1 / 9

ガンマ線連星 LS 5039 における GeV 放射モデル

ガンマ線連星 LS 5039 における GeV 放射モデル. (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」. outline. Gamma-ray binary, LS5039 GeV break problem Model with a soft X-ray source Summary. Gamma-ray binaries.

zephania-branch
Download Presentation

ガンマ線連星 LS 5039 における GeV 放射モデル

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ガンマ線連星LS5039におけるGeV放射モデル • (Yamaguchi & Takahara2012, 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. outline • Gamma-ray binary, LS5039 • GeV break problem • Model with a soft X-ray source • Summary

  3. Gamma-ray binaries • Gamma-rays vary with orbital period • Gamma-rays are detected as flares • Candidate: AGL J2241+4454 (HD 215227(Be))

  4. Observations of LS 5039 F. Aharonian, et al., 2006, A&A, 460, 743 superior inferior 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 ・TeV& GeVanticorrelate ・TeV& X correlate ・spectral break at ~1 GeV Orbital phase Light curves

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

  6. Model with 100eV photons Requirement for 100eV source • 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 γ-ray injection site Electron injection 100eV source

  7. Results • 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. Discussion Strong magnetic field • Uph (100 eV) > Uph(stellarphoton) → 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 offphotonsnear 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 O star CS Inferior conjunction O star CS

  9. Summary • 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

More Related