IR QSOs at low and high redshift

1. IR QSOs at low and high redshift X.Y.Xia Tianjin Normal University, China Collaborators: C.N.Hao, S.Mao, H.Wu & Z.G.Deng

2. Motivation • The tight correlation between Mbh and σof host galaxy Kommendy&Gebhardt 2001, Merritt & Ferrarese 2001 • The relation of SFR/Mdot vs. Mbh Heckman & Kauffmann 2004 • IR QSO is ideal laboratory for study such process-coeval of starburst and BH growing

3. Heckman & Kauffman, 2004, based on 23000 SDSS narrow emission line AGN

4. Motivation • The tight correlation between Mbh and σof host galaxy Kommendy&Gebhardt 2001, Merritt & Ferrarese 2001 • The relation of SFR/Mdot vs. Mbh Heckman & Kauffmann 2004 • IR QSO is ideal laboratory for study such process--coeval of starburst and BH growing

5. Transition stage from merger to ellipticals

9. IR QSOs are in transitionary stage • Strong FeII emitters • High Eddington ratio • Steep x-ray slop at one extreme end of Eigenvecgtor 1 and they are young QSOs • Starburst

10. Key point • The starburst and central AGN give main contributions at different waveband • By comparing optical and IR QSOs sample, It is possible to separate the contributions • Determining SFR and Mdot

11. IR QSOs at Low redshift • IR QSO sample Zheng et al. (2002) (2)The optically-selected QSO sample PG QSOs , BG92 (1992), Haas et al. (2003) • NLS1 sample Wang & Lu (2001)

12. Sample Selection • QDOTIRAS galaxy sample(Lawrence et al. 1999) • 1 JyULIRGs sample(Kim & Sanders 1998) • IRAS-ROSATcross-identification sample(Moran et al. 1996) • A sample of 31 IR QSOs (z<0.35)，takes a fraction • of about 25% in local universe. Based on the sample, statistical results should be representative.

13. Estimation of physical parameters at low z • (1) Black hole mass: • (Kaspi et al. 2000) • (2) Bolometric luminosity: (Kaspi et al. 2000) • (3) Accretion rate: (Peterson 1997) • Star formation rate: • (Kennicutt 1998; Lawrence et al. 1989; Cardiel et al. 2003)

20. Heckman & Kauffman, 2004, based on 23000 SDSS narrow emission line galaxies

21. High-z QSOs Current available data at radio, UV and X-ray show No any difference between low-z and high-z QSOs

22. High-z QSOs The sample • Optically selected QSOs at redshift about 4 with 1.2mm observation, Omont et al. (2001) • Optically selected QSOs at redshift about 4 with 1.2mm observation, Carilli et al. (2001) • Optically selected QSOs at redshift about 2 with 1.2mm observation, Omont et al. (2003)

23. T=41K, ß=1.95

25. Parameters estimates at high z SFR:Monochromatic luminosity at 60m the monochromatic luminosity at 60m from the flux density at 1.2mm by assuming the rest-frame FIR SED can be described by a greybody spectrum with the dust temperature of 41K and the dust emissivity of 1.95 Priddey & McMahon (2001). Mdot: Bolometric luminosity Vestergaard (2004 )

29. QSOs Narrow emission Line AGN

30. Summary • IR QSOs (at both low and high redshift) are ideal laboratory for study the starburst and black hole growing process extending sample • The relation of SFR/Mdot with Mbh may indicate the strong outflow from central AGN for bright QSOs

31. Thank You

32. Conclusions (1) The optical emission of both infrared and optically selected QSOs and NLS1s is mainly from the central AGN, the infrared excess, especially far-infrared excess of IR QSOs should come from starbursts. (2) Star formation rate and accretion rate onto the central BH in IR QSOs at low redshift follow Mbulge- MBH relation, i.e., the ratio of the star formation rate and the accretion rate is about several hundred for IR QSOs, but decreases with the central black hole mass. This shows that the tight correlation between the stellar mass and the central black hole mass is preserved in massive starbursts during violent mergers. (3) Similar to IR QSOs at low redshift, the optically selected QSOs detected at mm band at high redshift have far-infrared excess compared to optical AGNs at low redshift, which should be due to the contribution of starbursts heating the dust. (4) The ratio of star formation rate to accretion rate for QSOs at high redshift is typically smaller than that for IR QSOs at low redshift, which hints the relatively faster growth of black holes at early epochs.

33. (4) IR QSOs are accreting and forming stars at the same time. Therefore, it is an ideal laboratory for us to explore the connection between black hole accretion and star formation. We find that the star formation rate and accretion rate in IR QSOs follow the relation: Notice that the derivation of SFR is from the monochromatic luminosity at 60m due to starbursts, i.e., the contribution from AGN to L(60 m) has been subtracted by assuming IR QSOs follow the same regression relation as optical AGNs (the solid line in Fig. 2c).

36. Log (Lx/LFIR) vs. Hß blueshift

37. Discussion Hß blueshift Outflows Hß blueshift vs. FeII4570/Hß Outflows FeII emission High fraction of strong Fe II emitters

40. Estimation of physical parameters at low z • (1) Black hole mass: • (Kaspi et al. 2000) • (2) Bolometric luminosity: (Kaspi et al. 2000) • (3) Accretion rate: (Peterson 1997) • Star formation rate: • (Kennicutt 1998; Lawrence et al. 1989; Cardiel et al. 2003)

44. Heckman & Kauffman, 2004, based on 23000 SDSS narrow emission line galaxies