Signatures of an Encounter Between the G2 Cloud and a Jet from Sgr A*. (arXiv:1303.3969v1 [astro-ph.HE])

Signatures of an Encounter Between the G2 Cloud and a Jet from Sgr A*. (arXiv:1303.3969v1 [astro-ph.HE]):
The recent discovery of the G2 cloud of dense, ionized gas on a trajectory
toward Sgr A*, the black hole at the dynamical center of the Galaxy, offers a
unique opportunity to observe an accretion event onto a massive black hole as
well as to probe its immediate environment. Simulations and models predict
increased X-ray and radio variability resulting from increased accretion driven
by drag on an atmosphere of hot, X-ray emitting gas surrounding Sgr A*. Here,
we present X-ray and radio light curves of the emission resulting from the
potential encounter of the G2 cloud with a relativistic jet from Sgr A*. This
interaction would violently shock a portion of the G2 cloud to temperatures
~10^8 K resulting in bright X-ray emission from the dense, shocked gas as it
adiabatically expands. The 2-10 keV luminosity may reach ~10 times the
quiescent X-ray flux of Sgr A*. Approximately 3 solar luminosity is emitted
above 10 keV at the peak of the light curve, with significant softening of the
spectrum occurring as the gas subsequently cools. Observations with NuSTAR
would therefore be able to confirm such an event as well as determine the cloud
speed. At radio wavelengths, the associated synchrotron radio emission may
reach levels of a few Jy, although this is more uncertain due to the efficiency
of converting the shock luminosity to that of electrons accelerated to
relativistic energies.