  We carry out a series of simulations of G2-type clouds interacting with the
black hole at the galactic center, to determine why no large changes in the
luminosity of Sgr A* were seen, and to determine the nature of G2. We measure
the accretion rate from the gas cloud onto Sgr A* for a range of simulation
parameters, such as cloud structure, background structure, background density,
grid resolution, and accretion radius. For a broad range of parameters, the
amount of cloud material accreted is small relative to the amount of background
material accreted. The total accretion rate is not significantly effected for
at least 30 years after periapsis. We find that reproducing observations of G2
likely requires two components for the object: an extended, cold gas cloud
responsible for the Br-gamma emission, and a compact core or dusty stellar
object dominating the bolometric luminosity. In simulations, the bolometric and
X-ray luminosity have a peak lasting from about 1 year before to 1 year after
periapsis, a feature not detected in observations. Our simulated Br-gamma
emission is largely consistent with observations leading up to periapsis, with
a slight increase in luminosity and a large increase in the FWHM of the line
velocity. All emission from a gaseous component of G2 should fade rapidly after
periapsis and be undetectable after 1 year, due to shock heating and expansion
of the cloud. Any remaining emission should be from the compact component of
G2.
