Fast-Growing Black Holes in Fast-Growing Galaxies, at z~5 the role - - PowerPoint PPT Presentation

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

ULAS J1120 z=7.1(2011)

• 1. How did SMBHs form so early, so massive?
• 2. How did they grow so quickly?

plot adapted from Trakhtenbrot & Netzer 12

plot adapted from Trakhtenbrot & Netzer 12 reviews on BH seeds: Volonter 10, Natarajan 11

How to grow a SMBH in ~1 Gyr?

How to grow a SMBH in ~1 Gyr?

plot adapted from Trakhtenbrot & Netzer 12 reviews on BH seeds: Volonter 10, Natarajan 11

Sanders+88, Hopkins+08

Major galaxy mergers and (early) SMBH growth

“Violent disk instabilities”

• Stream host gas (~5 kpc) to nuclei
• More relevant at high redshifts

(high gas densities) Bournaud+11 Dekel+09, Di-Matteo+12, Dubois+12

“Cold streams”

• Stream ambient gas (>100 kpc) to nuclei
• More relevant at high redshifts

(in over-dense regions)

… but mergers are not the only way!

Large-scale environments of early SMBHs

• 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…)

average density, z~6 high density, z~6

HST/ ACS FOV

simulations from

Costa+14

• 1. Identify fast-growing SMBHs in the early universe
• 2. Resolve their host galaxies and environments

Observing the early, rapid growth of SMBHs

Trakhtenbrot & Netzer 12 samples from: Shemmer+04, Netzer+07, Kurk+07, Dietrich+09, Marziani+09, Willott+10, Trakhtenbrot+11, DeRosa+14 …

MBH= 4107 4108 1.5109 M

log MBH log L/LEdd

40 luminous quasars at z~4.8 with MBH ~109 M☉ and L/LEdd ~0.8

A large sample of fast growing SMBHs at z~4.8

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 ~40-90μm)

• Detection in 10 hosts (S500~13-50 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 ~40-90μm)

• Detection in 10 hosts (S500~13-50 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

 wide range of host properties… Mergers vs. “secular” systems?

Wagg+12 25 minutes, ALMA SV

(~20 years of) Resolving hosts and mergers for z~5 quasars

Iono+06, 20 hours, SMA

BR 1202-0725

luminous quasar, z=4.7 S900 ~ 30-60 mJy

Omont+96 16 hours, PdBI

ALMA Observations of fast-growing SMBHs, at z~4.8

• ALMA resolves the dusty,

star-forming host galaxies of early SMBHs

SMBH host

Six fast-growing z~4.8 SMBHs observed w/ALMA (cycle-2, band-7, ~0.3”)

Trakhtenbrot+17 (ApJ, 836, 8)

SMBH host

SMBH host galaxy at z=4.8 SFR = 360 M / yr

ALMA Observations of fast-growing SMBHs, at z~4.8

ALMA Herschel

Trakhtenbrot+17

Six fast-growing z~4.8 SMBHs (ALMA cycle-2)

SMBH host galaxy at z=4.8 3 mJy → SFR = 360 M / yr [CII] line → Mdyn  71010 M

ALMA Observations of fast-growing SMBHs, at z~4.8

Trakhtenbrot+17

Six fast-growing z~4.8 SMBHs (ALMA cycle-2)

SMBH host 3 mJy

SMBH host 3 mJy

SMBH host galaxy at z=4.8 Mdyn,QSO  71010 M , SFR =360 M / yr

[C II] 158µm line spectrum

interacting galaxy Mdyn,SMG  21010 M , SFR =150 M / yr

ALMA Observations of fast-growing SMBHs, at z~4.8

Trakhtenbrot+17

Six fast-growing z~4.8 SMBHs (ALMA cycle-2)

companion SMG 1.2 mJy

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

• Mergers are not unique

drivers of intense SMBH and galaxy growth

SMBH host galaxy SFR ~ 3000 M /yr

SMBH host 18.5 mJy

ALMA Observations of fast-growing SMBHs, at z~4.8

Trakhtenbrot+17

Six fast-growing z~4.8 SMBHs (ALMA cycle-2)

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