High-z (z > 3) QSOs studied with Subaru/HSC

Masa Imanishi (NAOJ)

Tohru Nagao (NAOJ)

Outline

1. Importance and current understanding of high-z QSOs (AGNs)

3. Low-luminosity QSOs at z = 3-6

2. QSOs at z > 7

(Subaru/HSC + UKIRT/WFCAM)

(Subaru/HSC)

(M.Imanishi)

(T.Nagao)

Why High-z QSOs(AGNs) ?

(1) Very bright

(2) Co-Evolution of SMBHs and Galaxies

SMBHs are ubiquitous in spheroid galaxies

M(gal)M

(BH

)

IGM properties (re-ionization)

DLA, LyA forest

MBH =106-9Msun

High-z QSO found by SDSS

z>7 QSO not detectablein the optical

z=6.42:Most distant

1um @z~7

Fan 2006

>1000 QSOs at z>3

Bright QSOs only !

Post SDSS QSO Survey

(2) Search for lower-Luminosity QSOs at z = 3-6

(1) Search for z > 7 QSOs

What next?

NIR data required

(UKIRT/WFCAM)

1. z>7 QSOs

Very deep Moderately deep

Z Y J H K

NIRoptical

filters

UKIRT/WFCAM/LAS

Northern: 1907.6 deg^2

Equatorial: 1907.6 deg^2

Y=20.5,J=20.0,H=18.8,K=18.4

z>7 QSOs:~10 expected

No deep z-band image:z>7 QSO candidates cannot be selected

z>7 QSO:z– NIR = very large

SDSS + >2 magneededJ - KJ - K

z’ -

J

z’ -

J

WFCAM team compromise Y-band

i ,Y: limiting mag differs only 2mag

Green： QSO

Red： BD

Y-J color difference (small)

Severe contamination

i z Y

J

i’ -

Y

Y - J

Proposal

>1000 deg 2(wide), z>23.5mag (deep) surveyPossible only with Subaru/HSC

The planned Subaru/HSC >1000 deg 2 survey be executed at (northern) WFCAM/LAS

RA widely distributed

RA

DE

C

Why Japan?

Japan can lead this area, if we do follow-up before HSC data become archival !

Deep, wide z-band survey only possible with HSC

Subaru/MOIRCS can

At z~7, z-ID requires 0.9-1.5um spectroscopy

Southern VISTA : Z<21.5 （ ?）

Issues to be solved

SDSS z or Z

SDSS z

Z-band

1 (um)0.8

Y dwarf

2. low-luminosity QSOs (z=3-6)

Croom et al. (2001)

２ｄＦz<2.3

faint bright

Fan et al. (2001) bright

SDSSz>3.6

QSO LF:

bright end only at z>3

QSO UV background:dominated by faint end

QSO (Mathews & Ferland 1989)

Starburst, Z=0.05 Zsolar

Starburst, Z=1.00 Zsolar

13.6eV24.6eV

54.4eV

(Leitherer et al. 1999)

UV Background from QSOs at z=3-6

QSO UV is hard

QSOs

Stars

HeII re-ionization

Effect on galaxy formation

Energy (Rydberg)

QSO Correlation Func.

Faint, numerous QSOs

Corr.Func. bias M(halo) QSO lifetime

Croom et al. (2005)

Redshift0 1 2

bia

s

z < 3

z > 3:unknown

Enoki et al. (2003)

108yr

107yrb e

ff

4

5

6

7

z3 3.5 4 4.5 5

4

5

6

7log MDH/Msun=12.5

12.0

11.5

3

bia

s

Redshift

Strategy

SDSS ~ too shallow…Deep Surveys (UDF, SDF) ~ too narrow…

Moderately Deep andModerately Wide QSO Surveys

Multi-band Selection

3000 Wavelength(A) 10000

Richards et al. (2001)g’ — r’ r’ — i’

r’ —

i’

i’ —

z’

Selection in Color-Color Diagram g’r’i’ 3.6 < z < 4.4 r’i’z’ 4.6 < z < 5.1

u g r i z

Survey Strategy

Multi-band HSC Survey g’ r’ i’ z’ (3mag deeper than SDSS)

g’r’i’z’

26.6mag (23.3)

26.2mag (23.1)

25.5mag (22.3)

24.4mag (20.8)

20min/band/FOV(5σ, 0.7”seeing, 2”φ)

100 QSOs ~ 140 sq.deg. ~ 100 FOV ~ 400 pointing ~ 2 weeks

HSC

Summary

2. Low-luminosity QSOs at z = 3-6

1. QSOs at z > 7

(Subaru/HSC + UKIRT/WFCAM)

(Subaru/HSC)

End

QSO Environment

QSO Activity Interaction

Results at z=0.2 　 (McLure & Dunlop 2001)

Borne et al. (2000)

Bright galaxy number excess around QSOs

excess QSOsBlank-field

Strategy

Trigger of QSO ActivityGrowth of SMBHs in QSOsRelation with Galaxy Evolution

Luminosity Function of QSOsCorrelation Function of QSOsEnvironments of QSOs

We need a QSO sample~ with wide luminosity range~ with enough number density

SDSS ~ too shallow…Deep Surveys (UDF, SDF) ~ too narrow…

Moderately Deepand

Moderately WideQSO Surveys

QSO Correlation Func. Croom et al. (2005)

Redshift

b eff

4

5

6

7

z3 3.5 4 4.5 5

4

5

6

7log MDH/Msun=12.5

12.0

11.5

tQ=3x108 yr

tQ=3x107 yr

Enoki et al. (2003)

～ Corr.Func. bias Mhalo

～ bias QSO Lifetime — mass-accretion timescale

Co-Evolution of SMBHs and Galaxies

Ferrarese & Meritt (2000)

MBH

[Msu

n]stellar velocity dispersion

Non-AGNs

Marconi & Hunt (2004)

log Mgal [Msun]

log

MBH

[Msu

n]

MBH/Mgal ～ 0.002

～ Evolutionary link between SMBHs and galaxies～ Every galaxies may once experienced an AGN phase

SDSS QSO Survey: Redshift Distribution

Richards et al. (2006)

Schneider et al. (2005)

46420 QSOsin SDSS DR3

0 1 2 3 4 5Redshift

u’-

dro

pout

g’-

dro

pout