APOD: Black Holes in Merging Galaxies (2010 May 29)

[APOD Robot]

Black Holes in Merging Galaxies

Explanation: Violent galaxy mergers can feed supermassive black holes. Theoretically, the result is intense emission from regions near the supermassive black holes, creating the some of the most luminous objects in the universe. Astronomers dub these Active Galactic Nuclei, or just AGN. But for decades only about 1 percent of AGN seemed to be associated with galaxy mergers. New results from a premier sky survey by NASA's Swift satellite at hard (energetic) X-ray energies now solidly show a strong association of AGN with merging galaxies, though. The hard X-rays more readily penetrate dust and gas clouds in merging galaxies and reveal the presence of emission from the active black holes. In fact, these panels show the location (circled) of Swift X-ray detected supermassive black holes in a variety of merging galaxy systems. The optical images are from the Kitt Peak National Observatory in Arizona. At top center is NGC 7319 and the compact galaxy group known as Stephan's Quintet.

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[bystander]

http://asterisk.apod.com/vie ... 31&t=19560

[Star*Hopper]

Re the object/image ID'd as NGC 1142;
I read there was/are some cataloging "misunderstandings" re this object, but believe they only pertained to the ARP data. However, the position plot for this pictured object indicates it is actually NGC 1144 (circled) and the merging NGC 1143....and DSS images match this perfectly & identify them as 44 & 43, not 42. Does anyone have info or other reference supporting the pictured galaxy is NGC 1142, as labeled?

Also, I can find absolutely NO reference to anything ID'd as MCG 0212050 (center image, bottom row), thru either SIMBAD, NEDS, HEASARC (among others) nor even directly in the Morphological Catalog of Galaxies (MCG) itself. If someone could please provide the J2000 RA-Dec coords or a valid x-ref designation for this object, I'd greatly appreciate it.

Clear'ns!
~S*H

[Case]

Also, I can find absolutely NO reference to anything ID'd as MCG 0212050 (center image, bottom row), thru either SIMBAD, NEDS, HEASARC (among others) nor even directly in the Morphological Catalog of Galaxies (MCG) itself. If someone could please provide the J2000 RA-Dec coords or a valid x-ref designation for this object, I'd greatly appreciate it.

The usual MCG notation uses a plus/minus sign and dashes, like “MCG -02-12-050”, which is listed on NED and SIMBAD. RA 69.559125 Dec -10.795917 or 04h38m14.19s -10d47m45.3s.
Also known as PGC 015703.

[Star*Hopper]

That's the one - mucho thanx Case!
Actually, I had tried it with the requisite dashes, but apparently the leading 0's in the first & final group were throwing the data sites' search off.
Clear'ns!
~S*H

[madmax7stl]

In the associated pictures of active galactic centers (AGN's) I can see up to three or four galaxies colliding. Why is only one black hole active? I am under the understanding that most galaxies, at least most spiral galaxies, have a central black hole. Wouldn't all the black holes in a interacting system become active as they collided?

[harry]

G'day

Black holes have a degree in activity

This link has a bit more info


Stephan's Quintet - A Mammoth Cosmic Collision
http://www.spacetelescope.org/news/heic0007/

in a pdf

http://www.spacetelescope.org/static/ar ... ic0007.pdf

and
Galactic wreckage in Stephan's Quintet
http://www.spacetelescope.org/images/heic0910i/

Three of the galaxies have distorted shapes, elongated spiral arms, and long, gaseous tidal tails containing myriad star clusters, proof of their close encounters. These interactions have sparked a frenzy of star birth in the central pair of galaxies. This drama is being played out against a rich backdrop of faraway galaxies.

The image, taken in visible and near-infrared light, showcases WFC3's broad wavelength range. The colours trace the ages of the stellar populations, showing that star birth occurred at different epochs, stretching over hundreds of millions of years. The camera's infrared vision also peers through curtains of dust to see groupings of stars that cannot be seen in visible light.

NGC 7319, at top right, is a barred spiral with distinct spiral arms that follow nearly 180 degrees back to the bar. The blue specks in the spiral arm at the top of NGC 7319 and the red dots just above and to the right of the core are clusters of many thousands of stars. Most of the Quintet is too far away even for Hubble to resolve individual stars.

Continuing clockwise, the next galaxy appears to have two cores, but it is actually two galaxies, NGC 7318A and NGC 7318B. Encircling the galaxies are young, bright blue star clusters and pinkish clouds of glowing hydrogen where infant stars are being born. These stars are less than 10 million years old and have not yet blown away their natal cloud. Far away from the galaxies, at right, is a patch of intergalactic space where many star clusters are forming.

NGC 7317, at bottom left, is a normal-looking elliptical galaxy that is less affected by the interactions.

Sharply contrasting with these galaxies is the dwarf galaxy NGC 7320 at upper left. Bursts of star formation are occurring in the galaxy's disc, as seen by the blue and pink dots. In this galaxy, Hubble can resolve individual stars, evidence that NGC 7320 is closer to Earth. NGC 7320 is 40 million light-years from Earth. The other members of the Quintet reside about 300 million light-years away in the constellation Pegasus.

It seems that AGN are quite active in all galaxies.