Transcript "It takes 2 to Tango - Merging AGN caught in the Act"

It Takes Two to Tango:
a Panchromatic View
of Merging Black Holes
Francesca Civano
Harvard Smithsonian Center for Astrophysics
Outline
• Introduction: The Merging Tango
• Dual AGNs
– The Chandra view of Dual AGNs
• Binary BHs
• GW Recoiling BHs
• CID-42 a candidate Recoiling BH
– Optical Spectra
– Chandra X-ray Imaging
– Chandra & XMM X-ray spectroscopy
• Summary
The Galaxy/BH co-evolution
Double ACTIVE SMBH in a single
galaxy:
(e.g.Volonteri et al. 2003, Hopkins et al. 2008, Colpi
& Dotti 2009)
• Common
at z=2

Cosmic
Cycle
but hard
to detect
Hopkins
et al. 2008
• Rare at low z
easier to detect
The Merging Tango
3 Phases of the
Merging process:
-kpc separation
Dual AGN
-pc separation
Binary AGN/SMBH
- After the Coalescence
 Recoiling SMBH
Credit to CXC and G. Di Milia
Large separation: Dual AGNs
Active
At large relative separations 2 - 20 kpc
Not physically bound
Dynamics is determined by the gravitational potential of
the interacting system
How to detect them:
1) Optical Spectroscopy (Gerke+2007, Comerford+2009,
Hennawi+2010, Liu+2010 )
WARNING: double-peaked features could be due either to
NLR kinematics such as outflows or rotating disks
2) Optical Imaging (Liu+2011)
 ALONE it is not enough!
3) X-ray Imaging (Chandra: Komossa+2003, Bianchi+2008,
Ballo+2004, Green+2010; XMM: Piconcelli+ 2011)
 THE DETECTION of hard X-ray emission unambiguously reveals the
presence of 1 or 2 BHs
Chandra View of Dual AGNs
The Chandra unrivaled spatial resolution
allows to resolve and confirm Dual AGNs,
in particular the obscured ones.
NGC 6240
Komossa+2003
2.5 kpc
(1.8”)
Mrk 463
Bianchi+2008
3.8 kpc
(3.8”)
Arp 299
Ballo
+2004
4.6kpc
(22”)
SEPARATION (kpc)
SDSSJ114642+
511029
Liu+2010
Shen+in prep.
5.5kpc
(2.5”)
SDSSJ1254+
0846
Green+2010
21 kpc
(4”)
z=0.44
Chandra Image
NGC 6240
Komossa+2003
Mrk 463
Bianchi+2008
Composite
2.5 kpc X-ray + Optical
3.8 kpc
4”
3.8”
Arp 299
Ballo
+2004
SDSSJ114642+
511029
Liu+2010
SDSS Optical
Image
4.6kpc
5.5kpc
22”
2.5”
SEPARATION (kpc)
SDSSJ12
54+0846
Green+2010
21 kpc
4”
r band z=0.13
0.3-10 keV
0.5-2 keV
First result from a sample of 4
DUAL
AGNs (Liu+2010)
NGC 6240
Mrk 463
Arp 299
Komossa+2003
Bianchi+2008
1. discovered
in SDSS Ballo
2. confirmed as AGN in+2004
NIR
kpc
kpc
4.6kpc
3. 2.5observed
by 3.8
Chandra
during
4”
3.8”
22”
Cycle 12 (Shen+
in
prep)
SEPARATION (kpc)
SDSSJ114+
5110
Liu+2010
Shen+in prep.
5.5kpc
2.5”
2-10keV
SDSSJ1254+
0846
Green+2010
21 kpc
4”
Powerful local (D=44Mpc) IR merging
system discovered by Beppo Sax
and spatially resolved by Chandra
Chandra Soft X-ray
IC 694 (left)  Starburst galaxy +
NGC 3690 (right)  LINER
22”
Chandra Hard X-ray
NGC3690:
TwoMrk
knots
NGC
6240
463 in
Komossa+2003
Bianchi+2008
the soft band one
of
which disappear in the
hard
band
2.5 kpc
3.8 kpc
4”
3.8”
Arp 299
Ballo
+2004
4.6kpc
22”
SEPARATION (kpc)
SDSSJ114642+
511029
Liu+2010
Shen+in prep.
5.5kpc
2.5”
22”
Arp 299
Ballo
+2004
21 kpc
4”
Mrk E: Optical Seyfert 2
Mrk W: SB galaxy
Mrk 463 z=0.05
Hard Spectra
E Iron line
W
with Strong
and NH~1023 cm-2
3.8”
2-10 keV X-ray Image
NGC 6240
Mrk 463
Komossa+2003
2.5 kpc
4”
Bianchi+2008
3.8 kpc
3.8”
Arp 299
Ballo
+2004
4.6kpc
22”
SEPARATION (kpc)
SDSSJ114642+
511029
Liu+2010
Shen+in prep.
Arp 299
Ballo
+2004
Chandra
on [OIII] map
5.5kpc Soft X-ray
21 kpc
2.5”
4”
Hard Spectra
with Iron line
detection,
indication of
nuclear
emission
NGC6240 z=0.024
Northern Nucleus
Southern Nucleus
NGC 6240
Komossa+2003
1.3 kpc
1.8”
Mrk 463
Bianchi+2008
3.8 kpc
3.8”
Arp 299
Ballo
+2004
4.6kpc
22”
SEPARATION (kpc)
SDSSJ114642+
511029
Liu+2010
Shen+in prep.
5.5kpc
2.5”
Arp 299
Ballo
+2004
21 kpc
1.8”
4”
X-ray image
Small Separation: Binary BHs
& Lauer 2009
active BHsBoroson
De Carli +2010
Very close: ~ few pc or sub-parsec
Physically bound
Keplerian system
High velocity offsets few x 103
 Derive the orbital period
Δv~3500km/s
Few candidates have been discovered through optical spectroscopy
by detection of high velocity offset emission line systems:
EASY TO DETECT because of large optical Doppler Shift in emission lines
BUT VERY RARE!!
 NO WAY toWrobel
get X-ray
emission
from the
two
sources separately
& Laor
2009; Decarli
et al.
2009;
Tang & Grindlay 2009; Chornock et al. 2010
After the Merging
Under particular condition of mass ratio and BH spin alignment
 Asymmetric emission of GW SMBH Recoil
(Peres 1962, Bekenstein 1973)
Substantial velocities (up to 4000 km/s,
Campanelli+ 2007, Lousto +2011, Blecha+ 2011)
1) v> vescape isolated SMBHs
2) v<vescapeoffset SMBHs
The lifetime depends on the amount
Credit: T. Jones/McDonald Obs.
of accreting material around the BH
The BH never gets large separation before fading
Probability for GW kick
Number counts
of kicked AGNs
in surveys
(for different λE , disc)
CDF-S: SMALL AREA 
Max 1 GW recoiling BH
COSMOS:
LARGE AREA 
a few sources.
Volonteri & Madau 2008
Large Kick
Long active phase
GW Recoiling SMBH Candidates
Intensive searches (Bonning et al. 2007) few candidates
(Doppler shifting)
1. SDSSJ092712.65+294344.0 (Komossa et al. 2008)
2. SDSS J105041.35+345631.3 (Shields et al. 2009)
SPECTROSCOPY
CID-42: candidate GW recoiling SMBH with both
(displaced quasars)
IMAGING
SPECTROSCOPY
and IMAGING signatures
3. z=0.047
SDSS galaxy
et al. 2010)
detected
in the(Jonker
Chandra-COSMOS
survey
4. M87 (Batcheldor et al.
2010)
(Civano
et al. 2010)
POLARIMETRY
5. Quasar E1821+643 (Robinson et al. 2010)
CID-42 properties
N
A peculiar source in 3 ways:
CID-42
E
1. Two sources in the optical
image.
2. Two emission line systems
with a large >1000km/s
velocity offset
3. A variable redshifted
absorption iron line
HST image
(Civano et al. 2010)
(see also Elvis 2009 and Comerford et al. 2009)
Optical spectroscopy -1
z=0.359
3 optical spectra with high S/N :
•1 Magellan/IMACS R=700
•2 VLT/VIMOS R=700
Offset between broad
and narrow Hβ:
Δv~1100 km/s
Model
λ(Angstrom)
Optical spectroscopy - 2
Previous claim (Comerford et al. 2009) based on two systems of
narrow lines ([OIII] and Halpha):
Dual AGNs with Δv=300 km/s
Hβ
[OIII]
doublet
DEIMOS Keck
2 mins
exposure
R=2700
LOW S/N
NII
Hα
NII
Optical spectroscopy - 3
DEIMOS Keck
45 mins
S/N=20
R=2700
Hβ Hβ
[OIII]
NII Hα NII
• NO: double [OIII] and Halpha narrow line system
•YES: Hβ offset
SE source has a point like opt. profile
 Plays the role of the type 1 AGN
 Produces the BL
 Moves away from the Galaxy center
1 SMBH
predicted
NW
SE
Ejected BH
NW source has an
extended opt. profile
Plays the role of the
galaxy bulge
NOW without a BH
X-ray emission:
test for the presence of
1 or 2 active BHs (recoiling BH or NOT?)
HST/ACS
Chandra/ACIS 0.5-2keV
4’ off-axis
PSF size 2”
Cycle 12, Feb. 2011
HRC (0.15” PSF)
80 ksec
Civano et al. ApJL in prep.
ACIS-I
4’ off-axis
PSF size 2”
Only 1 AGN detected  GW RECOIL
Cycle 12
HRC (0.15” PSF)
80 ksec observation
SE source 318 counts
NW source < 3% (9 counts at 3sigma)
Civano et al. ApJL in prep.
Credit to L. Blecha
Time since recoil ~3-4 Myr
1:2 mass ratio merger
14 Myr after the BH merger Consistent with the life time
of a disc of 2-3% the BH mass
 vrecoil>~1.5 vescape
and BH accreting at 0.04Edd
Normal X-ray spectra but….
Stacked spectra
Gamma=1.95±0.07
NH<2x1020 cm-2
Lx=2x1043 erg/s
Continuum
Variability
Emission + Absorption
Detected in 3 instruments
from 2 satellites
XMM
~2200 counts
Chandra
~800 counts
FeK Inverse P-Cygni profile
XMM
Fe-K Emission
Absorption
Narrow emission Line
• EW=570 eV
Chandra
Absorption Line
•EW= 440 eV
• Redshifted
• Broad in XMM
( =200 eV)
• Narrow in Chandra
3 known redshifted absorption lines in the literature:
Mrk 335 (Longinotti+2007) , PG 1211+143 (Reeves+2005), Mrk
509 (Dadina+2005)
Broad or Narrow Line? (1)
NARROW Absorption Line!!!
Broad or Narrow Line?(2)
NARROW and variable energy in time
INFLOW of material at
~few Rs changing:
• Velocity : 0.02-0.07c for
FeI, 0.09-0.14c for FeXXVI
or
•Ionization state:
FeI  FeXXVI (E=500 eV )
E~450 eV =>105km/s /yr
•BOTH
New long (123 ks) XMM observation coming soon!
Summary
 Finding Dual AGNs is of extreme importance to support theoretical
models of galaxy/BH co-evolution
 Coupling optical observations with X-ray one is needed to confirm
the active nature of Dual AGNs
 Chandra superb resolution allows us to study the BHs in the
closest phases of the merging, where other observations are not
conclusive
 CID-42 GW recoiling SMBH: Spectroscopy and imaging signature
 Chandra HRC imaging: 1 X-ray emitting “AGN” offset from the
galaxy center