The ubiquitous UV murmurs of sleeping supermassive BHs

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The ubiquitous UV murmurs of sleeping
supermassive BHs
Dani Maoz With Neil Nagar, Heino Falcke, Andrew
Wilson
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Peterson et al. (2004)
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High-L accretion physics (geometrically ) thin
accretion disk
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Manners 2002
accretion disk?
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Kormendy Gebhardt 2001
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M32 Ho, Terashima, Ulvestad (2003)
MBH2.5x106 Msun LX1036 erg/s 3x10-9 LEdd
stellar mass loss 10-6 Msun/yr Bondi
accretion 3x10-7 Msun/yr Lacc(e/0.1)1040 erg/s
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if very large or very small, thermal
instability, high T, inefficient cooling, other
accretion solutions geometrically thick
accretion disks
ADAF CDAF ADIOS Outflow RIAF
Ho (2003)
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What is the connection between active and
normal galactic nuclei? (AGNs and NGNs)
How can SMBHs sleep so quietly?
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One way to progress study the subtle signs of
activity from normal nuclei
demographics, accretion physics
SMBH history
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The most common manifestation of
(possibly) non-stellar nuclear activity is
LINERs
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QSO
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Seyfert 1
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Seyfert 2
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LINER (low ionization nuclear emission-line
region)
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SDSS Kaufmann et al. (2003)
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LINERs are very common in bulges
Many of our best friends are LINERs
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M87
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NGC 4594
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At least 1/2 of LINERs have a compact radio
source....
Nagar et al. (2002)
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...at least 1/2 of which are time variable...
Nagar et al. (2002)
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...and at milli-arcsec resolution the cores
remain unresolved TB108K -- and sometimes
have jetlike structures.
Nagar et al. (2003)
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Unresolved (1) nuclear X-ray source...
Terashima Wilson (2003)
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...in about 1/2 of LINERs... Ho et al. (2001)
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...with flux falling on AGN L(Ha) vs LX
relation.
Ho et al. (2001)
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1/4 of LINERs have broad (variable) Ha wings
NGC 4579 Barth et al. (2001)
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But.... -what about all those 1/2s? -many
LINERs have not revealed AGN signatures
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Do LINERs have anything to do with the BH? LINERs
can be excited by Photoionization by an AGN
Ferland Netzer (1983) Halpern Steiner
(1983) Filippenko Halpern (1984) Ho et al.
(1993) Photoionization by stars WR stars
Terlevich Melnick (1985) O-stars Filippenko
Terlevich (1992) Shields (1992) Schultz
Fritsch (1994) Young starburst Barth Shields
(2000) Post-AGB stars Binnette et al. (1994)
Taniguchi et al. (2000) Shocks Koski Osterbrock
(1976) Heckman (1980) Aldrovandi Contini
(1984) Dopita Sutherland (1996)
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Maybe SMBHs and LINERs are both common in
galactic nuclei but an optical LINER spectrum is
not directly related to the accretion process.
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LINER definition based on optical emission
lines Excitation determined by far-UV
light Look in the UV!
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Nuclear UV sources in nearby LINER galaxies
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NGC 404
NGC 3642
NGC 4203
NGC 4258
M81
NGC 4736
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Nucleus is obscured by dust in all LINERs w/0 UV
nucleus Probably all LINERs have UV
nucleus Pogge et al. (2000)
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UV spectrum of LINERs
NGC 4579 Barth et al. (1996)
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Maoz et al. (1998)
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NGC 1741B starburst
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So, how to distinguish stellar from
nonstellar? VARIABILITY! (defining
characteristic of AGNs)
Monitor in UV a sample of LINERs
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Snapshot Monitoring with HST/ACS/HRC in 2002-2003
at 2500 Ang and 3300 Ang
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The sample (all) 17 LINERs with known UV
nuclei L(UV)10(39-41) erg/s
Includes all kinds LINERs 1 / 2, radio / X-ray
detected / undetected, AGN-like /
starburst-like, pure / transition types.
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Big worry detector stability
Boffi et al. 2004 ACS stable in UV to lt 1 !
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Results
historical (510 yr earlier) level
F330 f250
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Summary of results 1. 11/15 vary significantly
on short (month) timescales, typical amplitudes
10 2. Correlated variations in 2500 A and 3300
A 3. Long timescale (years-decade) variations
common, amplitudes factor few 4. Only 3/17 vary
neither on long or short timescales, but even
these may be due to sparse sampling 5. All LINER
types vary
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Conclusion LINERs are indeed genuine signposts
of nonstellar activity (i.e., AGNs). SMBHs in
most normal galaxies are producing (in one way
or another) a LINER spectrum. Variable UV flux
gives lower limit on AGN UV luminosity can
constrain accretion models
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ADAFs predict wrong radio slope radio emission
probably dominated by jets
Nagar et al. (2001)
Also, wrong slope in X-rays Terashima Wilson
(2003) Perhaps UV is also from jets?
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b
NGC 4736 a binary/merging BH?
nucleus
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60 pc
6
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3C 75 7 kpc
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NGC 6240 700 pc
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• Conclusions
• Most LINERs are excited by some nonstellar
  phenomenon near the SMBH (accretion, jets)
• 2. Sharpens demographic picture and allows probe
  of accretion process, hence SMBH growth history
• 3. Possible detection of closest/nearest binary
  AGN

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Ho, Filippenko, Sargent 1993
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Ho (2002)
radio loudness
Lbol/LEdd
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