Breann N. Sitarski

AN IMPROVED DISTANCE AND MASS ESTIMATE FOR SGR A* FROM A MULTISTAR ORBIT ANALYSIS

We present new, more precise measurements of the mass and distance of our Galaxys 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 orbiting Sgr A*, combining two decades of speckle imaging and adaptive optics data. Specifically, we improve our analysis of the speckle images by using information about a stars orbit from the deep adaptive optics data (2005 - 2013) to inform the search for the star in the speckle years (1995 - 2005). When this new analysis technique is combined with the first complete re-reduction of Keck Galactic Center speckle images using speckle holography, we are able to track the short-period star S0-38 (K-band magnitude = 17, orbital period = 19 years) through the speckle years. We use the kinematic measurements from speckle holography and adaptive optics to estimate the orbits of S0-38 and S0-2 and thereby improve our constraints of the mass (

Detection of Galactic Center source G2 at 3.8 μm during periapse passage

M_{bh}

THE HYPERACTIVE L DWARF 2MASS J13153094–2649513: CONTINUED EMISSION AND A BROWN DWARF COMPANION*

) and distance (

A New Distortion Solution for NIRC2 on the Keck II Telescope

R_o

Modeling anisoplanatism in the Keck II laser guide star AO system

) of Sgr A*:

The Post-periapsis Evolution of Galactic Center Source G1: The Second Case of a Resolved Tidal Interaction with a Supermassive Black Hole

M_{bh} = 4.02\pm0.16\pm0.04\times10^6~M_{\odot}

Point spread function determination for Keck adaptive optics

and

Modeling instrumental field-dependent aberrations in the NIRC2 instrument on the Keck II telescope

7.86\pm0.14\pm0.04

Constraining the Variability and Binary Fraction of Galactic Center Young Stars

kpc. The uncertainties in

The late-type stellar density profile in the Galactic Center: A statistical approach

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