R. Chary, Arp102B, Xi’an Oct ‘06 1/12

Arp102B: An ADAF and a Torus ?

Ranga-Ram CharySpitzer Science Center, Caltech

R. Chary, Arp102B, Xi’an Oct ‘06 2/12

Introduction & Observations

• Arp102B at a distance of 105 Mpc, E0, double peaked Hα, radio-loud. SMBH~108 M. NH~3E21 cm-2, =1.6, no Fe Kα (Eracleous et al.)

• Keck imaging at 12 and 18 microns (Ho, Scoville, Becklin). Seen as a single unresolved source at 12 microns, size<0.6”.

• Spitzer IRS spectroscopy with SL (R~100), SH, LH (R~600) between 5-37 microns (part of Spitzer Teacher’s Education Program)

• Spitzer IRS Peak-up on target providing coarse photometric calibration with 5% accuracy

R. Chary, Arp102B, Xi’an Oct ‘06 3/12

SL and SH spectra of Arp 102BH

2 9.

66 [NeI

I] 1

2.81

[NeI

II]

15.5

6

H2

17.0

3

R. Chary, Arp102B, Xi’an Oct ‘06 4/12

The Broadband SED: Weak variability evidence

Keck data 2000

Fνν-1.2

R. Chary, Arp102B, Xi’an Oct ‘06 5/12

A Comparison with NGC4258x3

NGC4258 x30Non-thermal electron distribution ?

Infrared luminosity is about the same as X-ray luminositybut x10 higher than UV

Fnunu-1.2 vs Fnu nu-1.4 for NGC4258

L/LEdd~2-6E-3 vs L/Ledd for 1E-4 for NGC4258

Radio spectral index consistent with alpha<-0.25(thermal is alpha~-0.4)

3cm 300μm 3μm 300Å 4 keV 400 keV

Thermal electron distribution

R. Chary, Arp102B, Xi’an Oct ‘06 6/12

H2 lines detected but offset

R. Chary, Arp102B, Xi’an Oct ‘06 7/12

What is powering the emission ?

• [OIV]/[NeII]~0.2 and [FeII]/[OIV]~0.86 indicate a starburst

• But no PAH present and no silicate…..• [NeII]/[SiIII]~2.3 and [NeIII]/[ArII]>3.1 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.

R. Chary, Arp102B, Xi’an Oct ‘06 8/12

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 don’t have other lines in order to check.

• 107 M of molecular gas in a ring at 1 pc radius at a T~450K ? Or is it just redshifted emission like the He I at 1.083 microns ?

R. Chary, Arp102B, Xi’an Oct ‘06 9/12

2-3 pc

Molecular H2 torusHotLittle star-formationLittle dust107 M

100 Million M

Black hole

Geometrically thickADAF ?

Double peakedHalpha from the outerdisk

R. Chary, Arp102B, Xi’an Oct ‘06 10/12

NIR Spectroscopy: Rodriguez-Ardila et al. 2006

[FeII] [FeII] H2

R. Chary, Arp102B, Xi’an Oct ‘06 11/12

Rodriguez-Ardila et al. 2006 Strong HeI, [SIII], [FeII], [SII], H2

R. Chary, Arp102B, Xi’an Oct ‘06 12/12

X-ray spectral analysis: Eracleous et al. 2003