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The Molecular Gas in QSOs

The Molecular Gas in QSOs. XiaoYang, Xia Center for Astrophysics Tianjin Normal University Collaborators Y. Gao, Hao, Flaquer, Mao, Leon and Omont. Outline. Motivations The CO observations for IR QSOs by IRAM Comparing with ULIRGs

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The Molecular Gas in QSOs

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  1. The Molecular Gas in QSOs XiaoYang, Xia Center for Astrophysics Tianjin Normal University Collaborators Y. Gao, Hao, Flaquer, Mao, Leon and Omont

  2. Outline • Motivations • The CO observations for IR QSOs by IRAM • Comparing with ULIRGs • Comparing with CO detected local PG+HE QSOs and high-z QSOs

  3. The correlation between Black hole mass and spheroid • Is it valid for high-z galaxies? • When and how this correlation built up? Coppin et all. 2008

  4. IR QSOs are in last stage of merger And with Lir>10^12 Lsun

  5. Mrk231

  6. To answer following questions • Is far-infrared emission of IR QSOs mainly from starburst, instead of central AGN? • Do IR QSOs have enough cold molecular gas reservior to sustain star formation? • Are IR QSOs in the stage that Msph/Mbh relation is building? • Which high-z QSOs are scale-up of IR QSO?

  7. IR QSO and ULIRGs samples IR QSOs Selected from Hao et al. 2005 19 with z<0.18 Observed at 2008 fall (50 hours) by IRAM 30m and detected 15 Plus 6 archive, IR CO detected IR QSOs are21 ULIRGs 36Solomon et al.1997

  8. 15/19 IR QSOs detected by IRAM 30m

  9. Same Gas contet 10^9-10^10 Msun • Same SFE (Lfir/Lco’) • Similar FWHM • Time scale For SF can last several10^7 yrs enough cold gas to sustain star burst

  10. Sample of low-z classical QSOs and high-z submm luminous QSOs (co-detected) PG & HE QSOs 24 (Hamburg/ESO survey) Scoville et al. (2003), Evans et al. 2001, 2006 (z<0.1) Bertram et al. 2008 ( z<0.06) high-z QSOs 29collected by Wang et al. 2010 (z=2, 4, 6)

  11. Tight correlation • Non-linear • No gap for Low and high-z QSOs Slop=1.44

  12. LPAH vs. Lco’ Slop=1.25

  13. Star formation gives significant contribution to far-infrared emission for all QSOs

  14. Star formation efficency Lfir/Lco’ ∝LHCN/Lco’(gao&Slomon, 2004) dence gas fraction

  15. Dence gas fraction • IR QSO Mrk231 and I Zw I 1kpc gas disk/ring • High-z QSOs (APM 08279+5255, Cloverleaf, J1148+5251) observed by high resolution VLA with gas disk less than 1kpc (Riechers et al. 2009, Walter et al. 2009 and Bradford et al. 2009) However, the cold molecular gas contents are one order of magnitude higher for high-z QSOs, so the dence gas fraction of high-z QSOs must be higher

  16. The correlation between Lbol and Lco’ may implies that both QSO activity and star formation are dependent on same cold gas reservior

  17. BH accretion efficiency (Lbol/Lco’)for classical QSOs and the brightest high-z QSOs is much higher than Those of QSOs in transition stage

  18. Histogram of Lfir/Lbol (SFR/Mdot)

  19. IR QSO PG QSOs high-z QSOs Mdot/SFR 2.7x10^-3 0.8-1.6x10^-2 Local Mbh/Msph=1.4x10^-3 (Raring & Rix, 2004) BH and spheriod coevally evolve only for IR QSOs and some relatively faint high-z QSOs

  20. After transition stage, the accretion of cold molecular gas to central SMBH is more efficient when the star formation on central kpc scale has not dominated in the energy output This is consistant with simulation result by Hopkins (2010) that AGN peak is several times 10^7 years delay

  21. the estimation of time scale of co-evolution • by Mgas/SFR several times 10^107 years • by spatial density

  22. the estimation of time scale of co-evolution by spatial density • fraction of IR QSOs in ULIRGs is about 6% (zheng et al. 2002, Hao et al. 2005) • the QSO fraction (broad emission line AGN) in SMGs is about 4% (Chapman et al. 2005) • The fraction of CO detected submm luminous QSOs is about 30% (Chapman, 2005), but outlier of QSOs is only 10% (3/28), then high-z QSOs with low Mdot/SFR is 4% The time scale is few times 10^7 years

  23. In the transition stage of QSO (10^7 years), the local Mbh/Msph relation could not be built up

  24. Summary • The cold molecular gas content of IR QSOs is as the same as those of ULIRGs (a few times of 10^9- 10^10Msun), there is sufficient fule to sunstain massive star star formation in several 10^7 years • There is correlation between Lbol and cold molecular gas content for all QSOs, implying the same cold gas reservoir for QSO and star formation. • Only few high-z relatively faint QSOs are like local IR QSOs with high SFR and high accretion rate, during which the spheriod and black hole co-evolve, but the local Mbh/Msphe relation could not be built up during this stage.

  25. Thank you

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