Smashing Galaxies Together for Bigger Black Holes

Smashing Galaxies Together for Bigger Black Holes

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

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

The Core of Barred Spiral Galaxy NGC 1365

The Core of Barred Spiral Galaxy NGC 1365

The barred spiral galaxy NGC 1365 in Fornax is feeding material into its central region, igniting massive star birth and probably causing its bulge of stars to grow. The material also is fueling a black hole in the galaxy’s core. A galaxy’s bulge is a central, football-shaped structure composed of stars, gas, and dust.

A barred spiral galaxy is characterized by a lane of stars, gas, and dust slashing across a galaxy’s central region. It has a small bulge that is dominated by a disk of material. The spiral arms begin at both ends of the bar. The bar is funneling material into the hub, which triggers star formation and feeds the bulge. This Hubble image reveals only the core of the galaxy within its elongated bulge. The galaxy’s two large and prominent spiral arms are well outside the field of view.

For more information, visit: hubblesite.org/news_release/news/1999-34

Credit: Allan Sandage (The Observatories of the Carnegie Institution of Washington) and John Bedke (Computer Sciences Corporation and the Space Telescope Science Institute), John Trauger (Jet Propulsion Laboratory), NASA, ESA, Rainier Peleti, and C. Marcella Carollo (Johns Hopkins University and Columbia University)

Posted by NASA Hubble on 2018-05-18 18:14:17

Tagged: , NGC 1365 , Hubble , NASA , space , cosmos , astronomy , galaxy , barred spiral galaxy , Hubble Space Telescope , black hole

Deep Magellanic Clouds Image Indicates Collisions

Deep Magellanic Clouds Image Indicates Collisions

Did the two most famous satellite galaxies of our Milky Way Galaxy once collide? No one knows for sure, but a detailed inspection of deep images like that featured here give an indication that they have. Pictured, the Large Magellanic Cloud (LMC) is on the top left and the Small Magellanic Cloud (SMC) is on the bottom right. The surrounding field is monochrome color-inverted to highlight faint filaments, shown in gray. Perhaps surprisingly, the featured research-grade image was compiled with small telescopes to cover the large angular field — nearly 40 degrees across. Much of the faint nebulosity is Galactic Cirrus clouds of thin dust in our own Galaxy, but a faint stream of stars does appear to be extending from the SMC toward the LMC. Also, stars surrounding the LMC appear asymmetrically distributed, indicating in simulations that they could well have been pulled off gravitationally in one or more collisions. Both the LMC and the SMC are visible to the unaided eye in southern skies. Future telescopic observations and computer simulations are sure to continue in a continuing effort to better understand the history of our Milky Way and its surroundings. via NASA ift.tt/29Zk4Ml

Posted by thetechreader.com on 2016-07-26 04:23:19

Tagged: , IFTTT , NASA

Earthview on glass – NASA 72-HC-660 (AS-16 mission)

Earthview on glass - NASA 72-HC-660 (AS-16 mission)

PROJECT PREVIEW: The first images of the Earth ever produced photographically on glass

Read more here: www.glasslanternslides.com/heavens

——-

From a personal archive of original NASA film, our upcoming series of modern-era glass lantern slides are believed to be the very first documented true photographic prints of the Earth produced via the antique, glass dry plate method.

From the original snapshot taken on 70mm film in space circa. 1972, to this circa. 2020 glass dry plate, all iterations of the image are true darkroom photographs. No scanning or otherwise digitization was employed at any stage.

This photographic print of the Earth has never touched a computer. Thus it is truly a product of the natural order (ie. light and chemistry).

The particular plate shown here was produced from the original NASA 4×5 Kodak color transparency film. Being that the source film was a positive image, an internegative needed to be created in order for additional positive prints to be produced. The internegative was made via the contact print method on black and white sheet film and the b/w negative was then used to contact print the glass plate positive.

This picture shows the original, untouched glass slide (3-1/4 x 4) on a light table with no cover plate. Finished glass lantern slides with glass cover plates, paper mats/labels and taped-sealed edges will be available to order in the near future.

NOTE: Little dust particles, flaws and inconsistencies in the emulsion density, etc. are a natural part of the antique dry plate product.

Official photograph description and specs from NASA:

Serial Number: AS16-118-18885
Transparency film code: 72-HC-660
Photograph Date: 1972-04-16
Central Latitude/Longitude (deg): +35.,110.
Original Film: Kodak 70mm Ektachrome Reversal
Film type: SO-368
Camera: 70mm Hasselblad
Lens: Zeiss

"Apollo 16 view of the Earth taken with a hand-held Hasselblad camera about an hour and a half after translunar injection on 16 April, 1972. Most of the United States is visible at right center, including Lake Michigan and Lake Superior and Florida. Mexico and part of Central America are also visible. The slightly different shade of blue below Florida is the Bahama Banks. The Earth is 12,740 km in diameter and north is at roughly 1:00."

Posted by Glass Lantern Slides on 2020-07-30 02:27:52

Tagged: , NASA , Apollo , 16 , Earth , glass , lantern , slide , dry , plate , space , Earthview

Exoplanet Apparently Disappears in Latest Hubble Observations

Exoplanet Apparently Disappears in Latest Hubble Observations

Now you see it, now you don’t.

What astronomers thought was a planet beyond our solar system has now seemingly vanished from sight. Though this happens in science fiction, such as Superman’s home planet Krypton exploding, astronomers are looking for a plausible explanation.

One interpretation is that, rather than being a full-sized planetary object, which was first photographed in 2004, it could instead be a vast, expanding cloud of dust produced in a collision between two large bodies orbiting the bright nearby star Fomalhaut. Potential follow-up observations might confirm this extraordinary conclusion.

"These collisions are exceedingly rare and so this is a big deal that we actually get to see one," said András Gáspár of the University of Arizona, Tucson. "We believe that we were at the right place at the right time to have witnessed such an unlikely event with NASA’s Hubble Space Telescope."

"The Fomalhaut system is the ultimate test lab for all of our ideas about how exoplanets and star systems evolve," added George Rieke of the University of Arizona’s Steward Observatory. "We do have evidence of such collisions in other systems, but none of this magnitude has been observed in our solar system. This is a blueprint of how planets destroy each other."

The object, called Fomalhaut b, was first announced in 2008, based on data taken in 2004 and 2006. It was clearly visible in several years of Hubble observations that revealed it was a moving dot. Until then, evidence for exoplanets had mostly been inferred through indirect detection methods, such as subtle back-and-forth stellar wobbles and shadows from planets passing in front of their stars.

Unlike other directly imaged exoplanets, however, nagging puzzles arose with Fomalhaut b early on. The object was unusually bright in visible light, but did not have any detectable infrared heat signaturewhen observed by NASA’s Spitzer Space Telescope. Astronomers conjectured that the added brightness came from a huge shell or ring of dust encircling the planet that may possibly have been collision-related. The orbit of Fomalhaut b also appeared unusual, possibly very eccentric.

"Our study, which analyzed all available archival Hubble data on Fomalhaut revealed several characteristics that together paint a picture that the planet-sized object may never have existed in the first place," said Gáspár.

The team emphasizes that the final nail in the coffin came when their data analysis of Hubble images taken in 2014 showed the object had vanished, to their disbelief. Adding to the mystery, earlier images showed the object to continuously fade over time, they say. "Clearly, Fomalhaut b was doing things a bona fide planet should not be doing," said Gáspár.

The interpretation is that Fomalhaut b is slowly expanding from the smashup that blasted a dissipating dust cloud into space. Taking into account all available data, Gáspár and Rieke think the collision occurred not too long prior to the first observations taken in 2004. By now the debris cloud, consisting of dust particles around 1 micron (1/50th the diameter of a human hair), is below Hubble’s detection limit. The dust cloud is estimated to have expanded by now to a size larger than the orbit of Earth around our Sun.

Equally confounding is that the team reports that the object is more likely on an escape path, rather than on an elliptical orbit, as expected for planets. This is based on the researchers adding later observations to the trajectory plots from earlier data. "A recently created massive dust cloud, experiencing considerable radiative forces from the central star Fomalhaut, would be placed on such a trajectory," said Gáspár. "Our model is naturally able to explain all independent observable parameters of the system: its expansion rate, its fading and its trajectory."

Because Fomalhaut b is presently inside a vast ring of icy debris encircling the star, colliding bodies would likely be a mixture of ice and dust, like the comets that exist in the Kuiper belt on the outer fringe of our solar system. Gáspár and Rieke estimate that each of these comet-like bodies measured about 125 miles (200 kilometers) across (roughly half the size of the asteroid Vesta).

According to the authors, their model explains all the observed characteristics of Fomalhaut b. Sophisticated dust dynamical modeling done on a cluster of computers at the University of Arizona shows that such a model is able to fit quantitatively all the observations. According to the author’s calculations, the Fomalhaut system, located about 25 light-years from Earth, may experience one of these events only every 200,000 years.

Gáspár and Rieke — along with other members of an extended team — will also be observing the Fomalhaut system with NASA’s upcoming James Webb Space Telescope in its first year of science operations. The team will be directly imaging the inner warm regions of the system, spatially resolving for the first time the elusive asteroid-belt component of an extrasolar planetary system. The team will also search for bona fide planets orbiting Fomalhaut that might be gravitationally sculpting the outer disk. They will also analyze the chemical composition of the disk.

Their paper, "New HST [Hubble] data and modeling reveal a massive planetesimal collision around Fomalhaut" is being published on April 20, 2020, in the Proceedings of the National Academy of Sciences.

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.

For more information: www.nasa.gov/feature/goddard/2020/exoplanet-apparently-di…

Credits: NASA, ESA, and A. Gáspár and G. Rieke (University of Arizona)

Posted by NASA Hubble on 2020-07-31 15:35:11

Tagged: , NASA , Hubble Space Telescope , Hubble , exoplanet , Astronomy , Universe , Space , Science

Gale Crater Scene 3, variant

Gale Crater Scene 3, variant

Panorama of Curiosity images of a scene in Gale Crater. Images taken before her computer glitch that silenced her for a month or so. Possible duplicate. Color/processing variant.

Posted by sjrankin on 2018-11-15 05:29:41

Tagged: , 15 November 2018 , Edited , NASA , Mars , MSL , Curiosity , Gale Crater , Panorama , Rocks , Sand , Dust

Gale Crater Scenic Panorama 4, variant

Gale Crater Scenic Panorama 4, variant

Panorama of Curiosity images of a scene from Gale Crater. (Recently, Curiosity downloaded many images from before her computer glitch and so I made panoramas from them – some of them may be duplicates…) Color/processing variant.

Posted by sjrankin on 2018-11-17 13:51:22

Tagged: , 17 November 2018 , Edited , NASA , Mars , Panorama , Dust , Sand , Rocks , Gale Crater , MSL , Curiosity

Gale Crater Scenic Panorama 4, variant

Gale Crater Scenic Panorama 4, variant

Panorama of Curiosity images of a scene from Gale Crater. (Recently, Curiosity downloaded many images from before her computer glitch and so I made panoramas from them – some of them may be duplicates…) Color/processing variant.

Posted by sjrankin on 2018-11-17 13:51:22

Tagged: , 17 November 2018 , Edited , NASA , Mars , Panorama , Dust , Sand , Rocks , Gale Crater , MSL , Curiosity

Gale Crater Scenic Panorama 3, variant

Gale Crater Scenic Panorama 3, variant

Panorama of Curiosity images of a scene from Gale Crater. (Recently, Curiosity downloaded many images from before her computer glitch and so I made panoramas from them – some of them may be duplicates…) Color/processing variant.

Posted by sjrankin on 2018-11-17 13:51:24

Tagged: , 17 November 2018 , Edited , NASA , Mars , Panorama , Dust , Sand , Rocks , Gale Crater , MSL , Curiosity

Gale Crater Scenic Panorama 1

Gale Crater Scenic Panorama 1

Panorama of Curiosity images of a scene from Gale Crater. (Recently, Curiosity downloaded many images from before her computer glitch and so I made panoramas from them – some of them may be duplicates…)

Posted by sjrankin on 2018-11-17 13:51:30

Tagged: , 17 November 2018 , Edited , NASA , Mars , Panorama , Dust , Sand , Rocks , Gale Crater , MSL , Curiosity