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Introduction
Photometric analysis
Results
Discussion
Conclusions
Recoiling Super-massive Black Holes, a Search in
the Nearby Universe
Davide Lena
Collaborators:
A. Robinson, A. Marconi, D. Axon, A. Capetti,
D. Merritt, D.Batcheldor, E. Perlman
Rochester Institute of Technology (NY,USA)
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The cosmological perspective
SMBH-binary mergers
In the galactic core
Large scale structures grow
Figure: Millennium Simulation Project. Springel et al. (2005).
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The cosmological perspective
SMBH-binary mergers
In the galactic core
Merging SMBHs
Figure: Time evolution of gravitational radiation during SMBH-binary
merger. Credits: Campanelli, Lousto, Zlochower and Bischof.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The cosmological perspective
SMBH-binary mergers
In the galactic core
Long living BH oscillations
Figure: Long living oscillations in the galactic core, vrecoil & 0.4vesc .
Gualandris & Merritt 2008.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
A Photometric Search
in
Nearby Galaxies
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
What kind of galaxies?
Figure: Regular, bright ellipticals with a nuclear point source from
Balmaverde & Capetti 2005.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
What kind of galaxies?
Figure: Regular, bright ellipticals with a nuclear point source from
Balmaverde & Capetti 2005.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
What kind of galaxies?
Figure: Surface brightness profile with inner deficit (core).
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
What is what?
Minimum of the galactic potential ≡ isophotal center.
BH actual position ≡ nuclear point source.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
The isophotal center
Figure: Galaxy, mask, model → isophotal center.
Isophotal center ≡ BH equilibrium position.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
The Black Hole
Figure: Galaxy, smoothed image, residual → nuclear source.
Nuclear source ≡ BH position
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
The Black Hole - another example:
Figure: Nuclear point-like source.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
From simulations
Precision
0.1 pxl
ACS
HRC WFC
2.5
5
Davide Lena @ D. Axon Memorial Meeting
WFPC2
PC
WF
5
10
NICMOS2
7.5
Recoiling SMBHs, a photometric search
mas
Introduction
Photometric analysis
Results
Discussion
Conclusions
The Sample
Assumptions
Method
Errors estimate
Example - NGC 4261
NGC 4261
Figure: NGC 4261, NICMOS2/F160W, scale=0.05”/pxl.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
Offsets
Results
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
Offsets
Offsets between BH and isophotal center
Statistically significant offsets recovered in 8/14 galaxies:
Galaxy
NGC 4261
NGC 4278
NGC 4486
NGC 4552
NGC 4696
NGC 5419
IC 1459
IC 4296
Davide Lena @ D. Axon Memorial Meeting
Offset (pc)
NPS1
NPS2
3.3 ± 1
5 ± 0.6
7.7 ± 0.5
3.7 ± 0.9
5±1
7±2
5±1
5±1
49 ± 3
62 ± 2
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
On the offset origin
On the Offset Origin
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
On the offset origin
Comparing with simulations
0
0
10
10
−2
10
−2
10
10
NGC 1399
NGC 4168
NGC 4261
−3
10
Assumptions
−1
P(d > x)
P(d > x)
−1
10
−3
NGC 4278
NGC 4373
NGC 4486
−3
−2
10
10
−1
10
10
0
10
−3
−2
10
10
Projected displacement [Rc]
−1
10
0
10
Projected displacement [Rc]
0
vkick ≥ 250 km/s
0
10
10
Tmerger ,q≥0.1 ∼ 1 Gyr
−1
P(d > x)
P(d > x)
−1
10
−2
−2
10
10
NGC 4552
NGC 4636
NGC 5846
−3
10
10
−3
10
−3
−2
10
−1
10
Projected displacement [Rc]
0
10
10
τ=
IC 1459
IC 4296
IC 4931
−3
10
−2
10
−1
10
2
3×107 r30
3.86
σ200
0
10
Projected displacement [Rc]
Figure: Probability to observe a displacement
larger than the value specified on the x-axis.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
yr
Introduction
Photometric analysis
Results
Discussion
Conclusions
On the offset origin
Asymmetries in the jet?
Figure: Jets in M87, IC4296. Credits: NASA, NRAO/NSF, Killeen et al.
(1986).
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
On the offset origin
Double stellar nuclei
Figure: The double nucleus of M31. Lauer at al. (1993).
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
On the offset origin
Several mechanisms could be at the origin of the offset:
Galaxy
Offset (pc)
NGC 4261
NGC 4278
NGC 4486
NGC 4552
NGC 4696
NGC 5419
IC 1459
IC 4296
3.3 ± 1
5 ± 0.6
7.7 ± 0.5
3.7 ± 0.9
5±1
7±2
5±1
5±1
Gravitational
Recoil
Jet
Thrust
X
X
X
X
49 ± 3
62 ± 2
X
X
X
Davide Lena @ D. Axon Memorial Meeting
Suspected Origin
Lopsided
Stalling
Stellar Nuc SMBH-SMBH
X
X
X
X
X
X
X
X
X
X
X
Massive
Perturbers
Resolved
Double Source
X
X
X
X
X
X
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
Conclusions
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search
Introduction
Photometric analysis
Results
Discussion
Conclusions
Conclusions
1
Any evidence for offsets with ∆r ∼ rc in bright ellipticals?
No: ∆r << rc .
2
Simulations suggest that at least one of the following is true:
Typical vrecoil << 250 km/s
Tmerger ,q>0.1 >> 1 Gyr
τ << than expected.
Davide Lena @ D. Axon Memorial Meeting
Recoiling SMBHs, a photometric search