Related papers: Increasing the Scientific Return of Stellar Orbits…
We present improved relative astrometry for stars within the central half parsec of our Galactic Center based on data obtained with the 10 m W. M. Keck Observatory from 1995 to 2017. The new methods used to improve the astrometric precision…
Precision measurements of the stars in short-period orbits around the supermassive black hole at the Galactic Center are now being used to constrain general relativistic effects, such as the gravitational redshift and periapse precession.…
We present significantly improved proper motion measurements of the Milky Way's central stellar cluster. These improvements are made possible by refining our astrometric reference frame with a new geometric optical distortion model for the…
The S-star cluster in the Galactic center allows us to study the physics close to a supermassive black hole, including distinctive dynamical tests of general relativity. Our best estimates for the mass of and the distance to Sgr A* using…
We simulate the astrometric observations of stars moving close to the black hole in the Galactic Center. We show, that for orbits =<1000 AU and position measurements with the accuracy of the Keck Interferometer, the periastron motion of…
We show that high quality laser guide star (LGS) adaptive optics (AO) observations of nearby early-type galaxies are possible when the tip-tilt correction is done by guiding on nuclei while the focus compensation due to the changing…
We present a new stellar dynamical mass measurement of the black hole in the nearby, S0 galaxy NGC 3998. By combining laser guide star adaptive optics observations obtained with the OH-Suppressing Infrared Imaging Spectrograph on the Keck…
We present new, more precise measurements of the mass and distance of our Galaxy's central supermassive black hole, Sgr A*. These results stem from a new analysis that more than doubles the time baseline for astrometry of faint stars…
We report new precision measurements of the properties of our Galaxy's supermassive black hole. Based on astrometric (1995-2007) and radial velocity (2000-2007) measurements from the W. M. Keck 10-meter telescopes, a fully unconstrained…
The Laser Interferometer Space Antenna's (LISA's) observation of supermassive binary black holes (SMBBH) could provide a new tool for precision cosmography. Inclusion of sub-dominant signal harmonics in the inspiral signal allows for…
Recently it was shown that the inclusion of higher signal harmonics in the inspiral signals of binary supermassive black holes (SMBH) leads to dramatic improvements in parameter estimation with the Laser Interferometer Space Antenna (LISA).…
Near-infrared observations of stellar orbits at the Galactic Center provide conclusive evidence for a massive black hole associated with the compact radio source Sgr A*. The astrometric reference frame for these observations is tied to a…
In this paper, we investigate the quality of constraining the spin of the massive black hole (MBH) at the Galactic center (GC) by using full general relativistic simulations of the motion of a surrounding star. We obtain the dependence…
We present the results of 16 years of monitoring stellar orbits around the massive black hole in center of the Milky Way using high resolution NIR techniques. This work refines our previous analysis mainly by greatly improving the…
The supermassive black hole (SMBH) with 4 millions solar mass inside the radio-source Sgr A* in our Galactic center is the nearest SMBH. Once the S stars with shorter period are observed, the relativistic precessions especially the…
The effect of stars on the lensing properties of the supermassive black hole in the Galactic Center is similar to the effect of planets on microlensing by a star. We show that the dense stellar cluster around SgrA* increases by factors of a…
(Abridged) We present the first Laser Guide Star Adaptive Optics (LGS-AO) observations of the Galactic center. LGS-AO has dramatically improved the quality, robustness, and versatility with which high angular resolution infrared images of…
With the advent of adaptive optics on the W. M. Keck 10 m telescope, two significant steps forward have been taken in building the case for a supermassive black hole at the center of the Milky Way and understanding the black hole's effect…
We report on an investigation of the SBS 1520+530 gravitational lens system and its environment using archival HST imaging, Keck spectroscopic data, and Keck adaptive-optics imaging. The AO imaging has allowed us to fix the lens galaxy…
At cosmological distances, gravitational lensing can provide a direct measurement of supermassive black hole (SMBH) masses irrespective of their luminosities. Here, we directly estimate the mass of a SMBH in the brightest cluster galaxy…