Daryl Haggard (CIERA Fellow, Northwestern University ) Thursday June 26th - 11am IPAG Seminar Room - IPAG
The enigmatic object G2 (is it a gas cloud or a star ?) has passed pericenter in its encounter with Sgr A*. G2’s highly eccentric orbit brought it within 150 AU of Sgr A*, and IR monitoring has revealed signs of tidal disruption by the black hole. High-energy emission from the Sgr A*/G2 encounter was expected to rise toward pericenter (Spring 2014) and continue over several years as the material circularized, but no clear changes in Sgr A*’s X-ray or radio emission have yet been detected. Continued multiwavelength monitoring will determine the nature of the G2 object. These ambitious campaigns are also poised to distinguish the physical processes that underlie rapid flares originating near the black hole’s event horizon, including the brightest X-ray flare yet recorded in recent Chandra and VLA observations. The appearance of a new magnetar (SGR J174540.2-290029, 2.4’ from Sgr A*) and an outburst from a very faint X-ray binary (CXO J174540.0-290005) are also yielding new Galactic Center science. I will present an update on our intensive multiwavelength campaigns and discuss the constraints these data place on theoretical models for the Sgr A*/G2 encounter and Sgr A*’s X-ray flares.
Dans la même rubrique :