IR QSOs at low and IR QSOs at low and high redshift high redshift

X.Y.XiaX.Y.XiaTianjin Normal University, ChinaTianjin Normal University, China

Collaborators: C.N.Hao, S.Mao, H.Wu & Z.G.DengCollaborators: C.N.Hao, S.Mao, H.Wu & Z.G.Deng

MotivationMotivation

• The tight correlation between Mbh The tight correlation between Mbh and and σσof host galaxyof host galaxy

Kommendy&Gebhardt 2001, Merritt & Ferrarese Kommendy&Gebhardt 2001, Merritt & Ferrarese 20012001

• The relation of SFR/Mdot vs. MbhThe relation of SFR/Mdot vs. Mbh Heckman & Kauffmann 2004Heckman & Kauffmann 2004

• IR QSO is ideal laboratory for study IR QSO is ideal laboratory for study such process-coeval of starburst and such process-coeval of starburst and BH growingBH growing

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

MotivationMotivation

• The tight correlation between Mbh The tight correlation between Mbh and and σσof host galaxyof host galaxy

Kommendy&Gebhardt 2001, Merritt & Ferrarese Kommendy&Gebhardt 2001, Merritt & Ferrarese 20012001

• The relation of SFR/Mdot vs. MbhThe relation of SFR/Mdot vs. Mbh Heckman & Kauffmann 2004Heckman & Kauffmann 2004

• IR QSO is ideal laboratory for study IR QSO is ideal laboratory for study such process--coeval of starburst and such process--coeval of starburst and BH growingBH growing

Transition stage from merger to ellipticals

IR QSOs are in transitionary IR QSOs are in transitionary stagestage

• Strong FeII emittersStrong FeII emitters

• High Eddington ratioHigh Eddington ratio

• Steep x-ray slopSteep x-ray slop

at one extreme end of Eigenvecgtor 1 and at one extreme end of Eigenvecgtor 1 and they are young QSOsthey are young QSOs

• StarburstStarburst

Key pointKey point

• The starburst and central AGN give main The starburst and central AGN give main contributions at different wavebandcontributions at different waveband

• By comparing optical and IR QSOs sample,By comparing optical and IR QSOs sample,

It is possible to separate the contributionsIt is possible to separate the contributions

• Determining SFR and MdotDetermining SFR and Mdot

IR QSOs at Low redshiftIR QSOs at Low redshift

(1)(1) IR QSO sampleIR QSO sample

Zheng et al. (2002)Zheng et al. (2002)

(2)(2) The optically-selected QSO sampleThe optically-selected QSO sample

PG QSOs , BG92 (1992), Haas et al. (2003)PG QSOs , BG92 (1992), Haas et al. (2003)

(3)(3) NLS1 sampleNLS1 sample Wang & Lu (2001)Wang & Lu (2001)

Sample SelectionSample Selection

• QDOTQDOT IRAS galaxy sampleIRAS galaxy sample (Lawrence et al. (Lawrence et al. 1999)1999)

• 1 Jy1 Jy ULIRGs sampleULIRGs sample (Kim & Sanders 1998)(Kim & Sanders 1998)

• IRAS-ROSATIRAS-ROSAT cross-identification samplecross-identification sample (Moran et al. 1996)(Moran et al. 1996)

A sample ofA sample of 31 31 IR QSOs (IR QSOs (z<0.35z<0.35)) ，， takes a takes a

fraction fraction

of about of about 25% 25% in local universe. Based on the in local universe. Based on the sample, statistical results should be representativesample, statistical results should be representative..

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)

(4) Star formation rate:

(Kennicutt 1998; Lawrence et al. 1989; Cardiel et al. 2003)

G

VRM BLR

BH

2

)5100(9 ALLbol

2C

LM bol

sun

msun L

LyrMSFR

10

601

1052.6

29.0

118.588

yrM

M

yrM

SFR

sunsun

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

High-z QSOsHigh-z QSOs

Current available data at radio, UV Current available data at radio, UV and X-ray showand X-ray show

No any difference between No any difference between low-z and high-z QSOs low-z and high-z QSOs

The sampleThe sample

(1)(1)Optically selected QSOs at redshift about 4 Optically selected QSOs at redshift about 4 with 1.2mm observation, with 1.2mm observation, Omont et al. (2001)Omont et al. (2001)

(2)(2)Optically selected QSOs at redshift about 4 Optically selected QSOs at redshift about 4 with 1.2mm observation, with 1.2mm observation, Carilli et al. (2001)Carilli et al. (2001)

(3)(3)Optically selected QSOs at redshift about 2 Optically selected QSOs at redshift about 2 with 1.2mm observation, with 1.2mm observation, Omont et al. (2003)Omont et al. (2003)

High-z QSOsHigh-z QSOs

T=41K, ß=1.95

Parameters estimates at Parameters estimates at high zhigh zSFRSFR:: Monochromatic luminosity at 60Monochromatic luminosity at 60mm the monochromatic luminosity at 60the monochromatic luminosity at 60m from the m from the

flux density at 1.2mm by assuming the rest-flux density at 1.2mm by assuming the rest-frame FIR SED can be described by frame FIR SED can be described by

a greybody spectrum with the dust temperature a greybody spectrum with the dust temperature of 41K and the dust emissivity of 1.95 of 41K and the dust emissivity of 1.95

Priddey & McMahon (2001).Priddey & McMahon (2001).

MdotMdot:: Bolometric luminosity Bolometric luminosity Vestergaard Vestergaard (2004 )(2004 )

Bbol LL 74.9

QSOs

Narrow emissionLine AGN

SummarySummary

• IR QSOs (at both low and high IR QSOs (at both low and high redshift) are ideal laboratory for redshift) are ideal laboratory for study the starburst and black hole study the starburst and black hole growing processgrowing process

extending sampleextending sample• The relation of SFR/Mdot with Mbh The relation of SFR/Mdot with Mbh

may indicate the strong outflow from may indicate the strong outflow from central AGN for bright QSOscentral AGN for bright QSOs

ConclusionsConclusions

(1) The optical emission of both infrared and optically selected QSOs (1) The optical emission of both infrared and optically selected QSOs and NLS1s is mainly from the central AGN, the infrared excess, and NLS1s is mainly from the central AGN, the infrared excess, especially far-infrared excess of IR QSOs should come from especially far-infrared excess of IR QSOs should come from starbursts.starbursts.

(2) Star formation rate and accretion rate onto the central BH in IR (2) Star formation rate and accretion rate onto the central BH in IR QSOs at low redshift follow QSOs at low redshift follow MMbulgebulge- M- MBHBH relation, i.e., the ratio of the relation, i.e., the ratio of the star formation rate and the accretion rate is about several hundred star formation rate and the accretion rate is about several hundred for IR QSOs, but decreases with the central black hole mass. This for IR QSOs, but decreases with the central black hole mass. This shows that the tight correlation between the stellar mass and the shows that the tight correlation between the stellar mass and the central black hole mass is preserved in massive starbursts during central black hole mass is preserved in massive starbursts during violent mergers. violent mergers.

(3) Similar to IR QSOs at low redshift, the optically selected QSOs (3) Similar to IR QSOs at low redshift, the optically selected QSOs detected at mm band at high redshift have far-infrared excess detected at mm band at high redshift have far-infrared excess compared to optical AGNs at low redshift, which should be due to compared to optical AGNs at low redshift, which should be due to the contribution of starbursts heating the dust.the contribution of starbursts heating the dust.

(4) The ratio of star formation rate to accretion rate for QSOs at high (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, redshift is typically smaller than that for IR QSOs at low redshift, which hints the relatively faster growth of black holes at early which hints the relatively faster growth of black holes at early epochs.epochs.

(4) IR QSOs are accreting and forming stars at the same time. (4) IR QSOs are accreting and forming stars at the same time. Therefore, it is an ideal laboratory for us to explore the Therefore, it is an ideal laboratory for us to explore the connection between black hole accretion and star formation. connection between black hole accretion and star formation. We find that the star formation rate and accretion rate in IR We find that the star formation rate and accretion rate in IR QSOs follow the relation: QSOs follow the relation:

Notice that the derivation of SFR is from the monochromatic Notice that the derivation of SFR is from the monochromatic

luminosity at 60luminosity at 60m due to starbursts, i.e., the contribution m due to starbursts, i.e., the contribution from AGN to from AGN to LL(60 (60 m) has been subtracted by assuming IR m) has been subtracted by assuming IR QSOs follow the same regression relation as optical AGNs QSOs follow the same regression relation as optical AGNs (the solid line in Fig. 2c).(the solid line in Fig. 2c).

29.0

118.588

yrM

M

yrM

SFR

sunsun

Log (Lx/LFIR) vs. Hß blueshift

DiscussionDiscussion

Hß blueshift vs.

FeII4570/Hß

High fraction of strong Fe II

emitters

Outflows

FeII emission

Hß blueshift

Outflows

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)

(4) Star formation rate:

(Kennicutt 1998; Lawrence et al. 1989; Cardiel et al. 2003)

G

VRM BLR

BH

2

)5100(9 ALLbol

2C

LM bol

sun

msun L

LyrMSFR

10

601

1052.6

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