Exploring structure around submillimetre-bright QSOs Francisco J. Carrera (IFCA, CSIC-UC, Spain/Imperial, UK) Mathew J. Page (MSSL-UCL, UK) Jason Stevens (CAR, U. Hertfordshire, UK) Rob Ivison (ROE, UK) Serena Falocco (IFCA, CSIC-UC, Spain), Jacobo Ebrero (SRON, NL) MSSL, 14-July- 2010

Outline Introduction: our hard QSO sample –What we now so far about them Environment in submm: strong overdensities Confirmation for RXJ0941 –Radio imaging –SEDs –Presence of AGN –Evolutionary status Summary

Introduction: our hard QSO sample (Page+01,04,10 Stevens+04,05) Sample of Broad Line QSO with X-ray absorbed spectra –At z and L X where most contribution to X-ray background –Matched sample of similar (L X,z) unabsorbed QSO Strong difference in submm fluxes: –Absorbed mostly bright, unabsorbed mostly faint –All submm detected are at z>1.5 –Submm much too bright to come from AGN: strong star formation Absorbed BLQSO are ~10-15% of BLQSO population X-ray-UV spectra: strong ionized winds, enough to terminate SF Simultaneous strong growth of BH and star formation Stronger SF in the past Transitory phase ~10-15% QSO life Just starting to blow away circumnuclear material?

Environment in submm: SCUBA 850  m (Stevens+05,+10) ~400kpc ~2´ 2-4x overdensities Structure in 100skpc Each an ULIRG Some: disturbed morphol. –Major galaxy merger These QSOs are sitting in overdensities in the Universe Submm luminosity from starburst (triggered by fusion/interaction?)

Confirmation for RXJ0941: radio imaging  m sources,  m sources (2 in common): 5 total All in radio (plus blob?) ( Carrera+10 ) iK4.5  m 8  m24  m450  m 850  m 6cm20cm

Confirmation for RXJ0941: photo-z Radio imaging: submm sources real –pinpoint some counterparts Counterparts very faint for spectroscopy Photometric redshifts ( hyperz ): –Fitting spectral templates ( MRR08 ) to RiZJK-4.5,8μm Also tried Bruzual & Charlot 2003: similar z Only fit to rest-frame optical-NIR: no dust –Best if conspicuous feature: between Z and J –M K : bulge (stellar) mass M * from Borys+05 Also used MRR08 (diff M/L): a factor 2-3 larger

Confirmation for RXJ0941: z and SEDs Once z: Spectral Energy Distribution (SED) Using Chary & Elbaz 2001 templates for ≥MIR –Dust emission –Not expected good match to rest-frame Opt.-NIR But surprisingly good… –Not fit: renormalizing to 450μm, 850μm, 4.5μm,… From CE01 templates: –L IR  Star Formation Rate (SFR) (Kennicutt 1998) From 450μm/850μm fluxes: –Assuming (T/ ,  ) (QSO/SMGs Martínez-Sansigre+09)  dust mass

F (cgs/Å) RXJ0941: the QSO 850_1/450_1 iK4.5  m 8  m24  m450  m 850  m 6cm20cm obs (Å) z=1.82 Several components: –AGN direct accretion (MRR+08) –AGN re-processing: torus (MRR+08) –Star formation: L IR ~2x10 13 L  Dominates in MIR/submm SFR~4000M  /y

850_2/450_2 Phot. z=1.85 L IR ~2x10 13 L  SFR~4000M  /y log(M * /M  )~11.6 obs (Å) F (cgs/Å) iK4.5  m 8  m24  m450  m 850  m 6cm20cm Photo-z fit CE01 450μm CE01 850μm

obs (Å) F (cgs/Å) 850_3 Phot. z=1.85 L IR ~0.5x10 13 L  SFR~900M  /y log(M * /M  )~11.5 iK4.5  m 8  m24  m450  m 850  m 6cm20cm Photo-z fit CE01 4.5μm CE01 850μm

Phot. z=1.85 L IR ~10 13 L  SFR~2400M  /y log(M * /M  )~11.5 obs (Å) F (cgs/Å) 450_4 iK4.5  m 8  m24  m450  m 850  m 6cm20cm Photo-z fit CE01 450μm

Phot. z=2.8 L IR ~2x10 13 L  SFR~4000M  /y log(M*/M  )~11.5 iK4.5  m 8  m24  m450  m 850  m 6cm20cm 450_3 obs (Å) F (cgs/Å) Photo-z fit CE01 4.5m CE01 450μm

Table summary Sourcez L IR (10 13 L  ) SFR (M  /y) M dust (10 8 M  ) logM * (logM  ) Flux ( μJy) 450(850)μm 850_1/450_  _2/450_  _ (3  2) 450_  9 450_  8 One spurious expected from logN-logS (Coppin+06) log(M * /M  )~11.5  0.2 (inc.  z and  K) SFR~2000 M  /y M dust ~10 9 M  (interval from  z,  T/ ,  ) –M gas ~5×10 10 M  (Kovács+06 SMG, Seaquist+04 SCUBA)

Presence of AGN X-ray upper limits on soft (6× cgs) and hard (4× cgs) bands: –Using Gilli+07 models –2-10keV luminosity upper limits All 24μm from AGN: very conservative (Elvis+94)  log(L X /cgs)<44 BC~35 (Marconi+04,Elvis+94)  ~0.2 (SMGs z~2 low L X Alexander+08)  log(M BH /M  )<8.1 ( +log(BC/35)-log(  /0.2) ) soft hard

Evolutionary state (Borys+05, Alexander+08, Michalowski+10…) log(M * /M  )~11.5  0.2 (~other SMG samples): –~Schechter mass of MIR-sel gals. (Pérez-González+08) –Gas mass ~10% galaxy mass  Galaxy mature and not much further growth log(M BH /M  )<8.1 ( with  BC,  ) (M BH /M * )/(M BH /M * ) local < 6 (1-100 with  ) (Marconi&Hunt 04) –~1 only if flux at X-ray upper limit and NH>> –L X ~5×10 43 erg/s (SMG Alexander+08), M * ×2 if MRR08…  Growth of BH lags the growth of the galaxy

Evolutionary state Plenty of fuel for AGN growth: -Only ~1.5% of M gas into BH to reach local M BH -M * If BH in exponential growth phase: -Mass e-folding time: t=4.4×10 8 y ×  /  (1-  ) (Martínez-Sansigre & Taylor 09, Rees 84)  =0.2 (low L X SMG Alexander+08)  =0.08 (Marconi+04, M-S&T 09)  M BH ×6 (local): t~340My (over by z~1.65)

Summary We confirmed overdensity around RXJ0941 Counterparts to 4/5 sources at same z –Expected ~1 spurious from submm source counts –HLIRGs, SFR~2000 M  /y Counterparts are massive submm galaxies: –Limited additional growth  Already mature Any AGN must have log(M BH /M  )<8.1 –Below local M BH /M * relationship  Growth of BH lags growth of galaxy Growth of AGN feasible: –Enough fuel –Relatively quickly Need: Herschel to measure submm SED shape (good T/ , M dust …), deeper X-ray to measure MBH, photo-z for the rest…

And there are more... Photo-z successful for 225 –Peak ~1.5-2 –Similar for BC03 89 sources “close” to z=1.82 within 99% with  3 points M * histogram for those 89: –Broad –Narrower if only  M*<1: 8-11 –All three counterparts in highest bins

Interpretation: an evolutionary sequence? More massive DM halos collapse earlier Collisions and mergers occur These processes channel material to the center which –Makes stars –Feeds the BH Material obscures opt/UV (dust) and X-ray (gas) Heated dust emits FIR which escape unimpeded Joint spheroid/QSO evolution within a hierarchical clustering scenario (Granato+04, Silk & Rees 1998, Fabian’99, Di Matteo+05) FIR X-ray

Interpretation: an evolutionary sequence? FIR X-ray FIR X-ray FIR emission increases  ULIRGs Bulk of submm gal. population discovered by SCUBA (Smail+97) ? As BH grows it reaches Sy-like X-ray luminosities Absorbed X-ray sources (Alexander+05) Signatures of buried AGN in opt spec. (Chapman+04) Joint spheroid/QSO evolution within a hierarchical clustering scenario (Granato+04, Silk & Rees 1998, Fabian’99, Di Matteo+05)

Still forming stars (FIR>>) BH allmost fully grown: QSO luminosities QSO radiation and starbursts are starting to sweep out circumnuclear material: Less absorbed X-ray sources  our X-ray absorbed QSOs BALQSOs in slightly later stage? (Fabian’99) Interpretation: an evolutionary sequence? FIR X-ray FIR X-ray FIR X-ray  our X-ray absorbed QSOs Joint spheroid/QSO evolution within a hierarchical clustering scenario (Granato+04, Silk & Rees 1998, Fabian’99, Di Matteo+05)

Interpretation: an evolutionary sequence? FIR X-ray FIR X-ray FIR X-ray Fully grown QSO “living off the rents”  our X-ray unabsorbed QSOs Passively evolving stellar population  our X-ray unabsorbed QSOs Joint spheroid/QSO evolution within a hierarchical clustering scenario (Granato+04, Silk & Rees 1998, Fabian’99, Di Matteo+05)