MONITORING STELLAR ORBITS AROUND THE MASSIVE BLACK HOLE IN THE GALACTIC CENTER

By S. Gillessen, F. Eisenhauer, S. Trippe, T. Alexander, R. Genzel, F. Martins, T. Ott. 2008

1,278 citations recorded by the source corpus.

We present the results of 16 years of monitoring stellar orbits around the massive black hole in the center of the Milky Way, using high-resolution near-infrared techniques. This work refines our previous analysis mainly by greatly improving the definition of the coordinate system, which reaches a long-term astrometric accuracy of ≈300 μas, and by investigating in detail the individual systematic error contributions. The combination of a long-time baseline and the excellent astrometric accuracy of adaptive optics data allows us to determine orbits of 28 stars, including the star S2, which has completed a full revolution since our monitoring began. Our main results are: all stellar orbits are fit extremely well by a single-point-mass potential to within the astrometric uncertainties, which are now ≈6× better than in previous studies. The central object mass is , where the fractional statistical error of 1.5% is nearly independent from R0, and the main uncertainty is due to the uncertainty in R0. Our current best estimate for the distance to the Galactic center is R0 = 8.33 ± 0.35 kpc. The dominant errors in this value are systematic. The mass scales with distance as (3.95 ± 0.06) × 106(R0/8 kpc)2.19M☉. The orientations of orbital angular momenta for stars in the central arcsecond are random. We identify six of the stars with orbital solutions as late-type stars, and six early-type stars as members of the clockwise-rotating disk system, as was previously proposed. We constrain the extended dark mass enclosed between the pericenter and apocenter of S2 at less than 0.066, at the 99% confidence level, of the mass of Sgr A*. This is two orders of magnitudes larger than what one would expect from other theoretical and observational estimates.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/0bf5b651376ab590665a6e072f1e35f059eee67f

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Citations in the corpus

Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets (2013, background): “…holes (McClintock & Remillard 2006; ¨Ozel et al. 2010; Orosz et al. 2011a; Steeghs et al. 2013), as well as for several super-massive black holes, e.g., Sgr A* (Ghez et al. 2008; Gillessen et al. 2009), NGC 4258 (Herrnstein et al. 2005), and others (G¨ultekin et al. 2009, and references therein).”
Stellar Dynamics and Stellar Phenomena Near a Massive Black Hole (2017, background): “Sgr A?, the M• ' 4 × 106 M MBH at the center of the Milky Way, R0 ' 8 kpc from the Solar system (Gillessen et al. 2009; Boehle et al. 2016), is the nearest MBH to us.”
Mass models of the Milky Way (2011, methodology): “The corresponding value of v0, 239.2 ± 4.8 kms−1, has a significantly smaller uncertainty than simply combining the Gillessen et al. (2009) value of R0 and the Reid & Brunthaler (2004) value of µSgrA∗ gives, primarily because of the tighter constraints on R0.”
AN EXTREMELY TOP-HEAVY INITIAL MASS FUNCTION IN THE GALACTIC CENTER STELLAR DISKS (2009, background): “The brighter members of this central cusp are spectroscopically identified as main sequence B stars (Ghez et al. 2003; Eisenhauer et al. 2005; Martins et al. 2008; Gillessen et al. 2009).”
RADIATIVE MODELS OF SGR A* FROM GRMHD SIMULATIONS (2009, background): “Recent estimates of Sgr A*’s mass M = 4.5 ± 0.4 × 106 M and distance D = 8.4 ± 0.4 kpc (Ghez et al. 2008; Gillessen et al. 2009) indicate that it has the largest angular size of any known BH (GM/(c2D) 5.3 μas).”
EVIDENCE FOR LOW BLACK HOLE SPIN AND PHYSICALLY MOTIVATED ACCRETION MODELS FROM MILLIMETER-VLBI OBSERVATIONS OF SAGITTARIUS A* (2010, background): “These have yieldedM = 4.3± 0.5× 106M⊙ and D = 8.3± 0.4kpc, respectively, where both include thesystematicuncertainties (Ghez et al. 2008; Gillessen et al. 2009b,a).”
Greatly Enhanced Merger Rates of Compact-object Binaries in Non-spherical Nuclear Star Clusters (2017, background): “Most NCs are believed to host a central massive black hole (MBH); this is the case for the Milky Way, the location of a ∼ 3 × 107M⊙ NC (Schödel et al. 2014, 2017) and a ≈ 4 × 106M⊙ MBH (Ghez et al. 2008; Gillessen et al. 2009).”
PHOTON RINGS AROUND KERR AND KERR-LIKE BLACK HOLES (2013, methodology): “Using the measurements of the mass and distance of Sgr A* from the monitoring of close stellar orbits (Ghez et al. 2008; Gillessen et al. 2009), Broderick et al. (2009a, 2011a) combined the VLBI observations of Sgr A* with measurements of its spectral energy distribution (Yuan et al. 2004 and…”
Double-Disk Dark Matter (2013, background): “The Earth sits about 10 to 20 parsecs above the galactic plane [111] and about 8 kpc from the galactic center [112, 113].”
THE TRIGONOMETRIC PARALLAX OF CYGNUS X-1 (2011, background): “…the distance of the Sun from the Galactic center to be R0 = 8.25 kpc as a rounded average of the values quoted by Reid (1993) for a variety of “classical” techniques and by Ghez et al. (2008) and Gillessen et al. (2009) from the orbits of stars about the supermassive BH at the Galactic center.”
Testing black hole candidates with electromagnetic radiation (2015, background): “Much work in this direction was done by Genzel and his group (Genzel et al., 1997, 1996; Gillessen et al., 2009; Schödel et al., 2002).”
STELLAR POPULATIONS IN THE CENTRAL 0.5 pc OF THE GALAXY. II. THE INITIAL MASS FUNCTION (2013, background): “…of the Galaxy can be divided into several different kinematic sub-groups (Paumard et al. 2006; Ghez et al. 2008; Lu et al. 2009; Bartko et al. 2009; Gillessen et al. 2009b), it is not yet clear whether these sub-groups have different origins, or whether all the young stars formed from the same…”
Rotation Curve and Mass Distribution in the Galactic Center - From Black Hole to Entire Galaxy (2013, positive): “Here we use a black hole mass of MBH = 4 × 106M⊙, taking the mean of the recent values converted to the case for R0 = 8.0 kpc, i.e., 2.6− 4.4× 106M⊙ (Genzel et al. 2000, 2010), 4.1− 4.3× 106M⊙ (Ghez et al. 2005), and 3.95× 106M⊙ (Gillessen et al. 2009).”
THE MILKY WAY'S CIRCULAR-VELOCITY CURVE BETWEEN 4 AND 14 kpc FROM APOGEE DATA (2012, methodology): “The most direct measurement of this kind is the combination of the precisely measured proper motion of Sgr A∗ (Reid & Brunthaler 2004) with the distance to the Galactic center determined from the Keplerian orbits of S stars in the innermost parsec (Ghez et al. 2008; Gillessen et al. 2009).”