EVIDENCE FOR A SECOND COMPONENT IN THE HIGH-ENERGY CORE EMISSION FROM CENTAURUS A?

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	EVIDENCE FOR A SECOND COMPONENT IN THE HIGH-ENERGY CORE EMISSION FROM CENTAURUS A?
	Sahakyan, N.1,2; Yang, R.3; Aharonian, F. A.4; Rieger, F. M.5
刊名	ASTROPHYSICAL JOURNAL LETTERS
	2013-06-10
卷号	770 期号:1 页码:0
关键词	galaxies: active galaxies: individual (Cen A)
ISSN号	2041-8205
通讯作者	Sahakyan, N (reprint author), ICRANet, Piazz Repubbl 10, I-65122 Pescara, Italy. Email: 0
英文摘要	We report on an analysis of Fermi Large Area Telescope data from four years of observations of the nearby radio galaxy Centaurus A (Cen A). The increased photon statistics results in a detection of high-energy (>100 MeV) gamma-rays up to 50 GeV from the core of Cen A, with a detection significance of about 44 sigma. The average gamma-ray spectrum of the core reveals evidence for a possible deviation from a simple power law. A likelihood analysis with a broken power-law model shows that the photon index becomes harder above E-b similar or equal to 4 GeV, changing from Gamma(1) = 2.74 +/- 0.03 below to Gamma(2) = 2.09 +/- 0.20 above. This hardening could be caused by the contribution of an additional high-energy component beyond the common synchrotron self-Compton jet emission. No clear evidence for variability in the high-energy domain is seen. We compare our results with the spectrum reported by H.E.S.S. in the TeV energy range and discuss possible origins of the hardening observed.
学科主题	Physics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	LARGE-AREA TELESCOPE ; GAMMA-RAY EMISSION ; RADIO GALAXY CENTAURUS ; BLACK-HOLE ; NGC 5128 ; JET ; RADIATION ; CATALOG ; M87
收录类别	SCI
语种	英语
WOS记录号	WOS:000319723500006
公开日期	2014-01-08
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/9768]
专题	紫金山天文台_暗物质和空间天文实验室
作者单位	1.ICRANet, I-65122 Pescara, Italy 2.NAS Armenia, Inst Phys Res, Ashtarak 2, Armenia 3.Chinese Acad Sci, Key Lab Dark Matter & Space Astron, Purple Mt Observ, Nanjing 210008, Peoples R China 4.Dublin Inst Adv Studies, Dublin 2, Ireland 5.Max Planck Inst Kernphys, D-69029 Heidelberg, Germany
推荐引用方式 GB/T 7714	Sahakyan, N.,Yang, R.,Aharonian, F. A.,et al. EVIDENCE FOR A SECOND COMPONENT IN THE HIGH-ENERGY CORE EMISSION FROM CENTAURUS A?[J]. ASTROPHYSICAL JOURNAL LETTERS,2013,770(1):0.
APA	Sahakyan, N.,Yang, R.,Aharonian, F. A.,&Rieger, F. M..(2013).EVIDENCE FOR A SECOND COMPONENT IN THE HIGH-ENERGY CORE EMISSION FROM CENTAURUS A?.ASTROPHYSICAL JOURNAL LETTERS,770(1),0.
MLA	Sahakyan, N.,et al."EVIDENCE FOR A SECOND COMPONENT IN THE HIGH-ENERGY CORE EMISSION FROM CENTAURUS A?".ASTROPHYSICAL JOURNAL LETTERS 770.1(2013):0.