Latest Active galactic nucleus Stories

2012-06-03 07:46:03

Astronomers studying the galaxy NGC 4151 with ESA's XMM-Newton space observatory have detected X-rays emitted and then reflected by ionised iron atoms very close to the supermassive black hole hosted at the galaxy's core. By measuring the time delays occurring in these 'reverberation' events, they were able to map the vicinity of this black hole in unprecedented detail. Supermassive black holes are enormous concentrations of matter, weighing millions to billions of times the mass of the...

Gamma Rays From Milky Way’s Past Show Historically Active Black Hole
2012-05-30 03:39:18

Lee Rannals for RedOrbit.com Gamma-ray beams seen in the Milky Way's central black hole suggest that the galaxy's center was much more active in the past, according to new research. Harvard University astrophysicists used an image taken by NASA's Fermi space telescope to reveal gamma-rays from the Milky Way millions of years ago. "These faint jets are a ghost or after-image of what existed a million years ago," Meng Su, an astronomer at the Harvard-Smithsonian Center for Astrophysics...

Astrophysicists Use Three-Telescope Interferometry To Observe How Black Holes Are Fueled
2012-05-18 03:45:33

By combining the light of three powerful infrared telescopes, an international research team has observed the active accretion phase of a supermassive black hole in the center of a galaxy tens of millions of light years away, a method that has yielded an unprecedented amount of data for such observations. The resolution at which they were able to observe this highly luminescent active galactic nucleus (AGN) has given them direct confirmation of how mass accretes onto black holes in centers of...

XMM-Newton Measures The Power Of Black-hole Driven Outflows
2012-02-28 05:01:35

A curious correlation between the mass of a galaxy's central black hole and the velocity of stars in a vast, roughly spherical structure known as its bulge has puzzled astronomers for years. An international team led by Francesco Tombesi at NASA's Goddard Space Flight Center in Greenbelt, Md., now has identified a new type of black-hole-driven outflow that appears to be both powerful enough and common enough to explain this link. Most big galaxies contain a central black hole weighing...

ALMA Reveals Starving Galaxies
2012-01-11 13:06:43

Astronomers using the partially completed ALMA observatory have found compelling evidence for how star-forming galaxies evolve into 'red and dead' elliptical galaxies, catching a large group of galaxies right in the middle of this change. For years, astronomers have been developing a picture of galaxy evolution in which mergers between spiral galaxies could explain why nearby large elliptical galaxies have so few young stars. The theoretical picture is chaotic and violent: The merging...

Image 1 - Telescopes Pinpoint Black Hole's Outburst
2012-01-11 04:05:14

[ Watch the Video ] Using observations from NASA's Rossi X-ray Timing Explorer (RXTE) satellite and the National Science Foundation's (NSF) Very Long Baseline Array (VLBA) radio telescope, an international team of astronomers has identified the moment when a black hole in our galaxy launched super-fast knots of gas into space. Racing outward at about one-quarter the speed of light, these "bullets" of ionized gas are thought to arise from a region located just outside the black hole's...

Image 1 - Suspects Exonerated In The Quenching Of Star Formation
2011-10-12 04:23:27

Supermassive black holes millions to billions times the mass of our Sun lie at the heart of most, maybe all large galaxies. Some of these power brilliantly luminous, rapidly growing objects called active galactic nuclei that gather and condense enormous quantities of dust, gas and stars. Because astronomers had seen these objects primarily in the oldest, most massive galaxies that glow with the red light of aging stars, many thought active galactic nuclei might help to bring an end to the...

2011-10-11 09:28:03

Astrophysicists have found evidence of black holes destroying stars, a long-sought phenomenon that provides a new window into general relativity. The research, reported in the latest issue of the Astrophysical Journal, also opens up a method to search for the possible existence of a large population of presently undetectable "intermediate mass" black holes which are hypothesized to be precursors to the super-massive black holes at the centers of most large galaxies. The study was carried...

Latest Active galactic nucleus Reference Libraries

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....

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...

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...

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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Word of the Day
  • An evil spirit; a devil.
  • A nightmare.
  • In astrology, the twelfth house of a scheme or figure of the heavens: so called from its signifying dreadful things, such as secret enemies, great losses, imprisonment, etc.
'Cacodemon' comes from a Greek term meaning 'evil genius.'