COSMOS 24/100/160 µm (Herschel PEP survey + MIPS)

AGN and the Herschel picture of steady galaxy evolution and starbursts

Galaxies vs. SMBH

Castellammare del Golfo, June 25, 2013

Dieter Lutz

Outline

•  Herschel surveys and the cosmic infrared background

•  Infrared SEDs and the roles of ‘main sequence’ steady evolution and of mergers in the galaxy population out to z~2

•  Rest frame FIR as SF indicator in AGN hosts: strengths and limitations

•  Herschel and star formation in high-z AGN: Results and implications for evolutionary paths

Related to talks by Santini, Rosario, Mullaney, Zamorani, Netzer, Rovilos, Lamastra (at least…) Discussion session later today

PACS Evolutionary Probe (PEP) GT survey: GOODS, COSMOS,….

Data released at http://www.mpe.mpg.de/ir/Research/PEP/public_data_releases.php

Jose Acosta Bruno Altieri Paola Andreani Herve Aussel Stefano Berta Angel Bongiovanni Margherita Bonzini Damien Le Borgne Drew Brisbin Marcella Brusa Hector Castaneda Antonio Cava Jordi Cepa Andrea Cimatti Emanuele Daddi Helmut Dannerbauer Helena Dominguez-Sanchez David Elbaz Emeric Le Floc’h Natascha Förster Schreiber Reinhard Genzel Ignacio Gonzalez Gianluigi Granato Andrea Grazian Carlotta Gruppioni Martin Harwit Ho-Seong Hwang Georgios Magdis Manuela Magliocchetti Benjamin Magnelli Roberto Maiolino

Leo Metcalfe Marco Mignoli Hagai Netzer Raanan Nordon Koryo Okumura Ana Perez Ismael Perez Fournon Albrecht Poglitsch Paola Popesso Lucia Pozzetti Francesca Pozzi Laurie Riguccini Giulia Rodighiero Jose Miguel Rodriguez David Rosario Amelie Saintonge Fadia Salmi Mara Salvato Miguel Sanchez Paola Santini Joana Santos Li Shao Eckhard Sturm Linda Tacconi Margherita Talia Silvia Tomassin Ivan Valtchanov Michael Wetzstein Eckhard Wieprecht Stijn Wuyts

Current deep far-infrared data (4’x4’ cutout in UDF region)

SPIRE SPIRE SPIRE LABOCA

GOODS, PEP, HerMES, LESS

MIPS PACS PACS PACS

Herschel resolves the majority of the Cosmic Infrared Background

Berta+10,11, Magnelli+13, Oliver+10, Clements+10, Bethermin+12…

Resolved into individually detected sources: (~35% @ 70µm) ~75% @ 100µm and 160µm ~15% - 6% @ 250 - 500µm No evidence for a truly diffuse extragalactic background, COBE measurements accounted for

How we looked at (local) infrared galaxies some years ago….

2 MSun/yr Star formation rate 200 MSun/yr disk Morphology major merger low AGN importance high several kpc Extent of star formation few 100pc on Position wrt `main sequence’ above cool Dust temperature from FIR warm high Ratio PAH/FIR low … CO conversion factor ‘Star formation efficiency’ LIR/LCO

Kennicutt-Schmidt relation FIR line deficits …

Normal galaxy LIRG ULIRG

Stellar  mass  

Star  fo

rma,

on  ra

te  

Main  sequence    shi,  for  larger      gas  frac2on  

?  

?  

Tacconi+13

~2007: Something is different at higher z

The ‘IR excess’: z~2 SFRs overpredicted if based on 24µm and local templates SF Template mismatch or obscured AGN? Papovich+07, Daddi+07

z~2 SMGs have stronger PAH than local HYLIRGs, more similar to lower luminosity ULIRGs Lutz+05, Valiante+07, Pope+08,…

The IR ‘excess’ – seen beyond any doubt in first Herschel data

Nordon+ 10 (z~2) Elbaz+10

Better reference than LIR is the ‘main sequence’ of star forming galaxies

Elbaz+11 Nordon+12 =IR/8um

Far-infrared SEDs in relation to the main sequence

TDust increases with MS offset & SSFR [also with decreasing metallicity] Magnelli+ in prep, see also Magdis+12

Molecular gas mass functions since z~3

Berta+ in press 1304.7771: CO mass function using Herschel data and •  Specific attenuation method of Nordon+13 •  PHIBSS depletion time scaling tDep~(1+z)-1

(Tacconi+13)

A hierarchy of star formation indicators:

‘Highest’ SFR: Herschel FIR (+UV) ‘High’ SFR: Spitzer mid-IR (+UV) (Herschel recalibrated) ‘ Low’ SFR: Rest UV/optical SED fitting or recipes Limits between these regimes depend on redshift and

survey practicalities…

Sta

r for

mat

ion

rate

Dus

tines

s

The lesser role of z~2 starbursts

Rodighiero+ 2011

Starbursts: 2% of z~2 massive galaxies

10% of SFR from z~2 massive galaxies All the Rest is on main sequence

A morphological `main sequence’

Wuyts+ 2011.

Is it worth bothering about AGN host SF?

•  Similar cosmic evolution of SF and accretion •  MBH-Mbulge relation

•  Role of AGN in quenching star formation?

Scales: -  Star formation on ~kiloparsec scales -  AGN feeding on <milliparsec -  How to shed the angular

momentum?

Star formation in AGN hosts: some basic questions

•  Is there correlation between accretion rate and star formation rate?

… would indicate a causal link and some level of synchronisation •  What are the controlling mechanisms?

–  Mergers? –  ‘Secular’ disk instabilities and clumps / bars / nuclear spiral structures/

stellar winds

SFR

LAGN

A hierarchy of star formation indicators

‘Highest’ SFR: Herschel FIR (+UV) ‘High’ SFR: Spitzer mid-IR (+UV) (Herschel recalibrated) ‘ Low’ SFR: Rest UV/optical SED fitting or recipes Limits between these regimes depend on redshift and

survey practicalities…

Sta

r for

mat

ion

rate

Dus

tines

s

AGN

To which extent can we trust rest FIR to be host dominated?

Be quantitative!

•  [Approach 0: Models of intrinsic AGN SED? Can produce almost any SED, depending on the imposed dust configuration (which may not be ‘real’)…….]

•  Approach 1: Construct intrinsic AGN SEDs of local AGN, decomposing SEDs of sources with the help of Spitzer-IRS spectra

•  Approach 2: Analyse MIR/FIR vs. FIR/FIR color/color diagrams of AGN+host vs. inactive galaxies

Conclusion from approaches 1+2: In some (in particular luminous) AGN the rest frame FIR can be AGN dominated, but the average emission of typical AGN ensembles under study is dominated by host star formation

Reconstructing intrinsic AGN SEDs

QSO SEDs from Netzer+ 2007 FIR is SF indicator down to L(FIR)~0.1 L(BOL,AGN)

Mullaney+11

COSMOS bright high-z AGN

AGN contribution to FIR: Mid- and far-infrared colors

Hatziminaoglou+10, Rosario+12 (this plot)

The SFR vs LAGN plane: Merger vs. secular?

Rosario+ 2012 (see also Lutz+10, Shao+10, Mullaney+12, Rovilos+12, Page+12, Harrison+12)

The effect of field sizes, depths, (non)detections…

Rosario+12: Fields, and detections vs. stacks of nondetections separated

Large area, luminous AGN, FIR detections only (e.g. Hatziminaoglou+10, Dai+12)

Deep field, moderate luminosity AGN (e.g. Mullaney+12)

Published results consistent once considering specific approach, and field size/statistics

Do we see evidence for quenching at high LAGN??

GOODS-N, Herschel-Spire 250µm (Page+12)

COSMOS XMM AGN z=1…3 250µm detection fractions: All Clean & zspec Log(Lx) 43…44 119/417 29/52 Log(Lx) 44…45 152/484 49/94

Harrison+12

Comparison of SF in AGN hosts to non-AGN galaxies:

•  Compared to in-active galaxies (both SF and passive) of same stellar mass (Santini+12)

‘Enhanced’

•  Compared to the main sequence of star forming galaxies (Mullaney+12, Santini+12, Mainieri+12, Rosario+13)

‘Marginally lower’ ‘Broadly consistent’ ‘Comparable’ •  Most hosts of X-ray AGN from Chandra and XMM surveys

(L2-10<~1044) can be dusty ‘normal’ SF galaxies near the main sequence (Rosario+13)

Different perspective

Mullaney+12 Average SFR and average BHAR f(host mass) in star forming galaxies

Consistency with merger models?

Schematic: Netzer+09 Cox+06, Wuyts+10 merger models (Gadget-2 hydro simulations) Re-visualized into the LSF/LAGN plane Be aware of the underlying assumptions!

‘Secular mechanisms’: clump migration in high-z turbulent disks?

Bournaud+ 11a,b, Gabor+ 13

Averaging, timescales, and variability

When trying to infer controlling mechanisms, be aware of •  Many Herschel studies present average SFRs for a certain population

(sometimes even average BH accretion rates). Intrinsic spread is significant!

•  Timescales: –  AGN variability: <<Myr –  Large host-wide SFR variations convolved with response time of FIR: Ten(s) of Myr –  Galaxy evolution timescales (e.g. shift of MS, decline of SFRD): Gyr –  Possibility of delays SF/accretion

•  Don’t over-average! We started out trying to understand the similarity of cosmic star formation history and accretion history…

Two simple models

Hickox+1306.3218 toy model •  Adopt IR lum. Function (Gruppioni+13) •  Average <SFR>/<BHAR>=3000 •  Fluctuations BHAR/<BHAR> power

law with Schechter cut

Neistein & Netzer 1302.1576 •  SAM in which minor/major mergers

trigger SF bursts, also background SF •  4% of mergers accompanied by near-

Eddington AGN activity •  Different time responses

Fitting the diagram necessary but not sufficient to understand the mechanisms…

Summary

•  Herschel has resolved the cosmic infrared background around its peak •  Like many other properties, IR SEDs of z=0-2 infrared galaxies are best described in

relation to the evolving main sequence of star forming galaxies. Most star formation happens near the main sequence.

•  Good progress in determining mean SFR of X-ray AGN hosts as function of LAGN,z

•  Predominantly secular evolution of AGN hosts, along with inactive ‘main sequence’ star forming galaxies, but mergers likely important at z<1 and high AGN luminosity.