Testing properties of the Galactic center black hole using stellar orbits

David Merritt, Tal Alexander, Seppo Mikkola, and Clifford M. Will
Phys. Rev. D 81, 062002 – Published 12 March 2010

Abstract

The spin and quadrupole moment of the supermassive black hole at the Galactic center can in principle be measured via astrometric monitoring of stars orbiting at milliparsec distances, allowing tests of general relativistic “no-hair”theorems [23]. One complicating factor is the presence of perturbations from other stars, which may induce orbital precession of the same order of magnitude as that due to general relativistic effects. The expected number of stars in this region is small enough that full N-body simulations can be carried out. We present the results of a comprehensive set of such simulations, which include a post-Newtonian treatment of spin-orbit effects. A number of possible models for the distribution of stars and stellar remnants are considered. We find that stellar perturbations are likely to obscure the signal due to frame dragging for stars beyond 0.5mpc from the black hole, while measurement of the quadrupole moment is likely to require observation of stars inside 0.2mpc. A high fraction of stellar remnants, e.g. 10M black holes, in this region would make tests of general relativity problematic at all radii. We discuss the possibility of separating the effects of stellar perturbations from those due to general relativity.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
2 More
  • Received 25 November 2009

DOI:https://doi.org/10.1103/PhysRevD.81.062002

©2010 American Physical Society

Authors & Affiliations

David Merritt*

  • Department of Physics and Center for Computational Relativity and Gravitation, Rochester Institute of Technology, Rochester, New York 14623, USA

Tal Alexander

  • Faculty of Physics, Weizmann Institute of Science, POB 26, Rehovot, Israel

Seppo Mikkola

  • Tuorla Observatory, University of Turku, Väisäläntie 20, Piikkiö, Finland

Clifford M. Will§

  • McDonnell Center for the Space Sciences, Department of Physics, Washington University, St. Louis, Missouri 63130, USA

  • *merritt@astro.rit.edu
  • tal.alexander@weizmann.ac.il
  • mikkola@utu.fi
  • §cmw@wuphys.wustl.edu

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 81, Iss. 6 — 15 March 2010

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review D

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×