# MEASURING DISTANCE AND PROPERTIES OF THE MILKY WAY'S CENTRAL SUPERMASSIVE BLACK HOLE WITH STELLAR ORBITS

@article{Ghez2008MEASURINGDA,
title={MEASURING DISTANCE AND PROPERTIES OF THE MILKY WAY'S CENTRAL SUPERMASSIVE BLACK HOLE WITH STELLAR ORBITS},
author={Andrea M. Ghez and Samir Salim and Nevin N. Weinberg and J. R. Lu and Tuan Do and J. K. Dunn and Keith Y. Matthews and Mark R. Morris and Sylvana Yelda and Eric Edward Becklin and Ted Kremenek and Milos Milosavljevic and Jill Naiman},
journal={The Astrophysical Journal},
year={2008},
volume={689},
pages={1044-1062}
}
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 10m 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±0.6x10^6 M☉ and the black hole's RV, which is consistent with zero with 30 km/s uncertainty. If the black hole is assumed to be… Expand
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#### References

SHOWING 1-10 OF 88 REFERENCES
The accelerations of stars orbiting the Milky Way's central black hole
• Physics, Medicine
• Nature
• 2000
Measurements of the accelerations of three stars from the central radio source Sagittarius A* increase the inferred minimum mass density in the central region of the Galaxy by an order of magnitude relative to previous results, and localize the dark mass to within 0.05 ± 0.04 arcsec of the nominal position of Sgr A*. Expand
A Relationship between Nuclear Black Hole Mass and Galaxy Velocity Dispersion
We describe a correlation between the mass Mbh of a galaxy's central black hole and the luminosity-weighted line-of-sight velocity dispersion σe within the half-light radius. The result is based on aExpand
High Proper-Motion Stars in the Vicinity of Sagittarius A*: Evidence for a Supermassive Black Hole at the Center of Our Galaxy
• Physics
• 1998
Over a 2 year period we have conducted a di†raction-limited imaging study at 2.2 km of the inner 6A ) 6A of the central stellar cluster of the Galaxy using the W. M. Keck 10 m telescope. The K-bandExpand
The Supermassive Black Hole at the Center of the Milky Way
We report the detection of a variable point source, imaged at L' (3.8 μm) with the Keck II 10 m telescope's adaptive optics system, that is coincident to within 18 mas (1 σ) of the Galaxy's centralExpand
Sagittarius A* “Visual Binaries”: A Direct Measurement of the Galactocentric Distance
• Physics
• 1999
We present a new geometrical method for measuring the distance to the Galactic center (R0) by solving for the Keplerian orbit of individual stars bound to the black hole associated with Sgr A* fromExpand
The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy’s Central Black Hole: A Paradox of Youth
We have obtained the first detection of spectral absorption lines in one of the high-velocity stars in the vicinity of the Galaxy's central supermassive black hole. Both Brγ (2.1661 μm) and He IExpand
A star in a 15.2-year orbit around the supermassive black hole at the centre of the Milky Way
Ten years of high-resolution astrometric imaging allow us to trace two-thirds of the orbit of the star currently closest to the compact radio source (and massive black-hole candidate) Sagittarius A* and show that the star is on a bound, highly elliptical keplerian orbit around Sgr A*. Expand
Periastron shifts of stellar orbits near the Galactic Center
• Physics
• 2001
The presence of a $2.9\pm0.4$ million solar mass object in the central stellar cluster of the Milky Way has recently been demonstrated via measurements of the stellar proper motions and radialExpand
Luminous and dark matter in the Milky Way
• Physics
• 2001
Axisymmetric models of the Milky Way exhibit strong interrelations between the Galactic constants [the Sun's distance to the Galactic Centre (R0), and the local rotation speed (θ0)], the localExpand
Stellar proper motions in the central 0.1 PC of the galaxy
• Physics
• 1997
We report the first results of a programme to measure proper motions of stars in the innermost core of the Galaxy. From high-resolution near-infrared imaging over the last four years we haveExpand