HE0450-2958

From Wikipedia, the free encyclopedia

Observation data (Epoch J2000)
HB89 0450-299
Quasar HE0450-2958 as imaged by the HST.
Constellation	Caelum
Right ascension	04^h 52^m 30.0^s^[1]
Declination	-29° 53′ 35″^[1]
Redshift	76,950 ± 20 km/s^[1]
Distance	3 Gly (1 Gpc)^{[citation needed]}
Type	Sy1^[1]
Apparent magnitude (V)	16.0^[1]
Other designations
LEDA 75249^[1]
See also: Quasar, List of quasars
This box: view • talk • edit

HE0450-2958 is an unusual quasar. It is referred to as the Quasar without a Home because no evidence of a massive host galaxy is found. It is estimated to lie 3,000,000,000 light-years away, and have a mass of 400,000,000 Suns.

The researchers announced their findings September 14, 2005. The quasar is neighbouring a gas cloud 2,500 light-years across, christened the blob. This cloud may be feeding the supermassive black hole. In order for the survey to have missed the galaxy, it must be 6 magnitudes dimmer than detectable or have a radius of 300 light-years or less (typical quasars are embedded in galaxies 5000 to 50,000 light-years across). It might be a dark galaxy that was turned into a quasar. It lies 50,000 light-years from a disrupted galaxy undergoing starburst.

A theory has been proposed that the black hole is actually an ejected central black hole of one of two merging galaxies, that merged 100,000 years before into the disrupted galaxy. One of the two merging galaxies previously experienced a merger and had two central black holes. With the addition of a third, the lightest was ejected, dragging along the blob of gas that created the quasar. The quasar appears to be speeding away from the starburst galaxy at 300 km/s.

[edit] See also

[edit] References

Discovery of a bright quasar without a massive host galaxy, Pierre Magain et al. (Nature)
Researchers: Pierre Magain and Géraldine Letawe (Université de Liège, Belgium), Frédéric Courbin and Georges Meylan (Ecole Polytechnique Fédérale de Lausanne, Switzerland), Pascale Jablonka (Ecole Polytechnique Fédérale de Lausanne and Université de Genève, Switzerland) , and Knud Jahnke and Lutz Wisotzki (Astrophysikalisches Institut Potsdam, Germany)