Arp102B: An ADAF and a Torus

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Arp102B An ADAF and a Torus ?

• Ranga-Ram Chary
• Spitzer Science Center, Caltech

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Introduction Observations

• Arp102B at a distance of 105 Mpc, E0, double
  peaked Ha, radio-loud. SMBH108 M?. NH3E21 cm-2,
  ?1.6, no Fe Ka (Eracleous et al.)
• Keck imaging at 12 and 18 microns (Ho, Scoville,
  Becklin). Seen as a single unresolved source at
  12 microns, sizelt0.6.
• Spitzer IRS spectroscopy with SL (R100), SH, LH
  (R600) between 5-37 microns (part of Spitzer
  Teachers Education Program)
• Spitzer IRS Peak-up on target providing coarse
  photometric calibration with 5 accuracy

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SL and SH spectra of Arp 102B
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The Broadband SED Weak variability evidence
Keck data 2000
F???-1.2
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A Comparison with NGC4258x3
Infrared luminosity is about the same as X-ray
luminosity but x10 higher than UV Fnu?nu-1.2 vs
Fnu? nu-1.4 for NGC4258 L/LEdd2-6E-3 vs L/Ledd
for 1E-4 for NGC4258 Radio spectral index
consistent with alphalt-0.25 (thermal is
alpha-0.4)
Thermal electron distribution
NGC4258 x30 Non-thermal electron distribution ?
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H2 lines detected but offset
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What is powering the emission ?

• OIV/NeII0.2 and FeII/OIV0.86 indicate a
  starburst
• But no PAH present and no silicate..
• NeII/SiIII2.3 and NeIII/ArIIgt3.1 which
  is out of the starburst regime.
• Implies mostly photoionization but 20-30 from
  slow shocks
• Broadband SED consistent with self-Comptonized
  synchrotron emission around a geometrically thick
  accretion flow.

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And the H2 emission ?

• Offset from systemic velocity by 500-1000 km/s
• Not due to wavelength calibration which is O(100)
  km/s but dont have other lines in order to
  check.
• 107 M? of molecular gas in a ring at 1 pc radius
  at a T450K ? Or is it just redshifted emission
  like the He I at 1.083 microns ?

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2-3 pc
Geometrically thick ADAF ?
100 Million M? Black hole
Molecular H2 torus Hot Little star-formation Littl
e dust 107 M?
Double peaked Halpha from the outer disk
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NIR Spectroscopy Rodriguez-Ardila et al. 2006
FeII
H2
FeII
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Rodriguez-Ardila et al. 2006 Strong HeI, SIII,
FeII, SII, H2
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X-ray spectral analysis Eracleous et al. 2003