(Yamaguchi & Takahara 2012, submitted) 大阪大学山口正輝共同研究者：高原文郎 GCOE研究集会「Multi-Messenger Astronomyで迫るコンパクト天体」 I. II. III. IV. Gamma-ray binary, LS5039 GeV break problem Model with a soft X-ray source Summary • Gamma-rays vary with orbital period Objects Period Scale LS 5039 3.9d 5x10^12cm O + ?? (BH or NS) LS I +61° 303 26d 10^13cm Be + ?? PSR B1259-63 3.4yr 10^14cm Be + NS HESS J0632+057 320d 10^14cm Be + ?? 10^13cm O + ?? 1FGL J1018.6-5856 16d Consists of … • Gamma-rays are detected as flares Cyg X-1 5.6d 3x10^12cm O + BH Cyg X-3 4.8hr 5x10^11cm WR + ??(BH or NS)  Candidate: AGL J2241+4454 (HD 215227(Be)) superior inferior F. Aharonian, et al., 2006, A&A, 460, 743 A. A. Abdo, et al., 2009, ApJL, 706, 56 T. Takahashi, et al., 2009, ApJ, 697, 592 Fermi HESS INFC SUPC Suzaku HESS SUPC Fermi MS INFC Suzaku Photon energy (eV) Phase-averaged spectra Orbital phase Light curves ・TeV & GeV anticorrelate ・TeV & X correlate ・spectral break at ~1 GeV  If electrons scatter off stellar photons, the break is not reproduced  Assume that the break is due to γγ absorption  Typical energy of absorbed photons: tens of GeV 2 Eabs ~ (Ee,rest mass ) E ~ 30 GeV If 10 times of this Yamaguchi & Takahara, 2010, ApJ, 717, 85 3G Eabs ~ 3 GeV Therefore,  We assume that electrons scatter off 100 eV photons 0.1G Requirement for 100eV source  Optical depth τ > 1 R100eV  108 cm  No influence on Suzaku data R100eV  108 cm γ-ray injection site Electron injection 8 10 cm  Energy of e± < 1TeV  near 100 eV source 100eV source  Magnetic field: a parameter  we calculate cascade with 100eV photons, and with stellar photons far from it i  30 , 1 GeV  Ee, inj  50 TeV(index: 2.5)  B = 100 G    B = 300 G  GeV break is reproduced X-ray spectral index matches when B=100G X-ray flux matches when B=300G No orbital variation in X-ray and GeV band Strong magnetic field  Uph (100 eV) > Uph(stellar photon) → IC cooling time shorter → the number of e± smaller → strong B is required to fit with obs. Superior conjunction No variation in GeV & X-ray band  e± scatter off photons near CS O star CS → direction to CS independent of phase Inferior conjunction → No modulation in GeV band  No change in the number of electrons → No modulation in X-ray band O star CS For LS 5039, the observed break energy in GeV band is 3 GeV, different from expected one  So we introduce 100eV photon source  spectral break is reproduced  X-ray flux is reproduced when B = 300 G  X-ray & GeV have no variation (by isotropy of 100eV source)  This is a possible model! prospect  With 100eV source, we introduce orbital variation of injection (as in Owocki et al. 2010, proceeding)  Without 100eV source, we regard GeV cutoff as high energy cutoff of injected e± 