Image: SDSS J1254+0846 (A Quasar pair)
This composite image shows the effects of two galaxies caught in the act of merging.
- Quasars are some of the most luminous objects in the Universe.
- The system SDSS 1254+0846 has a pair of them -- the first time this has been seen.
- This double quasar is likely the result of a merger of two galaxies
"Astronomers have found the first clear evidence of a binary quasar within a pair of actively merging galaxies. Quasars are the extremely bright centers of galaxies surrounding super-massive black holes, and binary quasars are pairs of quasars bound together by gravity. Binary quasars, like other quasars, are thought to be the product of galaxy mergers. Until now, however, binary quasars have not been seen in galaxies that are unambiguously in the act of merging."
"But images of a new binary quasar from the Carnegie Institution's Magellan telescope in Chile show two distinct galaxies with "tails" produced by tidal forces from their mutual gravitational attraction."
"This is really the first case in which you see two separate galaxies, both with quasars, that are clearly interacting," says Carnegie astronomer John Mulchaey who made observations crucial to understanding the galaxy merger.
"Most, if not all, large galaxies, such as our galaxy the Milky Way, host super-massive black holes at their centers. Because galaxies regularly interact and merge, astronomers have assumed that binary super-massive black holes have been common in the Universe, especially during its early history."
"The binary quasar, labeled SDSS J1254+0846, was initially detected by the Sloan Digital Sky Survey, a large scale astronomical survey of galaxies and over 120,000 quasars. Further observations by Paul Green of the Harvard-Smithsonian Center for Astrophysics and colleagues* using NASA's Chandra's X-ray.
Observatory and telescopes at Kitt Peak National Observatory in Arizona and Palomar Observatory in California indicated that the object was likely a binary quasar in the midst of a galaxy merger. Carnegie's Mulchaey then used the 6.5 meter Baade-Magellan telescope at the Las Campanas observatory in Chile to obtain deeper images and more detailed spectroscopy of the merging galaxies."
"Just because you see two galaxies that are close to each other in the sky doesn't mean they are merging," says Mulchaey. "But from the Magellan images we can actually see tidal tails, one from each galaxy, which suggests that the galaxies are in fact interacting and are in the process of merging."
To see a movie of movie of a numerical simulation which shows a galaxy merger similar to SDSS J1254+0846 go to the following website: http://www.eurekalert.org/multimedia/pub/19930.php
Source of image: http://chandra.harvard.edu/photo/2010/sdss/
Source of text:http://www.sciencedaily.com/releases/2010/02/100203131413.htm and http://www.upi.com/Science_News/2010/02/04/Merging-galaxies-create-a-binary-quasar/UPI-13481265307613/
Here is some information about the Sloan Digital Sky Survey:
"The Sloan Digital Sky Survey (SDSS) obtained deep, multi-color images covering more than a quarter of the sky and created 3-dimensional maps containing more than 930,000 galaxies and more than 120,000 quasars. This was accomplished using a dedicated 2.5-meter telescope at Apache Point Observatory, New Mexico, equipped with two powerful special-purpose instruments. The 120-megapixel camera imaged 1.5 square degrees of sky at a time, about eight times the area of the full moon. A pair of spectrographs fed by optical fibers measured spectra of (and hence distances to) more than 600 galaxies and quasars in a single observation. (source:http://www.sdss.org/
If you are interested in viewing some of the deep space objects the Sloan Digital Sky Survey has recorded go to the following website: http://www.sdss.org/gallery/gal_data.html
(A spectrograph (spectrophotometer, spectrometer or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum. source:http://en.wikipedia.org/wiki/Spectrometer )