Molecular Gas in Low-Redshift Radio Galaxies & Quasi-Stellar Objects Detected by IRAS Aaron Evans (Stony Brook) J. Mazzarella (IPAC) J. Surace (SSC) D. Frayer (SSC) K. Iwasawa (Cambridge) D. Sanders (U. Hawaii) T. Vavilkin (Stony Brook) P. Solomon (Stony Brook) P. Solomon (Stony Brook) D. Downes (IRAM) D. Downes (IRAM) L. Tacconi (MPE Garching) L. Tacconi (MPE Garching)
Motivation What is the evidence that links classical, luminous UV and radio- selected AGN with infrared luminous galaxy mergers? What is the evidence that links classical, luminous UV and radio- selected AGN with infrared luminous galaxy mergers? Support circa 1990: Support circa 1990: 1) a large fraction of classical QSOs and radio galaxies were detected by IRAS (e.g. Golombek et al. 1988; Sanders et al. 1989) 1) a large fraction of classical QSOs and radio galaxies were detected by IRAS (e.g. Golombek et al. 1988; Sanders et al. 1989) 2) evidence of merger/interaction morphologies in the host galaxies of QSOs and radio galaxies (e.g., Stockton & MacKenty 1984; Heckman et al. 1986; Sanders et al. 1988; Smith & Heckman 1990a,b) 2) evidence of merger/interaction morphologies in the host galaxies of QSOs and radio galaxies (e.g., Stockton & MacKenty 1984; Heckman et al. 1986; Sanders et al. 1988; Smith & Heckman 1990a,b) 3) CO(1-0) detections of several QSOs and radio galaxies (Philips et al. 1987; Sanders et al. 1988b; Barvainis et al. 1989; Mirabel et al. 1989a,b; Alloin et al. 1992) 3) CO(1-0) detections of several QSOs and radio galaxies (Philips et al. 1987; Sanders et al. 1988b; Barvainis et al. 1989; Mirabel et al. 1989a,b; Alloin et al. 1992)
Selection Criteria PG QSOs with PG QSOs with L IR / L m > 0.46 (Surace et al. 2001). L IR / L m > 0.46 (Surace et al. 2001). z < 0.16 z < 0.16 M B < M B < Total of 17 objects Total of 17 objects IRAS-detected radio galaxies in Golombek et al with f 60 or f 100 > 0.3 Jy. z < 0.13 Total of 32 objects QSOsRadio Galaxies Note: For PG QSOs, L IR = ( )L bol Note: For PG QSOs, L IR = ( )L bol
Observations Two transits per source Two transits per source 4” beam 4” beam Detection Limit of S CO (3 rms) = 8 mJy with 280 km s -1 smoothing Detection Limit of S CO (3 rms) = 8 mJy with 280 km s -1 smoothing I.e., M(H 2 ) = 10 9 M sun at z = 0.1 I.e., M(H 2 ) = 10 9 M sun at z = hours per source Detection limit L’ CO (3 rms) ~ 6x10 8 K km s -1 pc 2 for 250 km s -1 line QSOs Radio Galaxies (Evans et al. 2001, 2005b) (Mazzarella et al. 1993; Evans et al. 2005a)
QSO Host Galaxies 50% Spiral-like hosts with & without bars 25% Clear major mergers 25% Featureless/Elliptical-like galaxies (Surace, Sanders & Evans 2001) PG PG PG PG IZw1 PG PG PG BI Images
Radio Galaxies UBI Images - UH 2.2m Mixture of Mergers, Spiral Galaxies, and Elliptical Galaxies (Evans et al. 2005)
Molecular Gas in PG QSOs: Examples 10 out of 15 QSOs (2 by Scoville et al. 2003) PG PG PG PG
QSOs: IRAM 30m Telescope Follow-Up M(H 2 ) ~ x10 9 M sun ( = (4 K km s -1 pc 2 ) -1 M sun ) v FWHM ~ 260±160 km s -1 (for ULIGs ~ 300±90 km s -1 ) Some of the lines are extremely narrow PG has a featureless host galaxy IRAM 30m, see also Sanders et al. 1988b; Barvainis et al. 1989; Alloin et al. 1992; Evans et al. 2001; And Scoville et al. 2003
Molecular Gas in Radio Galaxies: Examples Nine of 32 detected. x sun ( = (4 K km s -1 pc 2 ) -1 M sun ) Many double peaked profiles - absorption, molecular rings v FWHM ~ 500±130 km/s (Previous detections: Phillips et al. 1987; Mirabel & Sanders 1989) NRAO 12m
Radio Galaxies: Massive Host Galaxies + Extended Disks (S CO v) OVRO consistent within single-dish measurements Sizes ~ 2-8 kpc M dyn ~ 0.2-1x10 11 M sun M(H 2 )/M dyn ~ SB ~ M sun /pc 2 Also, N(H 2 ) ~ 1-6x10 22 cm -2, consistent with X- ray N(H 2 )
1. Global L’ CO -L IR trends
2. What are the star formation rates of these galaxies? If L IR ~ L(SB), SFR(L IR ) ~ M sun yr -1 If L IR ~ L(SB), SFR(L IR ) ~ few-200 M sun yr -1 (mostly tens of M sun yr -1 ) SFR( gas ) ~ 2-7 M sun yr -1 kpc -2 ~ 5-50 M sun yr -1 (see review article of Kennicutt 1998 for discussion of SFR determinations) QSOs Radio Galaxies
3. L IR /L’ HCN as a tracer of L AGN vs. L SB L IR /L’ HCN ~ 880±500 (Gao & Solomon 2004)
HCN Spectra of PG QSOs
Is L IR ~ L(SB)?? Maybe L(SB) ≤ 0.25L IR for QSOs
Near(ish) Future CO(1-0) surveys of volume-limited samples of classical AGN (e.g. Scoville et al. 2003; Lim et al. 2000) CO(1-0) surveys of volume-limited samples of classical AGN (e.g. Scoville et al. 2003; Lim et al. 2000) HCN surveys of CO-luminous AGN with GBT, LMT HCN surveys of CO-luminous AGN with GBT, LMT High-resolution 1mm observations of CO-luminous AGN with CARMA, SMA, etc. High-resolution 1mm observations of CO-luminous AGN with CARMA, SMA, etc.