The Spitzer View of Jet-ISM Interactions

1. Patrick Ogle Ski Antonucci, Phil Appleton, David Whysong, & Christian Leipski The Spitzer View of Jet-ISM Interactions

2. Outline • Molecular gas content of radio galaxies. • Spitzer surveys of ISM in radio galaxies. • AGN dust emission. • PAH emission from star-forming regions. • Molecular hydrogen emission from shocks. • Extreme H2 emission from radio galaxies.

3. Jet-ISM Interactions NGC 4258: Spitzer, Chandra,VLA. ~3E39 erg/s in jet shocks. (Yang et al. 2007) 3C 293: 2.2 µm, 1.5 GHz, CO. Possible jet/CO interaction. (A. Evans et al. 1999)

4. Molecular Gas Content of Radio Galaxies 25% of IR-bright z<0.2 RGs detected in CO (A. Evans et al. 2005).

5. Radio Galaxies with Strong CO Evans et al. 2005 • morphological peculiarities • stellar or dust disks • collision/merger activity (Heckman 1986)

6. Radio Morphology Radio jet decollimation HYMORS Compact sources (Labiano, O'Dea...) (Gopal-Krishna 2000)

7. The FRI/II Divide (Owen & Ledlow 1994, Bicknell 1996. ) • Dependence of FR I/II divide on host galaxy luminosity • ISM pressure.

8. Spitzer Surveys of 3C Sources Ogle et al. 2006 IR Lum. Radio Luminosity

9. IR-Luminous vs. IR-weak FR IIs Keck LWS 12 µm images (D. Whysong).

10. Spitzer IR Spectra of Radio Galaxies FR I Radio Galaxies. (Ogle et al. 2007a) • AGNs: Silicate emission, high-ion lines. • Starburst activity: polycyclic aromatic hydrocarbon features.

11. H2 Emission from 3C 326 • Spitzer IRAC images show tidal bridge/tail. • Northern galaxy is extreme H2 emitter. • 3C 326 is 2nd largest known FRII (1.9 Mpc diameter). • Spitzer IRS spectra dominated by pure-rotational H2 lines: L(H2)/LIR=0.15 !! (Ogle et al. 2007b, ApJ, submitted)

12. 3C 326 SED • Stellar emission J, H, and K bands. • Mid-IR dust emission from weak star-formation (2E-2 Msun/yr). • Radio cores and lobes

13. H2 Shock-Excitation in 3C 326 • L(H2)=8E41 erg/s • T(H2)=125,400,1000 K • M(H2)=1.1E9 Msun • Ortho/Para H2=2.1-3.0 L(jet kinetic) ~ 1E44 erg/s, mostly dissipated in Mpc-scale lobes. L(grav. inflow) ~ 3E42 erg/s from 12 Msun/yr Ogle et al. 2007b

14. Shocked H2 Emission in 3C 293 Spitzer IRAC and IRS • L(H2)=6E41 erg/s, • L(178 MHz)=1E41 erg/s • M(H2 warm, cold)=1E9, 1.5E10 Msun • HI and ionized outflows (Morganti et al. 03,05) Ogle et al. 2007c

15. More Radio Galaxies with strong H2 25% of FR Is have strong H2! 6% of FR IIs. (Ogle et al. 2007c)

16. Molecular Hydrogen Emission Galaxies • Stephan's Quintet intergalactic shock (Appleton et al. 2006). • Zw 3146 X-ray cluster cD (Egami et al. 2006). • 5 FR Is, 3 FR IIs Including 3C 326, 3C 293 (Ogle et al. 2007c) MOHEG's: L(H2) >1E40 erg/s L(H2)/L(IR)>1E-3

17. MOHEGs—Gas Rich Mergers? 3C 84, 293, 310 3C 315, 317, 326 3C 338, 386, 433 HST WFPC2 snapshots (PI Sparks)

18. What Powers the H2 Emission? • AGN X-rays -In most cases the AGN is not powerful enough. Chandra data needed!! • Radio Jet ---jet powers are large enough, but also require: a) Large dissipation in host ISM, affecting morphology. b) Large energy conversion efficiency to heat H2. • Tidally-induced Accretion from a Companion a) Companions and interaction/mergers prevalent. b) Gravitational potential energy abundant. c) Problem(?)—shocks must be non-dissociative d) Why is the phenomenon so common in RGs (?)

19. Future Directions COMING SOON: • Ground-based imaging of near-IR rovibrational lines. • Spitzer IRS High-Resolution spectra of H2 lines—kinematics. DESPARATELY NEEDED: • High spatial-resolution imaging (VLBI) of radio cores. • AGN X-ray fluxes (Chandra). • CO observations to estimate cold H2 mass. • THEORY! Can jets heat 1E9 Msun of H2 to 1000 K??