Fast-Growing Black Holes in Fast-Growing Galaxies, at z~5 the role of mergers revealed with ALMA Benny Trakhtenbrot (ETH Zurich) with: Paulina Lira (U. Chile), Hagai Netzer (Tel-Aviv U.), Claudia Cicone (INAF Brera), Roberto Maiolino (Cambridge), Ohad Shemmer (U. North Texas) SMG20 meeting, Durham, 2-Aug-2017
SMBHs at all cosmic epochs plot adapted from Trakhtenbrot & Netzer 12 ULAS J1120 z=7.1(2011) 1. How did SMBHs form so early, so massive? 2. How did they grow so quickly?
How to grow a SMBH in ~1 Gyr? reviews on BH seeds: plot adapted from Volonter 10, Natarajan 11 Trakhtenbrot & Netzer 12
How to grow a SMBH in ~1 Gyr? reviews on BH seeds: plot adapted from Volonter 10, Natarajan 11 Trakhtenbrot & Netzer 12
Major galaxy mergers and (early) SMBH growth Sanders+88, Hopkins+08
… but mergers are not the only way! “ Violent disk instabilities ” “Cold streams” • Stream host gas (~5 kpc) to nuclei Stream ambient gas (>100 kpc) to nuclei • • More relevant at high redshifts • More relevant at high redshifts (high gas densities) (in over-dense regions) Bournaud+11 Dekel+09, Di-Matteo+12, Dubois+12
Large-scale environments of early SMBHs simulations average density, z~6 high density, z~6 from Costa+14 HST/ ACS FOV • Simulations suggest early BH mass growth favors over-dense environments • Can be tested by counting the number of galaxies around SMBH hosts • So far, few systems studied, with ambiguous results (Willott+05, Overzier+06, Kim+09, Utsumi+10, Husband+13, Banados+13, Simpson+14, Kikuta+17 … )
Observing the early, rapid growth of SMBHs 1. Identify fast-growing SMBHs in the early universe 2. Resolve their host galaxies and environments
A large sample of fast growing SMBHs at z~4.8 log M BH log L/L Edd 40 luminous quasars at z~4.8 with M BH ~10 9 M ☉ and L/L Edd ~0.8 M BH = 4 10 7 4 10 8 1.5 10 9 M samples from: Shemmer+04, Netzer+07, Kurk+07, Dietrich+09, Marziani+09, Trakhtenbrot & Netzer 12 Willott+10, Trakhtenbrot+11 , DeRosa+14 …
A large sample of fast growing SMBHs at z~4.8
Herschel imaging: extreme SF in z ~4.8 quasars • All 40 z~4.8 quasars imaged with Herschel/ SPIRE (rest-frame ~40-90 μ m) • Detection in 10 hosts ( S 500 ~13-50 mJy ) and in stack of the other 30: ~¼ have SFR~2000-4000 M ☉ /yr ~¾ have SFR~ 450 M ☉ /yr • Low spatial resolution: ~120 kpc Mor+12, Netzer+14
Herschel imaging: extreme SF in z ~4.8 quasars • All 40 z~4.8 quasars imaged with Herschel/ SPIRE (rest-frame ~40-90 μ m) • Detection in 10 hosts ( S 500 ~13-50 mJy ) and in stack of the other 30: ~¼ have SFR~2000-4000 M ☉ /yr ~¾ have SFR~ 450 M ☉ /yr • Low spatial resolution: ~120 kpc wide range of host properties … Mergers vs. “ secular ” systems? Mor+12, Netzer+14
(~20 years of) Resolving hosts and mergers for z~ 5 quasars BR 1202-0725 Iono+06, 20 hours, SMA luminous quasar, z=4.7 S 900 ~ 30-60 mJy Omont+96 16 hours, PdBI Wagg+12 25 minutes, ALMA SV
ALMA Observations of fast-growing SMBHs, at z ~4.8 Six fast-growing z~4.8 SMBHs observed w/ALMA (cycle-2, band-7, ~0.3 ” ) ALMA resolves the dusty, • star-forming host galaxies of early SMBHs SMBH host Trakhtenbrot+17 ( ApJ , 836, 8)
ALMA Observations of fast-growing SMBHs, at z ~4.8 Six fast-growing z~4.8 SMBHs (ALMA cycle-2) Herschel ALMA SMBH host SMBH host galaxy at z=4.8 SFR = 360 M / yr Trakhtenbrot+17
ALMA Observations of fast-growing SMBHs, at z ~4.8 Six fast-growing z~4.8 SMBHs (ALMA cycle-2) SMBH host 3 mJy SMBH host galaxy at z=4.8 3 mJy → SFR = 360 M / yr [CII] line → M dyn 7 10 10 M Trakhtenbrot+17
ALMA Observations of fast-growing SMBHs, at z ~4.8 Six fast-growing z~4.8 SMBHs (ALMA cycle-2) [C II] 158µm line spectrum SMBH host galaxy at z=4.8 SMBH M dyn,QSO 7 10 10 M , SFR =360 M / yr host 3 mJy companion SMG 1.2 mJy interacting galaxy Trakhtenbrot+17 M dyn,SMG 2 10 10 M , SFR =150 M / yr
ALMA Observations of fast-growing SMBHs, at z ~4.8 • A high fraction of companion (interacting) SMGs: ~50% Separations of ~15-50 kpc and < 450 km/s from quasar hosts • All are “ major mergers ” ; not seen in previous Spitzer /IRAC data • Trakhtenbrot+17 High- z , fast-growing SMBHs are found in over-dense environments
ALMA Observations of fast-growing SMBHs, at z ~4.8 Six fast-growing z~4.8 SMBHs (ALMA cycle-2) • Mergers are not unique drivers of intense SMBH and galaxy growth SMBH SMBH host galaxy host 18.5 mJy SFR ~ 3000 M /yr Trakhtenbrot+17
ALMA Observations of fast-growing SMBHs, at z ~6 Decarli+17: ALMA observations of 25 fast-growing z~6 SMBHs 4 of the 25 have nearby companions (~8-60 kpc) NIR / sub-mm sub-mm / CII 158 m High- z , fast-growing SMBHs are found in over-dense environments
On-going and future observations • Getting a larger sample with ALMA data observing 12 more targets in ALMA cycle-4, bringing total to 18 • Resolving late-stage and/or minor mergers, and host kinematics deep, higher-resolution ALMA observations, reaching sub-kpc scales • Probe large-scale environments of quasars – are these proto-clusters? HST/ WFC3-IR imaging out to d~400 kpc Subaru/HSC multiband imaging for Lyman-break galaxies (d~10 Mpc) • Search for dual AGN in the interacting SMGs Chandra X-ray follow-up of interacting systems
Summary • A large sample of fast-growing SMBHs at z~4.8, rich multi- dataset • Hershel data suggests high SFRs, reaching SFR>1000 M ☉ /yr. wide range of host properties different fueling mechanisms? • ALMA spectro-imaging resolves SF and ISM dynamics at ~2-50 kpc scales. • We find interacting companion SMGs for (>)50% of quasar hosts High redshift quasars grow in over-dense environments • But major mergers are probably not a unique mechanism for driving the fastest growth of the SMBHs and their hosts: How to trigger a quasar from 40 kpc away? – – How to get SFR>1000 M ☉ /yr from “ secular ” processes? How to fuel nearly-continuous SMBH growth? – – Are we seeing proto-clusters? or do these structures “ normalize ” later? On-going and future observations will enlarge sample, probe large scale • environments, and search for dual AGN in companions
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