Evidence for X-ray synchrotron emission from simultaneous mid-IR to X-ray observations of a strong Sgr A* flare

Abstract

This paper reports measurements of Sgr A* made with NACO in L' -band (3.80 um), Ks-band (2.12 um) and H-band (1.66 um) and with VISIR in N-band (11.88 um) at the ESO VLT, as well as with XMM-Newton at X-ray (2-10 keV) wavelengths. On 4 April, 2007, a very bright flare was observed from Sgr A* simultaneously at L'-band and X-ray wavelengths. No emission was detected using VISIR. The resulting SED has a blue slope (beta > 0 for nuL_nu ~ nu^beta, consistent with nuL_nu ~ nu^0.4) between 12 micron and 3.8 micron. For the first time our high quality data allow a detailed comparison of infrared and X-ray light curves with a resolution of a few minutes. The IR and X-ray flares are simultaneous to within 3 minutes. However the IR flare lasts significantly longer than the X-ray flare (both before and after the X-ray peak) and prominent substructures in the 3.8 micron light curve are clearly not seen in the X-ray data. From the shortest timescale variations in the L'-band lightcurve we find that the flaring region must be no more than 1.2 R_S in size. The high X-ray to infrared flux ratio, blue nuL_nu slope MIR to L' -band, and the soft nuL_nu spectral index of the X-ray flare together place strong constraints on possible flare emission mechanisms. We find that it is quantitatively difficult to explain this bright X-ray flare with inverse Compton processes. A synchrotron emission scenario from an electron distribution with a cooling break is a more viable scenario.

ApJ, 49 pages, 9 figures

References in corpus (14)

• Monitoring stellar orbits around the Massive Black Hole in the Galactic Center
• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• Polarimetry of near-infrared flares from Sagittarius A*
• A near-IR variability study of the Galactic black hole: a red noise source with no detected periodicity
• A Constant Spectral Index for Sagittarius A* During Infrared/X-ray Intensity Variations
• X-ray hiccups from SgrA* observed by XMM-Newton. The second brightest flare and three moderate flares caught in half a day
• A polarised infrared flare from Sagittarius A* and the signatures of orbiting plasma hotspots
• Prospects for testing the nature of Sgr A*'s NIR flares on the basis of current VLT- and future VLTI-observations
• K-band polarimetry of an Sgr A* flare with a clear sub-flare structure
• A 600 minute near-infrared lightcurve of Sagittarius A*
• A Testable the Stochastic Acceleration Model for Flares in Sagittarius A*
• Testing RIAF model for Sgr A* using the size measurements
• Modulated X-ray Emissivity near the Stress Edge in Sgr A*

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