Abstract
The radio source Sagittarius A* at the center of our Galaxy is believed to be a 2.6 x 106 M⊙ black hole that accretes gas from the winds of nearby stars. We show that limits on the X-ray and infrared emission from the Galactic center provide an upper limit of ∼8 x 10-5 M⊙ yr- on the mass accretion rate in Sgr A*. The advection-dominated accretion flow (ADAF) model favors a rate of ≲10-5 M⊙ yr-1. In comparison, the Bondi accretion rate onto Sgr A*, estimated using the observed spatial distribution of mass-losing stars and assuming noninteracting stellar winds, is ∼3 x 10-5 M⊙ yr-1. Thus, there is rough agreement between the Bondi, the ADAF, and the X-ray-inferred accretion rates for Sgr A*. We discuss uncertainties in these estimates, emphasizing the importance of upcoming observations by the Chandra X-ray Observatory for tightening the X-ray-derived limits.
Original language | English (US) |
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Pages (from-to) | L101-L104 |
Journal | Astrophysical Journal |
Volume | 517 |
Issue number | 2 PART 2 |
DOIs | |
State | Published - Jun 1 1999 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
Keywords
- Accretion, accretion disks
- Black hole physics
- Galaxy: center