Do mergers trigger AGNs?

23 Pages·2015·10.35 MB·English

by  Marco Chiaberge

Do mergers trigger AGNs?

Marco
 Chiaberge

 Space
 Telescope
 Science
 Ins4tute

Johns
 Hopkins
 University

Colin
 Norman
 (STScI/JHU),
 Roberto
 Gilli
 (INAF-­‐OABo),
 Jennifer
 Lotz
 (STScI)
DO
 MERGERS
 PLAY
 A
 ROLE
 IN
 TRIGGERING

AGN
 ACTIVITY?

WHAT
 TRIGGERS
 A
 RADIO-­‐LOUD
 AGN?
AGN
 –
 galaxies
 co-­‐evolu4on

 The
 black
 hole
 “awakes”
  AGN/Quasar

Galaxy
 mergers

 Ultra
 luminous
 IR
 galaxy

AGN
 fades

Galaxy
 group

Stars
 evolve

“Normal”
 galaxy
  “Old”
 ellipPcal
 galaxy

Hopkins et al. 2008
the RL/RQ dichotomy
RQ

Kellerman et al. 1989
RL

114 PG QSO
Bimodal distribution?

White et al. 2000, Izevic et al. 2004,
Cirasuolo et al 2007, Balokovic et al 2012

RL/RQ separation
R = F / F = 10
5GHz B

R
 >
 10
 is
 a
 good
 definiPon
 of

radio
 loudness
 for
 QSOs

At low L the threshold shifts
bol
towards higher values R~100
Chiaberge et al. 06, Sikora et al 2007
What is the origin of radio galaxies’ powerful jets?
‏
Spin paradigm (Blandford 1990)

jets are powered by spinning BHs
L ∝ λ2 B2 M2
EM BH

Blandford & Znajek 77, Tchekhovskoy et al. 2011, McKinney et al 2012, Ghisellini et al 2014
Radio Loud rapidly spinning BHs Mergers?
Radio Quiet slowly spinning BHs? Accretion?
Wilson & Colbert 1995, Moderski, Sikora & Lasota 1998, Volonteri et al. 2007, 2013
MERGERS and AGN activity: still debated

Some evidence that some AGNs are more common in close (interacting) pairs
e.g. Silverman et al. 2011, Satyapal et al. 2014, Ellison et al. 2015
Distributions of asymmetry and concentration indices in GOODS show no
connection between recent mergers and X-ray selected AGNs
Grogin et al 2005, Schawinsky et al. 2011
Powerful reddened QSOs at z~2 L ~ 1048 erg s-1 are mergers
bol
Glikman et al. 2015, also Urrutia et al. 2008
Dependence of the AGN merger fraction on luminosity
Treister et al 2011, Glickman et al. 2015
No dependence of AGN merger fraction on luminosity. Less than 40% of the
highest luminosity AGNs may be triggered by mergers (CANDELS)
Villforth et al. 2014
ULIRGs are mergers
Veilleux et al. 2002

Are low – z Radio Galaxies mergers?
Heckman 1986, Colina & de Juan 1995, Ramos Almeida et al. 2012
3CR HST SNAPSHOT survey Cycle 19
12 Radio galaxies +11 QSOs
1 < z < 2.5
Hilbert , Chiab et al. (in prep)

HST WFC3 UVIS F606W + IR F140W

L ~1037 erg s-1 Hz-1
178MHz
L ~ 1046 erg s-1
bol
PI M. Chiaberge
W.B. Sparks (STScI)
G. Miley (Leiden)
A. Capetti (INAF-OATO)
D. Macchetto (STScI)
S. Baum (RIT)
C. O’Dea (RIT)
G. Tremblay (ESO)
E. Perlman (FIT)
A. Quillen (UofR)
Bryan Hilbert (STScI)
JohnPaul Kotyla (STScI-JHU)
C. Stanghellini (INAF-IRA)
E. Torresi (INAF-IASF)
P. Grandi (IAF-IASF)
Adapted form McLure et al 04, Willott et al 2000
POWERFUL RADIO GALAXIES AT z>1
3CR images with HST WFC3/IR F140W
Hilbert , Chiab et al. (in prep)
Chiab, Gilli, Lotz and Norman 2015
WHAT IS THE ROLE OF MERGERS?
Radio loud and radio quiet Type 2 AGNs at 1< z< 2.5 observed with HST- WFC3/IR
LOW LUMINOSITY Radio Galaxies from CANDELS/ECDFS

Bonzini et al. 12, 13
Grogin et al. 2011
Bonzini et al. 2013

Koekemoer et al. 2011

9 Radio galaxies

1030 < P < 4x1032 erg s-1 Hz-1
1.4
q = log(F /F ) <~ 0.1
24 24µm 1.4GHz

L < 1043 erg s-1
2-10keV
Chiab, Gilli, Lotz et al. 2015
WHAT IS THE ROLE OF MERGERS?
Radio loud and radio quiet Type 2 AGNs at 1< z< 2.5 observed with HST- WFC3/IR
LOW POWER Type 2 AGN (RQ) from CANDELS/ECDFS
26 Objects
L < 2 x 1042 erg s-1
2-10keV
HIGH POWER Type 2 QSO (RQ) from CANDELS/ECDFS
9 Objects
L > 1 x 1044 erg s-1
2-10keV
Non Active Galaxies from 3D-HST/GOODS-S
Skelton et al. 14, Grogin et al. 14, Koekemoer et al. 14
~100 Objects
Bright (matched with the 3CR hosts), Faint (matched with RQTY2AGN)
High-mass 1-5x 1011 M
sun