G2 is a cloud on a near-radial orbit about our galaxy's central black hole, Sagittarius A*. In a paper we have submitted to ApJL (ArXiv 1401.2990), we suggest that this cloud may be one of many in a stream of debris that stretches to a nearby giant star.
Below are some movies from a three-dimensional simulation we ran where material removed from a giant star falls onto a black hole. This material is collimated into a thin stream, and radiatively cools in regions of enhanced density. This cooling leads to clumpiness within the returning stream: We propose that one of these clumps is the observed G2 cloud.
New! Isodensity contours, with color showing temperature (red = hot, blue = cold).
Log column density, normal to orbital plane.
Log T, slice through orbital plane.
Log T, cycling through planes directly above and below orbital plane at a fixed time.
Total radiative cooling flux, with resolution degraded to that typical of observations in the galactic center.