On The Nature of the Compact Dark Mass at the Galactic Center

نویسندگان

  • Avery E. Broderick
  • Ramesh Narayan
چکیده

We consider a model in which Sgr A*, the 3.5×10M⊙ supermassive black hole candidate at the Galactic Center, is a compact object with a surface. Given the very low quiescent luminosity of Sgr A* in the near infrared, the existence of a hard surface, even in the limit in which the radius approaches the horizon, places severe constraints upon the steady mass accretion rate in the source, requiring Ṁ . 10 M⊙yr . This limit is well below the minimum accretion rate needed to power the observed submillimeter luminosity of Sgr A*. We thus argue that Sgr A* does not have a surface, i.e., it must have an event horizon. The argument could be made more restrictive by an order of magnitude with μas resolution imaging, e.g., with submillimeter VLBI. Subject headings: Galaxy: center—submillimeter—infrared: general—black hole physics—accretion, accretion disks—gravitational lensing

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تاریخ انتشار 2006