The Mice

The Mice

This colliding pair of spiral galaxies is known as "The Mice" because of the long tails of stars and gas emanating from each galaxy. Otherwise known as NGC 4676, they will eventually merge into a single giant galaxy.

In the galaxy at left, the bright blue patch can be identified as a cascade of clusters and associations of young, hot blue stars, whose formation has been triggered by the tidal forces of the gravitational interaction. Streams of material can also be seen flowing between the two galaxies in this Hubble Space Telescope image.

The clumps of young stars in the long, straight tidal tail (upper right) are separated by fainter regions of material. These dim regions suggest that the clumps of stars have formed from the gravitational collapse of the gas and dust that once occupied those areas. Some of the clumps have luminous masses comparable to dwarf galaxies that orbit in the halo of our own Milky Way.

For more information, visit: hubblesite.org/image/1183/news_release/2002-11

For a computer simulation of The Mice colliding, visit: hubblesite.org/video/285/news_release/2002-11

Credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA

Posted by NASA Hubble on 2019-04-09 20:57:37

Tagged: , NGC 4676 , Interacting galaxies , colliding galaxies , galaxy collision , galaxy , galaxies , space , astronomy , NASA , Hubble , Hubble Space Telescope , cosmos

Interacting Galaxy NGC 4485

Interacting Galaxy NGC 4485

Galaxy NGC 4485 is irregular in shape, but it hasn’t always been so. Part of NGC 4485 has been dragged toward a second galaxy, named NGC 4490 — which lies out of frame to the bottom right of this image. Between them, these two galaxies make up a galaxy pair called Arp 269. Their interactions have warped them both, turning them from spiral galaxies into irregular ones.

NGC 4485 is the smaller galaxy in this pair, which provides a real-world example for astronomers to compare to their computer models of galactic collisions. The most intense interaction between these two galaxies is all but over; they have made their closest approach and are now separating. The trail of bright stars and knotty, orange clumps that we see here extending out from NGC 4485 is all that connects them — a trail that spans some 24,000 light-years.

Astronomers believe that many of the stars in this connecting trail could never have existed without the galaxies’ close encounter. When galaxies interact, hydrogen gas is shared between them, triggering intense bursts of star formation. The orange knots of light in this image are examples of such regions, clouded with gas and dust.

A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Kathy van Pelt.

For more information, visit: www.spacetelescope.org/images/potw1419a/

Credit: ESA/Hubble & NASA; Acknowledgment: Kathy van Pelt

Posted by NASA Hubble on 2019-04-11 05:57:45

Tagged: , NGC 4485 , NGC 4490 , Arp 269 , Interacting galaxies , colliding galaxies , galaxy collision , galaxy , galaxies , space , astronomy , NASA , Hubble , Hubble Space Telescope , cosmos , ESA , Hidden Treasures

Galaxy Cluster Mergers in X-Rays

Galaxy Cluster Mergers in X-Rays

Edited Chandra Space Telescope annotated image of how galaxy clusters look in x-rays, over time.

Image source: chandra.harvard.edu/photo/2019/cluster_merge/

Original caption: For the first time, astronomers have found two giant clusters of galaxies that are just about to collide, as reported in a new press release by RIKEN. This observation is important in understanding the formation of structure in the Universe, sincelarge-scale structures—such as galaxies and clusters of galaxies—are thought to grow by collisions and mergers.

The composite image shows the separate galaxy clusters 1E2215 and 1E2216, located about 1.2 billion light years from Earth, captured as they enter a critical phase of merging. Chandra’s X-ray data (blue) have been combined with a radio image from the Giant Metrewave Radio Telescope in India (red). These images were then overlaid on an optical image from the Sloan Digital Sky Survey that shows galaxies and stars in the field of view.

The discovery of 1E2215 and 1E2216 at this stage of merging has enabled astronomers to test their computer simulations of these important collisions. This new result provides evidence of a shock wave that is generated early in the merging process and travels out away from the collision in a perpendicular direction.

Because the merging process takes much longer than a human lifetime, astronomers only see snapshots of the various stages of these collisions. A separate graphic shows 1E2215 and 1E2216, plus two systems at earlier stages before collision (Abell 399/Abell 401, and Abell 1758), and one where the collision has already occurred (CIZA J2242.8). This series of images represents the sequential steps a galaxy cluster would undergo. A labeled version shows the separation between the two clusters and the amount of time, measured in billions of years, before or after impact.

(In the additional four systems of the cluster sequence graphic, only X-ray and radio data are shown. For Abell 399 and Abell 401, the X-ray data are from ROSAT and the radio data are from GMRT. In the Abell 1758 image, the X-ray are from Chandra and the radio data come from GMRT. Finally, the X-ray data in CIZA J2242.8 are from ESA’s XMM-Newton, while the radio data are from the Westerbork Synthesis Radio Telescope in the Netherlands.)

Clusters of galaxies are the largest known objects held together by gravity and consist of hundreds of galaxies that each contain hundreds of billions of stars. Ever since the Big Bang, these objects have been growing by colliding and merging with each other. Due to their large size, with diameters of a few million light years, these collisions can take about a billion years to complete. After the dust has settled, the two colliding clusters will have merged into one bigger cluster.

The result was published in Nature Astronomy on June 24, 2019, by first author Liyi Gu of the RIKEN national science institute in Japan and the SRON Netherlands Institute for Space Research and collaborators. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.

Posted by sjrankin on 2019-07-28 04:19:13

Tagged: , 28 July 2019 , Edited , NASA , Chandra Space Telescope , X-Rays , Galaxies , Galaxy Clusters , Coma Galaxy Cluster , Merge , Stars , Annotated , XMM-Newton , ESA , European Space Agency

Galaxy Cluster Mergers in X-Rays, variant

Galaxy Cluster Mergers in X-Rays, variant

Edited Chandra Space Telescope annotated image of how galaxy clusters look in x-rays, over time. Color/processing variant.

Image source: chandra.harvard.edu/photo/2019/cluster_merge/

Original caption: For the first time, astronomers have found two giant clusters of galaxies that are just about to collide, as reported in a new press release by RIKEN. This observation is important in understanding the formation of structure in the Universe, sincelarge-scale structures—such as galaxies and clusters of galaxies—are thought to grow by collisions and mergers.

The composite image shows the separate galaxy clusters 1E2215 and 1E2216, located about 1.2 billion light years from Earth, captured as they enter a critical phase of merging. Chandra’s X-ray data (blue) have been combined with a radio image from the Giant Metrewave Radio Telescope in India (red). These images were then overlaid on an optical image from the Sloan Digital Sky Survey that shows galaxies and stars in the field of view.

The discovery of 1E2215 and 1E2216 at this stage of merging has enabled astronomers to test their computer simulations of these important collisions. This new result provides evidence of a shock wave that is generated early in the merging process and travels out away from the collision in a perpendicular direction.

Because the merging process takes much longer than a human lifetime, astronomers only see snapshots of the various stages of these collisions. A separate graphic shows 1E2215 and 1E2216, plus two systems at earlier stages before collision (Abell 399/Abell 401, and Abell 1758), and one where the collision has already occurred (CIZA J2242.8). This series of images represents the sequential steps a galaxy cluster would undergo. A labeled version shows the separation between the two clusters and the amount of time, measured in billions of years, before or after impact.

(In the additional four systems of the cluster sequence graphic, only X-ray and radio data are shown. For Abell 399 and Abell 401, the X-ray data are from ROSAT and the radio data are from GMRT. In the Abell 1758 image, the X-ray are from Chandra and the radio data come from GMRT. Finally, the X-ray data in CIZA J2242.8 are from ESA’s XMM-Newton, while the radio data are from the Westerbork Synthesis Radio Telescope in the Netherlands.)

Clusters of galaxies are the largest known objects held together by gravity and consist of hundreds of galaxies that each contain hundreds of billions of stars. Ever since the Big Bang, these objects have been growing by colliding and merging with each other. Due to their large size, with diameters of a few million light years, these collisions can take about a billion years to complete. After the dust has settled, the two colliding clusters will have merged into one bigger cluster.

The result was published in Nature Astronomy on June 24, 2019, by first author Liyi Gu of the RIKEN national science institute in Japan and the SRON Netherlands Institute for Space Research and collaborators. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.

Posted by sjrankin on 2019-07-28 04:19:13

Tagged: , 28 July 2019 , Edited , NASA , Chandra Space Telescope , X-Rays , Galaxies , Galaxy Clusters , Coma Galaxy Cluster , Merge , Stars , Annotated , XMM-Newton , ESA , European Space Agency

Galaxy D100 Losing Gas, variant

Galaxy D100 Losing Gas, variant

Edited Hubble Space Telescope image of galaxies in the Coma Cluster. Of interest is the lighter-colored galaxy in the upper-right with a dark smudge near its center. It’s a very long streamer of hydrogen gas that is being emitted, and causing the spiral arms to eventually disappear. Color/processing variant.

Original caption: The rough-and-tumble environment near the center of the massive Coma galaxy cluster is no match for a wayward spiral galaxy. New images from NASA’s Hubble Space Telescope show a spiral galaxy being stripped of its gas as it plunges toward the cluster’s center. A long, thin streamer of gas and dust stretches like taffy from the galaxy’s core and on into space. Eventually, the galaxy, named D100, will lose all of its gas and become a dead relic, deprived of the material to create new stars and shining only by the feeble glow of old, red stars.

"This galaxy stands out as a particularly extreme example of processes common in massive clusters, where a galaxy goes from being a healthy spiral full of star formation to a ‘red and dead galaxy,’" said William Cramer of Yale University in New Haven, Connecticut, leader of the team using the Hubble observations. "The spiral arms disappear, and the galaxy is left with no gas and only old stars. This phenomenon has been known about for several decades, but Hubble provides the best imagery of galaxies undergoing this process."

Called "ram pressure stripping," the process occurs when a galaxy, due to the pull of gravity, falls toward the dense center of a massive cluster of thousands of galaxies, which swarm around like a hive of bees. During its plunge, the galaxy plows through intergalactic material, like a boat moving through water. The material pushes gas and dust from the galaxy. Once the galaxy loses all of its hydrogen gas — fuel for starbirth — it meets an untimely death because it can no longer create new stars. The gas-stripping process in D100 began roughly 300 million years ago.

In the massive Coma cluster this violent gas-loss process occurs in many galaxies. But D100 is unique in several ways. Its long, thin tail is its most unusual feature. The tail, a mixture of dust and hydrogen gas, extends nearly 200,000 light-years, about the width of two Milky Way galaxies. But the pencil-like structure is comparatively narrow, only 7,000 light-years wide.

"The tail is remarkably well-defined, straight and smooth, and has clear edges," explained team member Jeffrey Kenney, also of Yale University. "This is a surprise because a tail like this is not seen in most computer simulations. Most galaxies undergoing this process are more of a mess. The clean edges and filamentary structures of the tail suggest that magnetic fields play a prominent role in shaping it. Computer simulations show that magnetic fields form filaments in the tail’s gas. With no magnetic fields, the tail is more clumpy than filamentary."

The researchers’ main goal was to study star formation along the tail. Hubble’s sharp vision uncovered the blue glow of clumps of young stars. The brightest clump in the middle of the tail contains at least 200,000 stars, triggered by the ongoing gas loss from the galaxy. However, based on the amount of glowing hydrogen gas contained in the tail, the team had expected Hubble to uncover three times more stars than it detected.

The Subaru Telescope in Hawaii observed the glowing tail in 2007 during a survey of the Coma cluster’s galaxies. But the astronomers needed Hubble observations to confirm that the hot hydrogen gas contained in the tail was a signature of star formation.

"Without the depth and resolution of Hubble, it’s hard to say if the glowing hydrogen-gas emission is coming from stars in the tail or if it’s just from the gas being heated," Cramer said. "These Hubble visible-light observations are the first and best follow-up of the Subaru survey."

The Hubble data show that the gas-stripping process began on the outskirts of the galaxy and is moving in towards the center, which is typical in this type of mass loss. Based on the Hubble images, the gas has been cleared out all the way down to the central 6,400 light-years.

Within that central region, there is still a lot of gas, as seen in a burst of star formation. "This region is the only place in the galaxy where gas exists and star formation is taking place," Cramer said. "But now that gas is being stripped out of the center, forming the long tail."

Adding to this compelling narrative is another galaxy in the image that foreshadows D100’s fate. The object, named D99, began as a spiral galaxy similar in mass to D100. It underwent the same violent gas-loss process as D100 is now undergoing, and is now a dead relic. All of the gas was siphoned from D99 between 500 million and 1 billion years ago. Its spiral structure has mostly faded away, and its stellar inhabitants consist of old, red stars. "D100 will look like D99 in a few hundred million years," Kenney said.

The Coma cluster is located 330 million light-years from Earth.

The team’s results appear online in the January 8, 2019, issue of The Astrophysical Journal.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Posted by sjrankin on 2019-01-28 08:19:59

Tagged: , 28 January 2019 , Edited , STSCI-H-p1905a-m-2000×1543 , Galaxy , Galaxies , Hydrogen , Coma Cluster , D100 , Galaxy D100

Galaxy D100 Losing Gas, variant

Galaxy D100 Losing Gas, variant

Edited Hubble Space Telescope image of galaxies in the Coma Cluster. Of interest is the lighter-colored galaxy in the upper-right with a dark smudge near its center. It’s a very long streamer of hydrogen gas that is being emitted, and causing the spiral arms to eventually disappear. Color/processing variant.

Original caption: The rough-and-tumble environment near the center of the massive Coma galaxy cluster is no match for a wayward spiral galaxy. New images from NASA’s Hubble Space Telescope show a spiral galaxy being stripped of its gas as it plunges toward the cluster’s center. A long, thin streamer of gas and dust stretches like taffy from the galaxy’s core and on into space. Eventually, the galaxy, named D100, will lose all of its gas and become a dead relic, deprived of the material to create new stars and shining only by the feeble glow of old, red stars.

"This galaxy stands out as a particularly extreme example of processes common in massive clusters, where a galaxy goes from being a healthy spiral full of star formation to a ‘red and dead galaxy,’" said William Cramer of Yale University in New Haven, Connecticut, leader of the team using the Hubble observations. "The spiral arms disappear, and the galaxy is left with no gas and only old stars. This phenomenon has been known about for several decades, but Hubble provides the best imagery of galaxies undergoing this process."

Called "ram pressure stripping," the process occurs when a galaxy, due to the pull of gravity, falls toward the dense center of a massive cluster of thousands of galaxies, which swarm around like a hive of bees. During its plunge, the galaxy plows through intergalactic material, like a boat moving through water. The material pushes gas and dust from the galaxy. Once the galaxy loses all of its hydrogen gas — fuel for starbirth — it meets an untimely death because it can no longer create new stars. The gas-stripping process in D100 began roughly 300 million years ago.

In the massive Coma cluster this violent gas-loss process occurs in many galaxies. But D100 is unique in several ways. Its long, thin tail is its most unusual feature. The tail, a mixture of dust and hydrogen gas, extends nearly 200,000 light-years, about the width of two Milky Way galaxies. But the pencil-like structure is comparatively narrow, only 7,000 light-years wide.

"The tail is remarkably well-defined, straight and smooth, and has clear edges," explained team member Jeffrey Kenney, also of Yale University. "This is a surprise because a tail like this is not seen in most computer simulations. Most galaxies undergoing this process are more of a mess. The clean edges and filamentary structures of the tail suggest that magnetic fields play a prominent role in shaping it. Computer simulations show that magnetic fields form filaments in the tail’s gas. With no magnetic fields, the tail is more clumpy than filamentary."

The researchers’ main goal was to study star formation along the tail. Hubble’s sharp vision uncovered the blue glow of clumps of young stars. The brightest clump in the middle of the tail contains at least 200,000 stars, triggered by the ongoing gas loss from the galaxy. However, based on the amount of glowing hydrogen gas contained in the tail, the team had expected Hubble to uncover three times more stars than it detected.

The Subaru Telescope in Hawaii observed the glowing tail in 2007 during a survey of the Coma cluster’s galaxies. But the astronomers needed Hubble observations to confirm that the hot hydrogen gas contained in the tail was a signature of star formation.

"Without the depth and resolution of Hubble, it’s hard to say if the glowing hydrogen-gas emission is coming from stars in the tail or if it’s just from the gas being heated," Cramer said. "These Hubble visible-light observations are the first and best follow-up of the Subaru survey."

The Hubble data show that the gas-stripping process began on the outskirts of the galaxy and is moving in towards the center, which is typical in this type of mass loss. Based on the Hubble images, the gas has been cleared out all the way down to the central 6,400 light-years.

Within that central region, there is still a lot of gas, as seen in a burst of star formation. "This region is the only place in the galaxy where gas exists and star formation is taking place," Cramer said. "But now that gas is being stripped out of the center, forming the long tail."

Adding to this compelling narrative is another galaxy in the image that foreshadows D100’s fate. The object, named D99, began as a spiral galaxy similar in mass to D100. It underwent the same violent gas-loss process as D100 is now undergoing, and is now a dead relic. All of the gas was siphoned from D99 between 500 million and 1 billion years ago. Its spiral structure has mostly faded away, and its stellar inhabitants consist of old, red stars. "D100 will look like D99 in a few hundred million years," Kenney said.

The Coma cluster is located 330 million light-years from Earth.

The team’s results appear online in the January 8, 2019, issue of The Astrophysical Journal.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Posted by sjrankin on 2019-01-28 08:19:59

Tagged: , 28 January 2019 , Edited , STSCI-H-p1905a-m-2000×1543 , Galaxy , Galaxies , Hydrogen , Coma Cluster , D100 , Galaxy D100

Galaxy D100 Losing Gas

Galaxy D100 Losing Gas

Edited Hubble Space Telescope image of galaxies in the Coma Cluster. Of interest is the lighter-colored galaxy in the upper-right with a dark smudge near its center. It’s a very long streamer of hydrogen gas that is being emitted, and causing the spiral arms to eventually disappear.

Original caption: The rough-and-tumble environment near the center of the massive Coma galaxy cluster is no match for a wayward spiral galaxy. New images from NASA’s Hubble Space Telescope show a spiral galaxy being stripped of its gas as it plunges toward the cluster’s center. A long, thin streamer of gas and dust stretches like taffy from the galaxy’s core and on into space. Eventually, the galaxy, named D100, will lose all of its gas and become a dead relic, deprived of the material to create new stars and shining only by the feeble glow of old, red stars.

"This galaxy stands out as a particularly extreme example of processes common in massive clusters, where a galaxy goes from being a healthy spiral full of star formation to a ‘red and dead galaxy,’" said William Cramer of Yale University in New Haven, Connecticut, leader of the team using the Hubble observations. "The spiral arms disappear, and the galaxy is left with no gas and only old stars. This phenomenon has been known about for several decades, but Hubble provides the best imagery of galaxies undergoing this process."

Called "ram pressure stripping," the process occurs when a galaxy, due to the pull of gravity, falls toward the dense center of a massive cluster of thousands of galaxies, which swarm around like a hive of bees. During its plunge, the galaxy plows through intergalactic material, like a boat moving through water. The material pushes gas and dust from the galaxy. Once the galaxy loses all of its hydrogen gas — fuel for starbirth — it meets an untimely death because it can no longer create new stars. The gas-stripping process in D100 began roughly 300 million years ago.

In the massive Coma cluster this violent gas-loss process occurs in many galaxies. But D100 is unique in several ways. Its long, thin tail is its most unusual feature. The tail, a mixture of dust and hydrogen gas, extends nearly 200,000 light-years, about the width of two Milky Way galaxies. But the pencil-like structure is comparatively narrow, only 7,000 light-years wide.

"The tail is remarkably well-defined, straight and smooth, and has clear edges," explained team member Jeffrey Kenney, also of Yale University. "This is a surprise because a tail like this is not seen in most computer simulations. Most galaxies undergoing this process are more of a mess. The clean edges and filamentary structures of the tail suggest that magnetic fields play a prominent role in shaping it. Computer simulations show that magnetic fields form filaments in the tail’s gas. With no magnetic fields, the tail is more clumpy than filamentary."

The researchers’ main goal was to study star formation along the tail. Hubble’s sharp vision uncovered the blue glow of clumps of young stars. The brightest clump in the middle of the tail contains at least 200,000 stars, triggered by the ongoing gas loss from the galaxy. However, based on the amount of glowing hydrogen gas contained in the tail, the team had expected Hubble to uncover three times more stars than it detected.

The Subaru Telescope in Hawaii observed the glowing tail in 2007 during a survey of the Coma cluster’s galaxies. But the astronomers needed Hubble observations to confirm that the hot hydrogen gas contained in the tail was a signature of star formation.

"Without the depth and resolution of Hubble, it’s hard to say if the glowing hydrogen-gas emission is coming from stars in the tail or if it’s just from the gas being heated," Cramer said. "These Hubble visible-light observations are the first and best follow-up of the Subaru survey."

The Hubble data show that the gas-stripping process began on the outskirts of the galaxy and is moving in towards the center, which is typical in this type of mass loss. Based on the Hubble images, the gas has been cleared out all the way down to the central 6,400 light-years.

Within that central region, there is still a lot of gas, as seen in a burst of star formation. "This region is the only place in the galaxy where gas exists and star formation is taking place," Cramer said. "But now that gas is being stripped out of the center, forming the long tail."

Adding to this compelling narrative is another galaxy in the image that foreshadows D100’s fate. The object, named D99, began as a spiral galaxy similar in mass to D100. It underwent the same violent gas-loss process as D100 is now undergoing, and is now a dead relic. All of the gas was siphoned from D99 between 500 million and 1 billion years ago. Its spiral structure has mostly faded away, and its stellar inhabitants consist of old, red stars. "D100 will look like D99 in a few hundred million years," Kenney said.

The Coma cluster is located 330 million light-years from Earth.

The team’s results appear online in the January 8, 2019, issue of The Astrophysical Journal.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Posted by sjrankin on 2019-01-28 08:20:00

Tagged: , 28 January 2019 , Edited , STSCI-H-p1905a-m-2000×1543 , Galaxy , Galaxies , Hydrogen , Coma Cluster , D100 , Galaxy D100

Smashing Galaxies Together for Bigger Black Holes, variant

Smashing Galaxies Together for Bigger Black Holes, variant

Edited Hubble Space Telescope montage (created by NASA) of various galaxies with growing black holes due to collisions with other galaxies. Color/processing variant.

Original caption: Some of the Hubble Space Telescope’s most stunning images reveal galaxies in distress. Many of them are in the throes of a gravitational encounter with another galaxy. The photos show perfect pinwheel patterns stretched and pulled into irregular shapes. Streamers of gas and dust flow from galaxies into space. And in this chaos, batches of young, blue stars glow like tree lights, fueled by the dust and gas kicked up by the galactic encounter. For some galaxies, the powerful meeting with a passing galaxy will eventually end in mergers.

But hidden from view deep inside the dusty cores of these merging galaxies is the slow dance of their supermassive black holes toward an eventual union. Visible light cannot penetrate these shrouded central regions. X-ray data, however, have detected the black-hole courtship. And now astronomers analyzing near-infrared images from the sharp-eyed Hubble Space Telescope and the W. M. Keck Observatory in Hawaii are offering the best view yet of close pairs of black holes as they move slowly toward each other.

The study is the largest survey of the cores of nearby galaxies in near-infrared light. The Hubble observations represent over 20 years’ worth of snapshots from its vast archive. The survey targeted galaxies residing an average distance of 330 million light-years from Earth.

The census helps astronomers confirm computer simulations showing that black holes grow faster during the last 10 million to 20 million years of the galactic merger. The Hubble and Keck Observatory images captured close-up views of this final stage, when the bulked-up black holes are only about 3,000 light-years apart — a near-embrace in cosmic terms. The study shows that galaxy encounters are important for astronomers’ understanding of how black holes became so monstrously big.

These monster black holes also unleash powerful energy in the form of gravitational waves, the kind of ripples in space-time that were just recently detected by ground-breaking experiments. The images also provide a close-up preview of a phenomenon that must have been more common in the early universe, when galaxy mergers were more frequent.

Another original caption: Peering through thick walls of gas and dust surrounding the messy cores of merging galaxies, astronomers are getting their best view yet of close pairs of supermassive black holes as they march toward coalescence into mega black holes.

A team of researchers led by Michael Koss of Eureka Scientific Inc., in Kirkland, Washington, performed the largest survey of the cores of nearby galaxies in near-infrared light, using high-resolution images taken by NASA’s Hubble Space Telescope and the W. M. Keck Observatory in Hawaii. The Hubble observations represent over 20 years’ worth of snapshots from its vast archive.

"Seeing the pairs of merging galaxy nuclei associated with these huge black holes so close together was pretty amazing," Koss said. "In our study, we see two galaxy nuclei right when the images were taken. You can’t argue with it; it’s a very ‘clean’ result, which doesn’t rely on interpretation."

The images also provide a close-up preview of a phenomenon that must have been more common in the early universe, when galaxy mergers were more frequent. When galaxies collide, their monster black holes can unleash powerful energy in the form of gravitational waves, the kind of ripples in space-time that were just recently detected by ground-breaking experiments.

The new study also offers a preview of what will likely happen in our own cosmic backyard, in several billion years, when our Milky Way combines with the neighboring Andromeda galaxy and their respective central black holes smash together.

"Computer simulations of galaxy smashups show us that black holes grow fastest during the final stages of mergers, near the time when the black holes interact, and that’s what we have found in our survey," said study team member Laura Blecha of the University of Florida, in Gainesville. "The fact that black holes grow faster and faster as mergers progress tells us galaxy encounters are really important for our understanding of how these objects got to be so monstrously big."

A galaxy merger is a slow process lasting more than a billion years as two galaxies, under the inexorable pull of gravity, dance toward each other before finally joining together. Simulations reveal that galaxies kick up plenty of gas and dust as they undergo this slow-motion train wreck.

The ejected material often forms a thick curtain around the centers of the coalescing galaxies, shielding them from view in visible light. Some of the material also falls onto the black holes at the cores of the merging galaxies. The black holes grow at a fast clip as they engorge themselves with their cosmic food, and, being messy eaters, they cause the infalling gas to blaze brightly. This speedy growth occurs during the last 10 million to 20 million years of the union. The Hubble and Keck Observatory images captured close-up views of this final stage, when the bulked-up black holes are only about 3,000 light-years apart — a near-embrace in cosmic terms.

It’s not easy to find galaxy nuclei so close together. Most prior observations of colliding galaxies have caught the coalescing black holes at earlier stages when they were about 10 times farther away. The late stage of the merger process is so elusive because the interacting galaxies are encased in dense dust and gas and require high-resolution observations in infrared light that can see through the clouds and pinpoint the locations of the two merging nuclei.

The team first searched for visually obscured, active black holes by sifting through 10 years’ worth of X-ray data from the Burst Alert Telescope (BAT) aboard NASA’s Neil Gehrels Swift Telescope, a high-energy space observatory. "Gas falling onto the black holes emits X-rays, and the brightness of the X-rays tells you how quickly the black hole is growing," Koss explained. "I didn’t know if we would find hidden mergers, but we suspected, based on computer simulations, that they would be in heavily shrouded galaxies.Therefore we tried to peer through the dust with the sharpest images possible, in hopes of finding coalescing black holes."

The researchers combed through the Hubble archive, identifying those merging galaxies they spotted in the X-ray data. They then used the Keck Observatory’s super-sharp, near-infrared vision to observe a larger sample of the X-ray-producing black holes not found in the Hubble archive.

"People had conducted studies to look for these close interacting black holes before, but what really enabled this particular study were the X-rays that can break through the cocoon of dust," Koss said. "We also looked a bit farther in the universe so that we could survey a larger volume of space, giving us a greater chance of finding more luminous, rapidly growing black holes."

The team targeted galaxies with an average distance of 330 million light-years from Earth. Many of the galaxies are similar in size to the Milky Way and Andromeda galaxies. The team analyzed 96 galaxies from the Keck Observatory and 385 galaxies from the Hubble archive found in 38 different Hubble observation programs. The sample galaxies are representative of what astronomers would find by conducting an all-sky survey.

To verify their results, Koss’s team compared the survey galaxies with 176 other galaxies from the Hubble archive that lack actively growing black holes. The comparison confirmed that the luminous cores found in the researchers’ census of dusty interacting galaxies are indeed a signature of rapidly growing black-hole pairs headed for a collision.

When the two supermassive black holes in each of these systems finally come together in millions of years, their encounters will produce strong gravitational waves. Gravitational waves produced by the collision of two stellar-mass black holes have already been detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO). Observatories such as the planned NASA/ESA space-based Laser Interferometer Space Antenna (LISA) will be able to detect the lower-frequency gravitational waves from supermassive black-hole mergers, which are a million times more massive than those detected by LIGO.

Future infrared telescopes, such as NASA’s planned James Webb Space Telescope and a new generation of giant ground-based telescopes, will provide an even better probe of dusty galaxy collisions by measuring the masses, growth rate, and dynamics of close black-hole pairs. The Webb telescope may also be able to look in mid-infrared light to uncover more galaxy interactions so encased in thick gas and dust that even near-infrared light cannot penetrate them.

The team’s results will appear online in the Nov. 7, 2018, issue of the journal Nature.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Posted by sjrankin on 2018-11-08 03:32:08

Tagged: , STSCI-H-p1828a-f-2422×2117 , Edited , NASA , ESA , Montage , HST , Hubble Space Telescope , Galaxies , IR , Infrared , European Space Agency , Black Hole

Star Dust Looping Animation

Star Dust Looping Animation

Seamlessly Looping Background Animation Of Comets And Nebula To Spiral Galaxies And Star-Born Explosions. Checkout GlobalArchive.com, contact ChrisDortch@gmail.com, and connect to www.linkedin.com/in/chrisdortch

Posted by globalarchive on 2017-03-22 03:51:53

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Star Dust Looping Animation

Star Dust Looping Animation

Seamlessly Looping Background Animation Of Comets And Nebula To Spiral Galaxies And Star-Born Explosions. Checkout GlobalArchive.com, contact ChrisDortch@gmail.com, and connect to www.linkedin.com/in/chrisdortch

Posted by globalarchive on 2017-03-20 06:14:54

Tagged: , Seamless , Electric , Pattern , Art , Dj , Experiment , Stars , Party , Planet , Galaxies , Outer , Fractal , Power , Beautiful , Futuristic , Digital , Universe , Cosmos , Cool , Render , Galaxy , Awesome , Computer , Fantasy , Amazing , Comet , Concept , Abstract , Dream , Geometric , Space , Virtual , Best , Star , Modern , Effects , Loop , Animation , Imagination , Looping , Multi-Verse , Nebula , Dust , Spiral , Design , Animated , Creative , 3D , Energy