Galactic Center Research: Manifestations of the Central Black Hole
  This review summarizes a few of the frontiers of Galactic center research
that are currently the focus of considerable activity and attention. It is
aimed at providing a necessarily incomplete sketch of some of the timely work
being done on phenomena taking place in, or originating in, the central few
parsecs of the Galaxy, with particular attention to topics related to the
Galactic black hole (GBH). We have chosen to expand on the following exciting
topics: 1) the characterization and the implications for the variability of
emission from the GBH, 2) the strong evidence for a powerful X-ray flare in the
Galactic center within the past few hundred years, and the likelihood that the
GBH is implicated in that event, 3) the prospects for detecting the "shadow" of
the GBH, 4) an overview of the current state of research on the central S-star
cluster, and what has been learned from the stellar orbits within that cluster,
and 5) the current hypotheses for the origin of the G2 dust cloud that is
projected to make a close passage by the GBH in 2013.
