Joint formation and evolution of SMBHs and their host galaxies:

Joint formation and evolution of SMBHs and their host galaxies:How do the Quasar-Spheroid correlations

change with the Cosmic Time?

A. Treves Università dell’Insubria, Como, ItalyR. Falomo INAF, Osservatorio Astronomico di Padova, ItalyR. Decarli Università dell’Insubria, Como, ItalyJ. Kotilainen Tuorla Observatory, Piikkio, FinlandM. Uslenghi INAF-IASF, Milano, Italy

Marzia Labita

Como, 31/10/2007 QSOs and their host galaxies 2

SMBHs and host galaxies Most (if not all) nearby (early type) galaxies host a

supermassive black hole (SMBH) at their centers- proper motion of stars (Milky Way)- rotation curves of gas clouds – MASER (22 objects)

The host galaxies of low redshift quasars contain a massive spheroidal component(observative results: see Dunlop et al. 2003, Pagani et al. 2003…)

Elliptical galaxies ↔ SMBHs


Joint formation of SMBHs and massive spheroids According to the hierarchical merging scenario, massive

spheroids should be the products of successive merging events

At low redshift, the central BH mass is strongly correlated to the properties of the host galaxy bulge (of both active and inactive galaxies)…OUTSIDE THE SPHERE OF INFLUENCE!

Formation of Formation and fuellingElliptical galaxies of their active nuclei


Quasar: Nuclear luminosity Radio power (RLQ – RQQ) Spectral shape

BH mass determination and evolution

Host Galaxy: Bulge luminosity (Stellar velocity dispersion, morphology, size)

Host galaxy luminosity (mass) evolution

Quasar – Host Galaxy connection: Study the BH – host mass correlation at low z and trace its

cosmological evolution close and beyond the peak of the quasar activity









The NIR to UV continuum of radio loud (RL) vs. radio quiet (RQ) quasarsM. Labita, A. Treves, R. Falomo, 2007, MNRAS, in press (astro-ph/0710.5035)Understanding the nuclear engine of quasars:

Characterization of the Spectral Energy Distribution (SED) Distinction between RLQs and RQQs in the Unified Models

of AGN(relativistic jet, BH spin?)

…compare and contrast the SEDs of RLQs and RQQs


First step: QSO sample selectionRequirements: Sample as large as possible Minimally biassed against the radio properties and the

nuclear color of the QSOs Observations in multiple bands (from NIR to UV) to

construct the SED Radio detection (RLQs vs. RQQs) Negligible host galaxy component

SDSS quasar catalogue (u, g, r, i, z) 2MASS detection (J, H, K) FIRST observation area (20 cm flux)


Distinction between RLQs and RQQs 91% of the objects are below the FIRST limit

RLQ if radio to optical flux ratio >10; RQQ otherwise We choose g<18.9, so that we can discriminate

between RLQs and RQQs

Host galaxy contribution Host luminosity estimate based on radio

power and redshiftWe require that host to nuclear flux ratio <0.2


887 QSOs (774 RQQs and 113 RLQs)

The final sample

redshift R band absolute magnitude


SED construction For each object, 8 datapoints log ν – log (νLv)

from the u, g, r, i, z, J, H, K observations Construction of the restframe SEDs of single

objects Normalization of the RLQs and RQQs

subsamples at 1014.8 Hz Construction of the average spectral energy

distributions


Average SEDs of RLQs and RQQs

RLQs are more luminous and redder than RQQs Huge dispersion of the spectral indices

POWER LAW FIT

RLQs

RQQs

ALL

log(v) Hz

log(

vLv)

erg/

s

log(

vLv)

rela

tive

log(v) Hz


Color difference between RLQs & RQQs

RLQs are redder than RQQs in the NIR to UV region with Δα = 0.2

P(KS)>99% Redshift independence Luminosity independence

(L – z matched samples)Spectral index

RLQsRQQs


SED shape: a possible bias

Request of 2MASS observation: only redder objects at high z Both the SEDs result softer for high z objects (i.e. at high frequencies) Let’s use 2MASS data only at low z!


Interpretation of the color difference Is there an enhanced dust extinction in

RLQs?

Difference of the thermal components?Big blue bump: superposition of black body emission from an accretion discColor difference ↔ Temperature difference

Is there a real temperature difference? Is the color difference related to spinning?

Difference of the non-thermal components?Is there synchrotron contamination from the relativistic jets in RLQs?


1. Is there an enhanced dust extinction in RLQs? ΔAV=0.16mag

would explain the difference

Why RLQs are more extinted?

1. Different inclinations?2. Dust production

related to radio emission?


2. Is there a real temperature difference? Tdisk÷MBH

-1/4

BHs of RLQs are supposedly more massive RQQs are expected to be hotter (and bluer) 3. Is the color difference related to spinning?

Radio emission is usually ascribed to faster spinning Spinning BHs (RLQs) have a shorter last stable orbit

radius and then a hotter disk → NO!


4. Is there synchrotron contamination from the relativistic jets in RLQs? In pole-on radio sources there is a significant

chance of synchrotron contamination from the relativistic jets

Radio selected samples suffer from a bias towards pole-on radio sources (relativistic beaming) but in our sample does not!

→The color difference between RLQs and RQQs is probably due to a real temperature difference of the accretion disks.NEXT STEP: quantify this effect!









First step: BH mass determinations at low zDynamical BH mass determinations:

VIRIAL THEOREM

Local Universe:

stars orbiting around the SMBH → only inactive galaxies Higher redshift:

gas regions emitting the broad lines – BLR → Type I AGN!

v = f ∙ line-width (Doppler Effect) UV? Optical? f = ?

R ÷ λ Lλα (from reverberation mapping) FWHM? σ-line?


Hβ broad emission of low-redshift quasars: Virial mass determination and the geometrical factor(Decarli R., Labita M., Treves A., Falomo R., 2007, submitted to MNRAS)AIM Solid base at low z to study nuclear-host

connection beyond the peak of the nuclear activity(see also Labita et al. 2006, MNRAS, 373, 551)

Are BH mass determinations from Hβ and from CIV consistent? Which is the better estimator? FWHM or σ-line?

SOLID RECEIPT FOR BH MASS DETERMINATION HINTS ON THE BLR GEOMETRY

Do the known correlations between the properties of QSOs and their host galaxies hold up to z~0.5?


The Sample Quasars, z<0.7, reliable host galaxy luminosity

determination, elliptical galaxyAbout 40 quasars at <z>~0.3 of which:

25ASIAGO

dedicated observations

29

HST archive spectra

12SDSS catalogue spectra

92

0

9

UV

optical


Data reduction, measurements and analysis Standard IRAF procedure

Subtraction of the FeII contamination (zero-order correction)

Monochromatic luminosity measurement (power-law fit) Line-width measurements:

Narrow component subtraction 2-gaussian fit of the broad

component FWHM and σ-line measurements:

σ-line is strongly dependent on the line wings…


CIV vs. Hβ: line shapes and line-widths

Hβ profile is more “gaussian” (isotropic case) than CIV R(Hβ)~1.5 R(CIV) but FWHM(Hβ)>FWHM(CIV) The geometries of the Hβ and CIV regions are intrinsically different


BH mass – host luminosity correlation

CIV mass estimates are well correlated with MR

Hβ mass estimates are barely correlated with MR

CIV line-width is a better velocity estimator than Hβ

We can constrain f by matching the mass estimates via the BH mass – host luminosity correlation

NO redshift dependence of this correlation


BH mass – host luminosity correlation

CIV mass estimates are well correlated with MR

Hβ mass estimates are barely correlated with MR

CIV line-width is a better velocity estimator than Hβ

We can constrain f by matching the mass estimates via the BH mass – host luminosity correlation

NO redshift dependence of this correlation


Hints on the BLR geometry Isotropic model

f=√3/2: ruled out Thin disc model

f(θmin, θmax): ok for CIV clouds

For Hβ clouds? Hβ shape R vs. FWHM Expected angles

Isotropic component + disc component

Thick disc model


ESO 3.6m+EFOSC2

The next step: QSOs at higher zSpectroscopical campaigns (ESO, TNG, NOT…) are going on to collect the spectra of QSOs with a reliable bulge magnitude estimate

In the meantime…







cosmological evolution close and beyond the peak of the quasar activity PRELIMINARY!


z~0.3z~1.5

z~2.5

BH – bulge mass correlation: evolution with z Γ=MBH/Mbulge

redshiftMR

log

MB

H

log

Γ

xx x


z~0.3z~1.5

z~2.5

BH – bulge mass correlation: evolution with z Γ=MBH/Mbulge

redshiftMR

log

MB

H

log

Γ

xx x


z~0.3z~1.5

z~2.5

BH – bulge mass correlation: evolution with z

redshiftMR

log

MB

H

log

Γ

x

Γ=MBH/Mbulge

Γ grows with z ?

x x








PRELIMINARY!



x

x



x

x



x

x

?

Hint: at z~2.5 (peak of the nuclear activity), well formed BHs are hosted by not completely formed galaxies


Summary and conclusions (I)

The NIR to UV continuum of RLQs vs. RQQs

For a sample of ~1000 objects with SDSS – 2MASS observations:

Average SED construction RLQs are more luminous than RQQs RLQs are redder than RQQs and this is independent on

redshift or luminosity RQQs seem to be hotter due to smaller BH masses (???)

FUTURE: Try to understand better why RLQs are redder than RQQs


Summary and conclusions (II)Joint formation and evolution of galaxies and SMBHs

LOW REDSHIFT Receipt for BH mass determination Known correlations between BH – host mass hold up to z~0.5

Labita M., Falomo R., Treves A., Uslenghi M., 2006, MNRAS, 373, 551Decarli R., Labita M., Treves A., Falomo R., 2007, submitted to MNRAS

HIGH REDSHIFT Host luminosity (mass?) SEEMS to increases with Cosmic Time (???)

Kotilainen J., Falomo R., Labita M, Treves A., Uslenghi M., 2007, ApJ, 660, 1039

Γ SEEMS to decrease with Cosmic Time (???) Hint: at z~2.5 (peak of the nuclear activity), well formed BHs are hosted

by not completely formed galaxies (???)

FUTURE: What will the new observations at higher redshift tell us?

Documents

Joint formation and evolution of SMBHs and their host galaxies: