsai of NASA’s Jet Propulsion Laboratory. “If so, it is likely the two black holes are fairly close and gravitationally entwined.”

“The dance of these black hole duos starts out slowly, with the objects circling each other at a distance of about a few thousand light-years,’ NASA added in a press release. “So far, only a few handfuls of supermassive black holes have been conclusively identified in this early phase of merging. As the black holes continue to spiral in toward each other, they get closer, separated by just a few light-years. ”

You can read more details of the find at a press release here, or at this Arxiv paper.

Posted on by Jason Major

Astronomers Catch a Galactic Threesome in the Act

A combined image from the Spitzer, Hubble, and Subaru telescopes show this structure to be three galaxies merging into one (NASA/JPL-Caltech/STScI/NAOJ/Subaru)

An enormous and incredibly luminous distant galaxy has turned out to actually be three galaxies in the process of merging together, based on the latest observations from ALMA as well as the Hubble and Spitzer space telescopes. Located 13 billion light-years away, this galactic threesome is being seen near the very beginning of what astronomers call the “Cosmic Dawn,” a time when the Universe first became illuminated by stars.

“This exceedingly rare triple system, seen when the Universe was only 800 million years old, provides important insights into the earliest stages of galaxy formation during a period known as ‘Cosmic Dawn’ when the Universe was first bathed in starlight,” said Richard Ellis, professor of astronomy at Caltech and member of the research team. “Even more interesting, these galaxies appear poised to merge into a single massive galaxy, which could eventually evolve into something akin to the Milky Way.”

In the image above, infrared data from NASA’s Spitzer Space Telescope are shown in red, visible data from NASA’s Hubble Space Telescope are green, and ultraviolet data from Japan’s Subaru telescope are blue. First discovered in 2009, the object is named “Himiko” after a legendary queen of Japan.

The merging galaxies within Himiko are surrounded by a vast cloud of hydrogen and helium, glowing brightly from the galaxies’ powerful outpouring of energy.

What’s particularly intriguing to astronomers is the noted lack of heavier elements like carbon in the cloud.

“This suggests that the gas cloud around the galaxy is actually quite primitive in its composition,” Ellis states in an NRAO video, “and has not yet been enriched by the products of nuclear fusion in the stars in the triple galaxy system. And what this implies is that the system is much younger and potentially what we call primeval… a first-generation object that is being seen. If true that’s very very exciting.”

Further research of distant objects like Himiko with the new high-resolution capabilities of ALMA will help astronomers determine how the Universe’s first galaxies “turned on”… was it a relatively sudden event, or did it occur gradually over many millions of years?

Watch the full video from the National Radio Astronomy Observatory below:

The research team’s results have been accepted for publication in the Astrophysical Journal.

Source: NASA/JPL press release and the NRAO.