국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Fermi Large Area Telescope Observations of the Supernova Remnant GS.7-0.1
저자	Ajello, M.;; Allafort, A.;; Baldini, L.;; Ballet, J.;; Barbiellini, G.;; Bastieri, D.;; Bechtol, K.;; Bellazzini, R.;; Berenji, B.;; Blandford, R. D.;; Bloom, E. D.;; Bonamente, E.;; Borgland, A. W.;; Bregeon, J.;; Brigida, M.;; Bruel, P.;; Buehler, R.;; Buson, S.;; Caliandro, G. A.;; Cameron, R. A.;; Ferrara, E. C.;; Harding, A. K.;; Hays, E.;; Moiseev, A. A.;; Troja, E.
Keyword	COSMIC RAYS;; GAMMA RAY SPECTRA;; PARTICLE ACCELERATION;; PARTICLE DIFFUSION;; PARTICLE ENERGY;; PHOTONS;; RADIO EMISSION;; SPACEBORNE TELESCOPES;; SPECTRA;; SUPERNOVA REMNANTS;; TELESCOPES
URL	http://hdl.handle.net/2060/20110023494
보고서번호	GSFC.JA.5424.2011
발행년도	2011
출처	NTRS (NASA Technical Report Server)
ABSTRACT	We present a detailed analysis of the GeV gamma-ray emission toward the supernova remnant (SNR) G8.7-0.1 with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. An investigation of the relationship among G8.7-0.l and the TeV unidentified source HESS J1804-216 provides us with an important clue on diffusion process of cosmic rays if particle acceleration operates in the SNR. The GeV gamma-ray emission is extended with most of the emission in positional coincidence with the SNR G8.7-0.l and a lesser part located outside the western boundary of G8.7-0.l. The region of the gamma-ray emission overlaps spatially-connected molecular clouds, implying a physical connection for the gamma-ray structure. The total gamma-ray spectrum measured with LAT from 200 MeV-100 GeV can be described by a broken power-law function with a break of 2.4 +/- 0.6 (stat) +/- 1.2 (sys) GeV, and photon indices of 2.10 +/- 0.06 (stat) +/- 0.10 (sys) below the break and 2.70 +/- 0.12 (stat) +/- 0.l4 (sys) above the break. Given the spatial association among the gamma rays, the radio emission of G8.7-0.1, and the molecular clouds, the decay of 1IoS produced by particles accelerated in the SNR and hitting the molecular clouds naturally explains the GeV gamma-ray spectrum. We also find that the GeV morphology is not well represented by the TeV emission from HESS J1804-216 and that the spectrum in the GeV band is not consistent with the extrapolation of the TeV gamma-ray spectrum. The spectral index of the TeV emission is consistent with the particle spectral index predicted by a theory that assumes energy-dependent diffusion of particles accelerated in an SNR. We discuss the possibility that the TeV spectrum originates from the interaction of particles accelerated in G8.7-0.1 with molecular clouds, and we constrain the diffusion coefficient of the particles.