No sustained enhancement of the X-ray emission at the Galactic center
ATel #6458; Nathalie Degenaar, Mark Reynolds, Jon Miller (Michigan), Jamie Kennea (Penn State), Rudy Wijnands (Amsterdam), Daryl Haggard (Amherst), on behalf of a larger collaboration
on 10 Sep 2014; 14:11 UT
Credential Certification: Nathalie Degenaar (degenaar@umich.edu)
Subjects: Radio, Millimeter, Sub-Millimeter, Infra-Red, X-ray, Gamma Ray, AGN, Black Hole, Soft Gamma-ray Repeater
We report on continued Swift X-ray monitoring observations of the Galactic center region following the detection of a bright X-ray flare (Atel #6456). A new 1 ks Swift/XRT pointing performed on 2014-09-10 (06:52 UT) reveals that the X-ray emission at the position of Sgr A* and the magnetar SGR 1745-29 has returned to the pre-flare level.
From the new observation we measure an unabsorbed 2-10 keV X-ray flux of ~1E-11 erg/cm2/s at the position of Sgr A*/SGR 1745-29, which corresponds to a luminosity of ~8E34 erg/s at a distance of 8 kpc. This is consistent with the pre-flare level, which is largely attributed to X-ray emission from the (slowly fading) magnetar. This suggests that Swift/XRT detected a short-lived X-ray flare and that there are no indications of sustained enhanced X-ray activity. The duration, peak flux and spectral shape of the 2014 flare look very similar to six previous X-ray flares detected from Sgr A* by Swift/XRT (Degenaar et al. 2013, ApJ 769, 155).
XRT monitoring observations of the Galactic center region are ongoing and results are posted promptly at the Swift Sgr A* Monitoring Campaign Website.
