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Latest Active galactic nucleus Stories

c2b6a5ac876bca939f643a62437d01141
2010-06-24 13:05:00

Using two of the world's largest telescopes, an international team of astronomers have found evidence of a collision between galaxies driving intense activity in a highly luminous quasar. The scientists, led by Montserrat Villar Martin of the Instituto de Astrofisica de Andalucía-CSIC in Spain, used the Very Large Telescope (VLT) in Chile and the Gran Telescopio Canarias (GTC) on La Palma in the Canary Islands, to study activity from the quasar SDSS J0123+00. They publish...

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2010-05-26 12:50:00

Data from an ongoing survey by NASA's Swift satellite have helped astronomers solve a decades-long mystery about why a small percentage of black holes emit vast amounts of energy. Only about one percent of supermassive black holes exhibit this behavior. The new findings confirm that black holes "light up" when galaxies collide, and the data may offer insight into the future behavior of the black hole in our own Milky Way galaxy. The study will appear in the June 20 issue of The Astrophysical...

2010-05-26 11:50:00

WASHINGTON, May 26 /PRNewswire-USNewswire/ -- Data from an ongoing survey by NASA's Swift satellite have helped astronomers solve a decades-long mystery about why a small percentage of black holes emit vast amounts of energy. (Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO) Only about one percent of supermassive black holes exhibit this behavior. The new findings confirm that black holes "light up" when galaxies collide, and the data may offer insight into the future...

c05bf85543904881ee1980d79840080f1
2010-05-25 14:01:50

Previous galaxy merger is likely cause A team of astronomy researchers at Florida Institute of Technology and Rochester Institute of Technology in the United States and University of Sussex in the United Kingdom, find that the supermassive black hole (SMBH) at the center of the most massive local galaxy (M87) is not where it was expected. Their research, conducted using the Hubble Space Telescope (HST), concludes that the SMBH in M87 is displaced from the galaxy center. The most likely cause...

e403e3516a8579c6377682457e91f86e1
2010-05-11 13:37:18

Using observations with NASA's Chandra X-ray Observatory and ESA's XMM-Newton, astronomers have announced a robust detection of a vast reservoir of intergalactic gas about 400 million light years from Earth. This discovery is the strongest evidence yet that the "missing matter" in the nearby Universe is located in an enormous web of hot, diffuse gas. This missing matter "” which is different from dark matter -- is composed of baryons, the particles, such as protons and electrons, that...

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2010-05-11 10:00:00

Supermassive black holes with the mass of many millions of stars have been detected at the center of many large galaxies. A super-massive black hole acts like a lurking "monster" at the center of the galaxy which swallows the surrounding material through the intensity of its gravitational pull. X-ray observations indicate that a large amount of energy is produced by the in-fall of matter into a black hole, and ejected in powerful jets. Astronomers from the Max Planck Institute for...

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2010-04-14 08:35:00

Astronomers investigating why the cosmic background radiation is much brighter at radio wavelengths than expected have identified a potential culprit: fast spinning black holes early in the galaxy formation process. The results will be presented by Professor Andy Lawrence at the RAS National Astronomy Meeting in Glasgow on Wednesday April 14th. Last July, US astronomers announced surprising results from a high-altitude balloon experiment called ARCADE-2, which had made careful measurements of...

519d7e5ee817fa0a06610d7b9da255df
2010-04-01 15:40:00

If our eyes could see radio waves, the nearby galaxy Centaurus A (Cen A) would be one of the biggest and brightest objects in the sky, nearly 20 times the apparent size of a full moon. What we can't see when looking at the galaxy in visible light is that it lies nestled between a pair of giant radio-emitting gas plumes ejected by its supersized black hole. Each plume is nearly a million light-years long. NASA's Fermi Gamma-Ray Space Telescope maps gamma rays, radiation that typically packs...

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2010-03-25 06:55:00

Up to now, primitive black holes, which occupy the cores of active galaxies and were around as far back as the early days of the universe, only existed in astronomer's models. Researchers have now found two such gravitational monsters, however, which revealed themselves as brightly glowing quasars. Their light originates from a time when the universe was barely one billion years old - and we can see them now exactly as they appeared 12.7 billion years ago (Nature, March 18, 2010). A quasar is...

0a8a298f190fc7fe998d07de282d38ce1
2010-03-17 13:20:00

Quasars are active and very powerful black holes at the center of distant galaxies. The black holes are extremely massive weighing between 100 million and 10 billion solar masses and rotating around the super massive black hole is a disc of gas and dust. The inner ring of the disc moves faster than the outer rings. The movement causes the material in the rings to rub against each other, heating it and causing it to emit light. Near to the black hole it becomes so hot that X-ray radiation is...


Latest Active galactic nucleus Reference Libraries

6_c7a74d948ad4cfdc1dd54ceada2509fb2
2004-10-19 04:45:42

Seyfert Galaxy -- Seyfert galaxies are spiral or irregular galaxies containing an extremely bright nucleus, most likely caused by a supermassive black hole, that can sometimes outshine the surrounding galaxy. The light from the central nucleus varies in less than a year, which implies that the emitting region must be less than one light year across. They are named for the astronomer Carl Seyfert, who studied them extensively in the 1940s. They are a subclass of active galactic nuclei....

6_0ba47eab12382e6a4e2cc12b1c7ddf782
2004-10-19 04:45:42

Quasar -- A quasar (from quasi-stellar radio source) is an astronomical object that looks like a star in optical telescopes (i.e. it is a point source), but has a very high redshift. The general consensus is that this high redshift is cosmological, the result of Hubble's law and that their redshift indicates that they are typically very distant from Earth; we observe them as they were several billions of years ago. Since we can see them despite their distance, they must emit more...

6_3e166ea744352dc86330d77d6feb4abd2
2004-10-19 04:45:41

Active Galaxy -- An active galaxy is a galaxy where a significant fraction of the energy output is not emitted from normal stellar populations or interstellar gas. This energy, depending on the active galaxy type, can be emitted across most of the electromagnetic spectrum, as infrared, radio waves, UV, X-ray and gamma rays. Frequently, the abbreviation AGN (Active Galactic Nuclei) is used, since most of the active galaxies emit most of their radiation from a narrow region in their...

3_54318e1880d81bf6c92376b6217cbdef2
2004-10-19 04:45:40

Circinus Galaxy -- Resembling a swirling witch's cauldron of glowing vapors, the black hole-powered core of a nearby active galaxy appears in this colorful NASA Hubble Space Telescope image. The galaxy lies 13 million light-years away in the southern constellation Circinus. This galaxy is designated a type 2 Seyfert, a class of mostly spiral galaxies that have compact centers and are believed to contain massive black holes. Seyfert galaxies are themselves part of a larger class of objects...

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