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Cited by 1,577Astrophysical Phenomena and ObservationsStellar, planetary, and galactic studiesGalaxies: Formation, Evolution, Phenomena

Measuring Distance and Properties of the Milky Way’s Central Supermassive Black Hole with Stellar Orbits

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Ghez, A. M., Salim, S., Weinberg, N. N., Lu, J. R., Do, T., Dunn, J. K., Matthews, K., Morris, M. R. +5 more·2008·The Astrophysical Journal
DOI 10.1086/592738
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Abstract

We report new precision measurements of the properties of our Galaxy's supermassive black hole. Based on astrometric (1995-2007) and radial velocity (RV; 2000-2007) measurements from the W. M. Keck 10 m telescopes, a fully unconstrained Keplerian orbit for the short-period star S0-2 provides values for the distance ( R 0 ) of 8.0 ± 0.6 kpc, the enclosed mass ( M bh ) of 4.1 ± 0.6 × 10 6 M ☉ , and the black hole's RV, which is consistent with zero with 30 km s −1 uncertainty. If the black hole is assumed to be at rest with respect to the Galaxy (e.g., has no massive companion to induce motion), we can further constrain the fit, obtaining R 0 = 8.4 ± 0.4 kpc and M bh = 4.5 ± 0.4 × 10 6 M ☉ . More complex models constrain the extended dark mass distribution to be less than 3-4 × 10 5 M ☉ within 0.01 pc, ~100 times higher than predictions from stellar and stellar remnant models. For all models, we identify transient astrometric shifts from source confusion (up to 5 times the astrometric error) and the assumptions regarding the black hole's radial motion as previously unrecognized limitations on orbital accuracy and the usefulness of fainter stars. Future astrometric and RV observations will remedy these effects. Our estimates of R 0 and the Galaxy's local rotation speed, which it is derived from combining R 0 with the apparent proper motion of Sgr A*, (θ 0 = 229 ± 18 km s −1 ), are compatible with measurements made using other methods. The increased black hole mass found in this study, compared to that determined using projected mass estimators, implies a longer period for the innermost stable orbit, longer resonant relaxation timescales for stars in the vicinity of the black hole and a better agreement with the M bh -σ relation.

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  1. REFERENCES Be ´langer, G., Terrier, R., de Jager, O. C., Goldwurm, A., & Melia, F. 2006, J. Phys. Conf. Ser., 54, 420 ---. 2008, ApJ, submitted
  2. Do, T., Ghez, A. M., Morris, M. R., Yelda, S., Lu, J. R., Hornstein, S., & Matthews, K. 2008, ApJ, in press (arXiv:0810.0446) · arXiv
  3. Hornstein, S. D. 2007, Ph.D. thesis, UCLA
  4. Lu, J. R., Ghez, A. M., Hornstein, S. D., Morris, M., Matthews, K., Thompson, D. J., & Becklin, E. E. 2006, J. Phys. Conf. Ser., 54, 279
  5. ---. 2008, ApJ, in press (arXiv:0808.3818) · arXiv
  6. McLean, I. S., Graham, J. R., Becklin, E. E., Figer, D. F., Larkin, J. E., Levenson, N. A., & Teplitz, H. I. 2000, Proc. SPIE, 4008, 1048
  7. McLean, I. S., et al. 1998, Proc. SPIE, 3354, 566
  8. Nikiforov, I. I. 2008, in Dynamics of Galaxies, in press (arXiv:0803.0825) · arXiv
  9. Weinberg, S. 1972, Gravitation and Cosmology: Principles and Applications of the General Theory of Relativity ( New York: Wiley)
  10. Wizinowich, P. L., Acton, D. S., Lai, O., Gathright, J., Lupton, W., & Stomski, P. J. 2000, Proc. SPIE, 4007, 2

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Authors
Ghez, A. M., Salim, S., Weinberg, N. N., Lu, J. R., Do, T., Dunn, J. K., Matthews, K., Morris, M. R., Yelda, S., Becklin, E. E., Kremenek, T., Milosavljevic, M., & Naiman, J.
Affiliations
  • University of California, Los Angeles (US)
  • California Institute of Technology (US)
  • The University of Texas at Austin (US)
ORCID
Venue
The Astrophysical Journal
Publisher
American Astronomical Society
Published
2008-12-20
Volume
689
Issue
2
Pages
1044-1062
ISSN
  • 0004-637X (ISSN-L)
  • 1538-4357
DOI
10.1086/592738
OpenAlex
W2100306218
Cited by
1,577
References
73
Citations by year
2026: 69 · 2025: 89 · 2024: 83 · 2023: 77 · 2022: 75 · 2021: 89 · 2020: 75 · 2019: 72 · 2018: 84 · 2017: 67 · 2016: 115 · 2015: 88 · 2014: 105 · 2013: 125 · 2012: 105
FWCI
49.58
Type
journal article
Language
en
Open access
Locations
  • The Astrophysical Journal (publishedVersion)
  • arXiv (Cornell University) (submittedVersion)
  • CaltechAUTHORS (California Institute of Technology) (submittedVersion)
  • arXiv (Cornell University)
Funders
  • National Science Foundation (0406816)
  • National Aeronautics and Space Administration
  • W. M. Keck Foundation
  • California Institute of Technology
Topics
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Astrophysical Phenomena and Observations
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Stellar, planetary, and galactic studies
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Galaxies: Formation, Evolution, Phenomena
Keywords
supermassive black holes, Sgr A*, Milky Way center, black hole mass, galactocentric distance, Keplerian orbits, stellar orbits, proper motions, innermost stable circular orbit, MBH-sigma relation, resonant relaxation, source confusion

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