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From: Tal Alexander  tal.alexander@weizmann.ac.il 
To: gcnews@aoc.nrao.edu
Subject: submit Zucker05.tex 2005, ApJL, submitted

%astro-ph/0509105
\documentclass[english]{emulateapj}

\begin{document}

\title{Probing Post-Newtonian Gravity near the Galactic Black Hole\\
 with Stellar Doppler Measurements}


\author{Shay Zucker\affil{1}, Tal Alexander\affil{1,2}, Stefan
Gillessen\affil{3}, Frank Eisenhauer\affil{3} and
Reinhard Genzel\affil{3} }

Box 26, Rehovot 76100, Israel} \inst{2}{The William Z. \& Eda 
Bess Novick career development
chair} \inst{3}{Max-Planck-Institut f\"{u}r extraterrestriche 
Physik,
Postfach 1312, Garching D-85741, Germany}

\begin{abstract}
Stars closely approaching the massive black hole in the center of
the Galaxy provide a unique opportunity to probe post-Newtonian physics
in a yet unexplored regime of celestial mechanics. Recent advances
in infrared stellar spectroscopy allow the precise measurement of
stellar Doppler shift curves and thereby the detection of $\beta^{2}$
post-Newtonian effects (gravitational redshift in the black hole's
potential and the transverse Doppler shift). We formulate a detection
procedure in terms of a simplified post-Newtonian parametrization.
We then use simulations to show that these effects can be decisively
detected with existing instruments after about a decade of observations.
We find that neglecting these effects can lead to statistically significant
systematic errors in the derived black hole mass and distance.
\end{abstract}

\end{document}

-- 
Tal Alexander
Faculty of Physics, Weizmann Institute of Science
PO Box 26, Rehovot 76100, Israel
Phone ++972-8-934-4483, Fax ++972-8-934-4477
Email tal.alexander@weizmann.ac.il