1 / 30

The evolution of SMBH from Hard X-ray surveys

The evolution of SMBH from Hard X-ray surveys . The XRB as a tracer of SMBH mass density Hard X-ray surveys: observational results Near-IR observations of hard X-ray sources Evidences of merging Conclusions and perspectives. Andrea Comastri (INAF – Osservatorio di Bologna – Italy).

oshin
Download Presentation

The evolution of SMBH from Hard X-ray surveys

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. The evolution of SMBH from Hard X-ray surveys • The XRB as a tracer of SMBH mass density • Hard X-ray surveys: observational results • Near-IR observations of hard X-ray sources • Evidences of merging • Conclusions and perspectives Andrea Comastri (INAF – Osservatorio di Bologna – Italy)

  2. Hard X-ray Surveys • Most direct probe of the super-massive black hole (SMBH) accretion activity recorded in the XRB spectral energy density • Chandra and XMM surveys: SMBH census is almost complete (integral)  obscured AGN make the bulk of the XRB • The light-up and evolution of obscured accreting SMBH is still largely unknown (differential)  XLF evolution of obscured AGN

  3. The deepest X-ray sky Chandra Surveys, 1 Ms exposures CDFS (Giacconi et al. 2002) HDFN (Brandt et al. 2001)

  4. The origin of the cosmic XRB A truly diffuse component not exceeding 10% of the observed flux (warm IGM, missing baryons …)may still be present in the soft (below 2 keV) X-ray band  the hard XRB (2-100 keV) is due to single sources (X-ray surveys, CMB argument) OBSCURED AGN

  5. SMBH mass density from XRB (Fabian & Iwasawa 1999)

  6. Where all the SMBH have gone ? N(L), N(z), efficiency, bolometric correction ?

  7. DEEP FIELDS: Redshift Distributions • CDFN, Barger et al. 2002 CDFS, Gilli 2003

  8. Cosmic Sheets Z=0.67 CDFS CDFN

  9. X-ray source clusteringYang et al. 2003 (astro-ph/0302137) • Hard X-ray sources more clustered than soft ones

  10. The same LSS is traced by both X-ray and near IR surveys Gilli et al. 2003 (astro-ph/0304177)

  11. Luminosity function: • Cowie et al. 2003 astro-ph/0301231 • Hasinger 2003 astro-ph/0302574

  12. Space density: • Cowie et al. 2003: rho_BH ~ 2x105 Hasinger 2003

  13. Deep Chandra surveys: limits • Small solid angle  lack of high z high L objects • Soft X-ray response  biased against highly obscured objects • Limited by faint optical counterparts and thus incomplete at high-z

  14. The Hellas2XMM survey • Wide and shallow: 3 deg2 (15 XMM public fields) ~30 sources/field, Fx>10-14  Bulk of the XRB • Rare and peculiar sources, avoid cosmic variance • Relatively “easy” multi-wavelength follow-up (ESO-VLT,3.6m, ATCA, VLA, TNG & Chandra)

  15. X/O -------- fX/fopt > 10 Likely to be highly obscured Undetected in the R-band at R=24-25 (shallow), even R>27-28 (deep) Constant fraction over a large range of fluxes Shallow surveys pick-up brightest sources  optical identification is possible

  16. Redshift from X-ray linesin the CDFN - R ~ 24 z= 1.15+-0.05

  17. 317 sources (Hellas2XMM + Lockman + CDFN + SSA13 -15 < logFx < -13.3 , 70% identified) Fiore et al. 2003

  18. Redshift distribution (Opt +stat. ids)

  19. The evolution of number and luminosity densities (Fiore et al. 2003) rho_BH ~ 4-6x105

  20. K-band observations of high X/0 Selection: • 11 sources • R > 24.5 • Flx(2-10) > 1.2 10-14 • VLT/ISAAC • 1 hour exp. in K • Seeing < 0.7 arcsec • Mag lim. ≈ 21

  21. ISAAC VLT K-band observations of high X/O 10/11 sources with a bright IR counterpart in the error box: ALL with R-K>5 ————————— Extremely red colors up to R-K~7 ! ————————— Extended morphologies Only two objects are compact (high z AGN ?) Elliptical, K=17.9, R-K=6.5 Pointlike, K=17.7, R-K>6.8 Cluster CD ?, K=18.7, R-K=6.0 Disky, K=18.4, R-K=5.8 (Mignoli et al, in prep.)

  22. High quality imaging • Surface brightness and effective radius BH mass estimate via FP and M(BH) vs. sigma relation NEED z Red=de Vaucouleurs Blue=exponential

  23. The X/O ratio is correlated with the R-K color:hope to get spectroscopic redshifts in the infrared

  24. Evidences of interacting SMBH

  25. Near IR imaging of hard X-ray sources:X-ray bright optically normal galaxies

  26. Concluding Remarks • The XRB appears to be dominated by low-z low-L objects • The SMBH mass density is almost equally accounted for by unobscured and obscured AGN (lower mass on average) • Obscured AGN are hosted by a wide variety of galaxy types • Redshifts for optically faint (high X/O) obscured sources urgently needed

  27. Broad Iron Lines at high z ?

  28. Comastri, Civano & Brusa (in prep.)

More Related