Interstellar gas within $\sim 10$ pc of Sgr A$^*$
  We seek to obtain a coherent and realistic three-dimensional picture of the
interstellar gas out to about 10 pc of the dynamical center of our Galaxy,
which is supposed to be at Sgr A$^*$. We review the existing observational
studies on the different gaseous components that have been identified near Sgr
A$^*$, and retain all the information relating to their spatial configuration
and/or physical state. Based on the collected information, we propose a
three-dimensional representation of the interstellar gas, which describes each
component in terms of both its precise location and morphology and its
thermodynamic properties. The interstellar gas near Sgr A$^*$ can represented
by five basic components, which are, by order of increasing size: (1) a central
cavity with roughly equal amounts of warm ionized and atomic gases, (2) a ring
of mainly molecular gas, (3) a supernova remnant filled with hot ionized gas,
(4) a radio halo of warm ionized gas and relativistic particles, and (5) a belt
of massive molecular clouds. While the halo gas fills $\approx 80%$ of the
studied volume, the molecular components enclose $\approx 98%$ of the
interstellar mass.
