Presentation is loading. Please wait.

Presentation is loading. Please wait.

(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」

Similar presentations


Presentation on theme: "(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」"— Presentation transcript:

1 (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」

2 I. Gamma-ray binary, LS5039 II. GeV break problem III. Model with a soft X-ray source IV. Summary

3 Gamma-rays vary with orbital period Gamma-rays are detected as flares  Candidate: AGL J (HD (Be)) Cyg X-15.6d3x10^12cmO + BH Cyg X-34.8hr5x10^11cmWR + ??(BH or NS) ObjectsPeriodScaleConsists of … LS d5x10^12cmO + ?? (BH or NS) LS I +61° 30326d10^13cmBe + ?? PSR B yr10^14cmBe + NS HESS J d10^14cmBe + ?? 1FGL J d10^13cmO + ??

4 A. A. Abdo, et al., 2009, ApJL, 706, 56 F. Aharonian, et al., 2006, A&A, 460, 743 T. Takahashi, et al., 2009, ApJ, 697, 592 Suzaku Fermi HESS ・ TeV & GeV anticorrelate ・ TeV & X correlate ・ spectral break at ~1 GeV Fermi Suzaku Photon energy (eV) Phase-averaged spectra Orbital phase Light curves MS superiorinferior HESS SUPC INFC SUPC

5  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  We assume that electrons scatter off 100 eV photons 0.1G 3G Yamaguchi & Takahara, 2010, ApJ, 717, 85 If 10 times of this Therefore,

6  Optical depth τ > 1  No influence on Suzaku data  Energy of e± < 1TeV  near 100 eV source  Magnetic field: a parameter  we calculate cascade with 100eV photons, and with stellar photons far from it 100eV source Requirement for 100eV source Electron injection injection site γ-ray

7  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 B = 100 G B = 300 G

8 Strong magnetic field  U ph (100 eV) > U ph (stellar photon) → IC cooling time shorter → the number of e± smaller → strong B is required to fit with obs. No variation in GeV & X-ray band  e± scatter off photons near CS → direction to CS independent of phase → No modulation in GeV band  No change in the number of electrons → No modulation in X-ray band Superior conjunction Inferior conjunction CS O star CS O star

9  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!  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± prospect


Download ppt "(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」"

Similar presentations


Ads by Google