Black hole acts as a cosmic 'Old Faithful.' (astronomers observe regular eruptions of hot matter from suspected black hole GRS 1915+105)(Brief Article)
The link between the X-ray and infrared observations may shed light on the origin of these high-speed jets, which can be seen near many objects thought to be black holes. Astronomers from NASA's Goddard Space Flight Center in Greenbelt, Md., the California Institute of Technology in Pasadena, and the Massachusetts Institute of Technology announced their findings Jan. 7 at a meeting of the American Astronomical Society in Washington, D.C.
In 1994, researchers detected huge blobs of gas, moving at nearly the speed of light, that had been ejected from GRS 1915+105 (SN: 9/3/94, p. 150). Late last year, scientists again observed large amounts of material spewing from the suspected black hole, located about 40,000 light-years from Earth in the constellation Aquila (SN: 12/6/97, p. 357).
Teams from NASA and MIT monitored GRS 1915+105's X-ray emissions for 3 days in August 1997 and found a regular, pronounced dip in output for about 5 minutes of every 30-minute cycle. These fluctuations could occur either if the hot gas generating the X rays is swallowed by the candidate black hole or if the gas somehow escapes GRS 1915+105's intense gravitational field, says Jean H. Swank of NASA.
However, the Caltech team, simultaneously observing GRS 1915+105 at infrared wavelengths, discovered flare-ups that coincided with the dips in X-ray emissions. These infrared outbursts hint that gas is ejected from the region surrounding GRS 1915+105 rather than being swallowed, explains Swank.
The astronomers estimate that each eruption throws off 100 trillion tons of hot gas at a speed of about 650 million miles per hour--about 92 percent the speed of light--carrying 6 trillion times the energy provided by power companies each year in the United States.