EVIDENCE FOR X-RAY SYNCHROTRON EMISSION FROM SIMULTANEOUS MID-INFRARED TO X-RAY OBSERVATIONS OF A STRONG Sgr A* FLARE

	*EVIDENCE FOR X-RAY SYNCHROTRON EMISSION FROM SIMULTANEOUS MID-INFRARED TO X-RAY OBSERVATIONS OF A STRONG Sgr A FLARE**
	Dodds-Eden, K.1; Porquet, D.2; Trap, G.3,4; Quataert, E.5; Haubois, X.6; Gillessen, S.1; Grosso, N.2; Pantin, E.3,7; Falcke, H.8,9; Rouan, D.6
刊名	ASTROPHYSICAL JOURNAL
	2009-06-10
卷号	698 期号:1 页码:676-692
关键词	accretion black hole physics Galaxy: center infrared: general radiation mechanisms: general X-rays: general accretion disks
英文摘要	This paper reports measurements of Sgr A* made with NACO in L' band (3.80 mu m), Ks band (2.12 mu m), and H band (1.66 mu m), and with VISIR in N band (11.88 mu m) at the ESO VLT, as well as with XMM-Newton at X-ray (2-10 keV) wavelengths. On 2007 April 4, 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 spectral energy distribution has a blue slope (beta > 0 for nu L-nu proportional to nu(beta), consistent with nu L-nu proportional to nu(0.4)) between 12 mu m and 3.8 mu m. For the first time, our high-quality data allow a detailed comparison of infrared (IR) 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 mu m light curve are clearly not seen in the X-ray data. From the shortest timescale variations in the L'-band light curve, we find that the flaring region must be no more than 1.2R(S) in size. The high X-ray to IR flux ratio, blue nu L-nu slope MIR to L'band, and the soft nu L-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.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	SUPERMASSIVE BLACK-HOLE ; NEAR-INFRARED FLARES ; SAGITTARIUS-A ; GALACTIC-CENTER ; ACCRETION FLOW ; STELLAR ORBITS ; RADIO-SOURCE ; XMM-NEWTON ; MILKY-WAY ; MODEL
收录类别	SCI
语种	英语
WOS记录号	WOS:000266373700058
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/19565]
专题	上海天文台_星系宇宙学重点实验室
作者单位	1.Max Planck Inst Extraterr Phys, D-85741 Garching, Germany 2.Univ Strasbourg, CNRS, INSU, Observ Astron Strasbourg, F-67000 Strasbourg, France 3.CEA, IRFU, Serv Astrophys, Ctr Saclay, F-91191 Gif Sur Yvette, France 4.APC, F-75205 Paris, France 5.Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA 6.Univ Paris Diderot, UPMC, CNRS, Observ Paris,LESIA, F-92190 Meudon, France 7.CEA, Ctr Saclay, Lab AIM, F-91191 Gif Sur Yvette, France 8.Radboud Univ Nijmegen, Inst Math Astrophys & Particle Phys, Dept Astrophys, NL-6500 GL Nijmegen, Netherlands 9.ASTRON, NL-7991 PD Dwingeloo, Netherlands 10.Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA
推荐引用方式 GB/T 7714	Dodds-Eden, K.,Porquet, D.,Trap, G.,et al. EVIDENCE FOR X-RAY SYNCHROTRON EMISSION FROM SIMULTANEOUS MID-INFRARED TO X-RAY OBSERVATIONS OF A STRONG Sgr A* FLARE[J]. ASTROPHYSICAL JOURNAL,2009,698(1):676-692.
APA	Dodds-Eden, K..,Porquet, D..,Trap, G..,Quataert, E..,Haubois, X..,...&Mascetti, L..(2009).EVIDENCE FOR X-RAY SYNCHROTRON EMISSION FROM SIMULTANEOUS MID-INFRARED TO X-RAY OBSERVATIONS OF A STRONG Sgr A* FLARE.ASTROPHYSICAL JOURNAL,698(1),676-692.
MLA	Dodds-Eden, K.,et al."EVIDENCE FOR X-RAY SYNCHROTRON EMISSION FROM SIMULTANEOUS MID-INFRARED TO X-RAY OBSERVATIONS OF A STRONG Sgr A* FLARE".ASTROPHYSICAL JOURNAL 698.1(2009):676-692.