Characterizing the Far-infrared Properties of Distant X-ray Detected AGNs

1. Characterizing the Far-infrared Properties of Distant X-ray Detected AGNs Author: J.R.Mullaney et al. Reporter: SaiyuHou (侯赛玉)

2. Outline • Background • Data • Results • Discussion • Summary

3. Outline • Background • Data • Results • Discussion • Summary

4. Background • X-ray • Infrared (MIR:5-30 µm FIR:30-300µm) • AGNs & Star burst systems

5. Outline • Background • Data • Results • Discussion • Summary

6. Data • X-ray: CDF-S • Spitzer-IRS spectra • Comparison samples • IRAS data for the Swift-BAT sample • NGC 1068& NGC 6240 • distance QSO

7. Data: Chandra Data • 1 Ms CDF-S • Classification (AGNs /SF galaxies) • Absorption corrected Lx and NH, Redshift • Absorption and selection bias • Full sample, Restricted sample

10. Data: Spitzer Data • 24 µm and 70 µm sources • Matching with X-ray sources • Stacking (most X-ray sources not detected at 70 µm)

11. Data: Comparison Samples • Swift-BAT Sample • Separating the sample into AGN or SB dominating • S70/S24 ratio (out to z~1.5) • 70 µm flux density can predict the LIR

14. Data: Comparison Sample • NGC 1068: heavily obscured typeII AGN with a hidden broad line region • NGC 6240: SB- dominated at IR, heavily obscured faint X-ray AGN • QSO: luminous and unobscured type I AGNs

16. Outline • Background • Data • Results • Discussion • Summary

17. Results • S70/S24 ratio: distinguish AGN or SB dominating IR SEDs • Calculating IR lum of 70 µm-detected AGNs

18. Results • no difference in the ratio between BLAGNs and non-BLAGNs, X-ray abs and unabs AGNs • the material that absorbs photons at X-ray and optical wavelengths is optically thin to rest frame MIR–FIR radiation

21. Results • 70 µm detected CDF-S X-ray AGNs are typically more IR luminous than their counterparts in the BAT/IRAS sample local AGNs • 70 µm detected SBs have higher LIR/LX ratios than most of the 70 µm detected AGNs

24. Results • more X-ray luminous AGNs may have, on average, more AGN-dominated SEDs • LX = 1042-43 erg/s AGNs’ LIR/LX evolves strongly with redshift • LX = 1043-44 erg/s AGNs’ LIR/LX increases less conclusive • Searching for intrinsically bright LX = 1043-44 erg/s AGNs, or Compton-thick AGNs

27. Outline • Background • Data • Results • Discussion • Summary

28. What is driving the increase in LIR • Increasing star formation • Large AGN dust covering factors: intrinsic emission reprocessed by dust

29. Contribution to cosmic IR background • AGNs’ contribution to the 70 µm background is very small • Bright AGNs are rare in CDF-S

30. Expected form Herschel

33. Outline • Background • Data • Results • Discussion • Summary

34. Summary 1 • at both 24 µm and 70 µm • For LX= 1042-43erg/s AGNs LIR/LX ratio increase • the average LIR at z = 1 − 2 is significantly higher than those at z = 0.5 − 1 and z ≈ 0 • For LX= 1043-44erg/s AGNs, not • A method to identify Compton-thick AGNs

35. Summary 2 • The process driving the increase • Increased star-formation • Increased AGN dust covering factors

36. Summary 3 • more X-ray luminous CDF-S AGNs have more AGN-dominated IR SEDs

37. Summary 4 • X-ray detected AGNs in the CDF-S contribute only a little of the 70 µm background

38. Summary 5 • Herschel Space Observatory • the FIR diagnostics able to discriminate between AGNs with SB- or AGN-dominated IR SEDs

39. Thanks