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%astro-ph/0711.4626


\documentstyle{article}
\begin{document}

\title{Constraints on jet-driven disk accretion in Sagittarius
  A$^\star$}

\author{Erin J. D. Jolley and Zdenka Kuncic}

\affil{School of Physics, University of Sydney,
   Sydney NSW, Australia}
\maketitle
\begin{abstract}
We revisit theoretical and observational constraints on geometrically-thin
disk accretion in
Sagittarius\,A$^\star$ (Sgr A*). We show that the combined effects of
mass outflows and electron energization in the hot part
of the accretion flow can deflate the inflowing gas from a
geometrically-thick structure. This allows the gas
to cool and even thermalize on an inflow timescale. As a result, a compact,
relatively cool disk may form at small radii. We show that magnetic
coupling
between the relativistic disk and a steady-state jet results in a
disk that is less luminous than a standard relativistic disk accreting at
the same rate.
This relaxes the observational constraints on
thin-disk accretion in Sgr A* (and by implication, other Low-Luminosity
Active Galactic
Nulcei, LLAGN).
We find typical cold gas accretion rates of
$\mbox{a few} \times 10^{-9} M_\odot \, {\rm yr}^{-1}$.
We also find that the predicted modified disk emission is
compatible with existing near-infrared (NIR) observations of Sgr A* in
its quiescent state provided that the disk
inclination angle is $\gtapprox 87^\circ$ and that the jet extracts
more than $75$\% of the accretion power.
\end{abstract}

\end{document}

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