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Impact of Jet Feedback on H 2 and Star Formation in Radio Galaxies Patrick Ogle (Caltech, Spitzer Science Center) R. Antonucci, C. Leipski, Phil Appleton, Francois Boulanger
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Normal Star-Forming Galaxies Spitzer SINGS survey of nearby galaxies (Smith 07). Polycyclic Aromatic Hydrocarbon (PAH) dust is excited by UV in stellar photodissociation regions. PAH emission is useful for estimating star-formation rates in AGN hosts. The 7.7 um feature is not excited by AGN activity. H 2 emission is weak. PAHs H2H2
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Radio Galaxies with Extreme H 2 Spitzer IRS radio galaxy survey: 17/57 (30%) of 3C radio galaxies at z<0.2 have strong H 2 ! Environment: 14/17 have close or interacting companions. 6/17 live in cool-core clusters. (Ogle et al. 08, in prep.)
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Radio Galaxy 3C 326 (z=0.089) ● Spitzer IRS spectrum dominated by pure-rotational H 2 lines: ● L(H 2 )=8 10 41 erg/s ● L(H 2 )/LIR~0.05-0.1 ● M(H 2 )=1.1 10 9 M (Ogle et al. 2007) Spitzer IRAC: galaxy pair (sep. 42 kpc), connected by tidal bridge. WSRT 21cm 1.9 Mpc radio lobes (Leahy).
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H 2 Shock-Excitation in 3C 326 ● H 2 Emission dominates cooling in C-type shocks (Le Bourlot 02) T(H 2 )=150-1000 K ● Magnetic (C-type) shock model: 2 velocities: v=4, 20 km/s ● n H =10 4 cm -3, B=100 G (Guillard 08, in prep)
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MOHEGs = H 2 Emission Galaxies ● Stephan's Quintet shock (Appleton et al. 06). ● Zw 3146 cool-core cluster cD (Egami et al. 06). ● SINGS AGNs (Roussel et al. 07) ● Radio Galaxies (Ogle et al. 07,08) L(H 2 )/L(IR)>2 10 -3 Infrared Luminosity
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Shocks vs. Star Formation ● H 2 and PAH dust occupy same ISM phase. ● Star forming galaxies have L(H 2 )/L(7.7 m PAH)~8 10 -3 ● Larger H 2 /PAH indicates shock heated H 2 in: -Radio galaxies (Ogle 08) -LINERs, Seyferts (Roussel 07) -Dusty ellipticals (Kaneda 08). (Ogle et al. 2008) Infrared Luminosity
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Shocks vs. AGN X-ray Heating ● AGN X-ray luminosities from Chandra (Evans 06; Hardcastle 06; Balmaverde 06; Ho 01) ● XDR maximum theoretical X-ray to H 2 conversion ~ 5% (Maloney 1996) ● Most of the AGN are not strong enough X-ray emitters to power the H 2. AGN X-ray Luminosity
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Radio Jet Mechanical Heating? ● Radio jet cavity powers are measured for 6/17 MOHEGs. (Rafferty 06; Bîrzan 04) ● P(jet cavity) = 4pV/t(bouyant) p,V, t estimated via Chandra. L(H 2 )/P(jet)=10 -4 -- 2 10 -3 Jet-driven H 2 outflow or fountain? (FWHM ~ 500 km/s seen in some sources.) H 2 cooling time ~10 4 yr. --Requires sustained heating Radio Jet Cavity Power
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Perseus A-- Multiphase ISM CO (2-1) HH M(cold H 2 )=4 10 10 M from CO (2-1) (Salome 06) M(4.0,0.6 keV)~(10 11,10 9 M ) (Chandra, Fabian 06) M(warm H 2 )>7 10 7 M (Johnstone 07) M(H II)= 3 10 7 M (Conselice 01) H2H2
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3C 293 Jet-Induced Outflow 1000 km/s H I and [O II] outflows (Morganti 03; Emonts 05). Possible jet/CO interaction. M(H 2 cold)=1.5 10 10 M (A. Evans et al. 1999) M(H 2 warm)=1 10 9 M (Ogle 2008) M(HI)=20 M /yr M(HI)=10 7 M M ion =0.1 M /yr..
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Rogues Gallery 3C 31 3C 338 3C 315 3C 3C 433 3C 436 3C 326 3C 310 3C 386 Credit: DRAGN Atlas
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Star Formation Rates ● MOHEG star formation rates are modest: 0.01-3 M /yr (from PAH inside 3.7” slit) Will add little to ~ 10 11 M stellar bulge in a Hubble time. ● SFR does not correlate with warm H 2 mass. ● H 2 depletion timescales: 3 10 7 --7 10 10 yr Ogle et al. 2008
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Star Formation Efficiency 3C 326 and 293 fall below Schmidt law for star formation in normal galaxies. 3C 326 SFR~0.1M /yr at R<3.1 kpc. Our PdB CO observations indicate (H 2 )>350 M /pc 2 Jets may suppress disk formation by driving H 2 outflows or fountains with large velocity dispersion and low volume filling factors. Kennicutt 1998 PdB ? 326 293
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Future Directions ● Spitzer IRS spectra of more radio galaxies with H I outflows. ● Spitzer spectra of compact (CSS/GPS) radio sources ● Spitzer spectral map of MRC 1138 (z=2) radio galaxy. ● VLT/SINFONI IFU spectral maps of near-IR rovibrational H 2 ● CO maps and cold H 2 masses, ’s with PdB interferometer. ALSO NEEDED: ● More AGN X-ray fluxes (Chandra) ● Jet power estimates for non-cavity radio sources. ● THEORY! How do jets gently heat 1 10 9 M of H 2 to 200 K?? COMING SOON:
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