1 / 20

Constraining Spins of SMBHs from TeV Variability

Constraining Spins of SMBHs from TeV Variability. Yan-Rong Li (IHEP) Ye-Fei Yuan (USTC), Jian-Min Wang (IHEP) Jian-Cheng Wang (YNAO), Shu Zhang (IHEP) 2009.4.28

goforthj
Download Presentation

Constraining Spins of SMBHs from TeV Variability

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. Constraining Spins of SMBHs from TeV Variability Yan-Rong Li (IHEP) Ye-Fei Yuan (USTC), Jian-Min Wang (IHEP) Jian-Cheng Wang (YNAO), Shu Zhang (IHEP) 2009.4.28 Refs: Wang, J. -M. , Li, Y. -R. et al. 2008, ApJ, 676, L109 Li, Y.-R. et al. 2009, ApJ in press

  2. Outline • Introduction: TeV variability in M87 • Constraints of Pair Production • ADAFs/RIAFs in M87 • Optical Depth to ~TeV photons • Summary

  3. I. Introduction M87 • A radio galaxy at 16Mpc with Mbh=3.0×109M⊙(Macchetto et al 1996, Harms et al. 1994) • Inclination of jet: 30° (Bicknell et al. 1996) • Variability time scale: Aharonian et al 2006, Science HESS

  4. I. Introduction • The characteristic size, Size:20Rg • The possible source of the TeV-rays is the nucleus of M87 itself (Aharonian et al. 2006). • emission mechanism: Levinson 2000, Neronov & Aharonian 2007, Rieger & Aharonian 2008 • Question: how do TeV photons escape?

  5. II Constraints of Pair Production Pair production processes

  6. II. Constraints of Pair Production • TeV photons are used as a tracer to probe the radiation fields around BHs

  7. II. Constraints of Pair Production • Radiation field: accretion rate and spin • orientation: 30° • BH mass: Mbh=3.0×109M⊙ • accretion rate? • spin? Only fitting SED is not enough! • Supplementing TeV constraints relax the degeneration of the spin and the accretion rate.

  8. III. ADAFs/RIAFs in M87 SED shows: ADAFs/RIAFs is working due to the absence of Big Blue Bump Radio: VLBI (0.1″), IR: Gemini (460″), Optical: HST (22″), X-ray: Chandra (500″) (see Di Matteo et al. 2003, Wang et al. 2008)

  9. III. ADAFs/RIAFs in M87 • Fully GR ADAFs/RIAFs model (Manmoto 2000) • Radiation Processes Synchrotron Inverse Compton Scattering Bremsstrahlung

  10. III. ADAFs/RIAFs in M87 • Free Parameters • : spin • : accretion rate • : viscoisty • : magnetic • : viscous dissipation that heats electrons • : the observation angle. • have typical value from physical model. • Spectral fit • To reduce the freedom, fix , adjust .

  11. III. ADAFs/RIAFs in M87 (data see Di Matteo et al. 2003, Wang et al. 2008)

  12. III. ADAFs/RIAFs in M87 (data see Di Matteo et al. 2003, Wang et al. 2008 add HST observation from Sparks et al. 1996, Maoz et al. 2005 )

  13. IV. Optical Depth to TeV Photons Ray tracing

  14. IV. Optical Depth to TeV Photons

  15. IV. Optical Depth to TeV Photons

  16. IV. Optical Depth to TeV Photons

  17. IV. Optical Depth to TeV Photons To avoid being optically thick to 10TeV photons, the spin of SMBH in M87 should be a>0.8

  18. V. Summary • We use fully GR solutions of ADAFs/RIAFs. • We use the GR time-space to calculate the optical depth. • The SMBH in M87 is spinning fast.

  19. V. Summary • The TeV variability can be used to probe the innermost regions around the central black hole and allows us to disentangle the spin from other parameters in modeling the continuum spectrum. • Future H.E.S.S. (phase II) observations may reveal the TeV variability of M87-like sources.

More Related