AGN fueling and feedback Franoise Combes Observatoire de Paris 1 - - PowerPoint PPT Presentation

Françoise Combes Observatoire de Paris Seoul, October 2013

Star formation, AGN fueling and feedback

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M82 N1433

Outline

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1- Gas distribution and Star Formation Star formation law is a molecular gas law 2- Star formation modes; main sequence, Starburst, mergers? 3- Modes of Quenching: SF and AGN feedback

M51, CO IRAM-PdB Schinnerer et al 2013

Atomic hydrogen HI-21cm

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Molecular gas from CO(2-1)

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Leroy et al 2013

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Molecular gas and Star formation

Bigiel et al 2009 H2 forms stars at a constant efficiency (n=1) Time-scale for SF 2 109 yrs At sub-kpc scale SFR not strongly Correlated with HI H2 when > 9 Mopc-2 Sgas SSFR

Essential role of H2

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Bigiel et al 2008 Average over 7 galaxies Confirmed with 38 galaxies, Heracles, Things Leroy et al 2013 SH2 SHI SSFR SSFR

Even in low surface density

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Schruba et al 2011

Disk simulations with H2/HI

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100 Myr -- afb= 40% c x 500 UV factor Halle & Combes 2013 afb energy fraction for SN feedback c UV radiation field H2 formation enhances the SFR Then the feedback expels gas  Thicker gas disk

Disk simulations with H2/HI

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Halle & Combes 2013

Star formation with H2

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Halle & Combes 2013 Without H2 With H2, afb=1%

Evidence of molecular thick disk ?

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50% of diffuse gas, M51, Pety et al 2013 More direct in edge-on galaxies, like NGC891, Garcia-Burillo et al 1992

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Depletion time lower towards the center

The star formation efficiency is larger in the galaxy centers Leroy et al 2013

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The depletion time is lower at high redshift

Daddi et al 2010, Genzel et al 2010 Galaxy centers are more starbursting Even in main-sequence galaxies SF time-scale shorter not only in starburst

2- Star formation modes: main sequence, starburst ?

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Bouwens et al 2012 HUDF + CLASH sSFR Specific SFR/M Inverse of growth time Change of the SSFR?

Main sequence, Major mergers

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Kaviraj et al 2013 80 Galaxies, z=2 M*> 1010Mo During mergers, still gas accretion May be 15% due to mergers? Wuyts et al 2011

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PHIBSS: 52 galaxies

Tacconi et al 2010, 2013 Molecular gas at IRAM, at z~2.3 and at z~1.2 High detection rate >85%, in these « normal » massive Star Forming Galaxies (SFG) Quiescent SF, in the main sequence Gas content ~34% and 44% in average at z=1.2 and 2.3 resp. SFR proportional to M*

0.8 (1+z)2.7

300 km/s 0.5”

1” (8.46 kpc)

log I – log V CO 3-2 - log I – log V log I - CO red – CO blue

EGS13003805 CO 3-2 velocity offset (km/s)

• 1000
• 500

500 1000

line intensity (mJy)

• 1

1 2 3 4

EGS13003805 z=1.23 CO: vc=250 km/s (i~570), R1/2=3.3 kpc (Rd(I)= 6.3), fgas=0.46

Evolution of specific SFR

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tdep=1.5/(1+z) Gyr Comparison with COLDGASS at z=0 Green: optical surveys

Starbursts 0.2 < z < 1

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Star formation efficiency and gas fraction sSFR=SFExMg/M* <z=1>/<z=0> 2.1 and 3.8 (with upper limits) 3.2 and 2.5 Both contribute, factor 3+1 increase between z=0 and 1 SF efficiency should also be increased due to more violent dynamics Combes et al 2013 SFR/Mgas Mgas/M*

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3- SF & AGN feedback

Salome et al 2008 Cooling flow clusters: Inflow and outflow coexist The cooled gas fuels the AGN The molecular gas coming from previous cooling is dragged out by the AGN feedback Ferruglio et al 2010

Mrk 231, SF and AGN

AGN and also nuclear starburst, 700 Mo/yr, >> ionised gas Perseus A

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Dasyra & Combes 2011, 2012 4C12.50 SFR ~400-1000 Mo/yr Outflow ~130 Mo/yr 6 out of 300 systems searched show H2 outflows

Feedback in nuclei: H2 & CO

Molecular outflows are massive

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N1377

Aalto et al 2012

Some outflows are more massive then their dense nuclear disk, e.g. N1377 200pc extent with modest 140km/s Mout= 1-5 107Mo, disk mass ~2 107 Mo Outflows due to SN: M82, Mout ~ 5107Mo V~200km/s (Nakai et al 1987) N3256 merger, Mout ~ 107Mo 10 Mo/yr, V~420km/s (Sakamoto et al 2006) Arp220, Pcygni profiles 100pc, HCO+, Mout ~ 108Mo (Sakamoto et al 2009) More violent outflows due to AGN: V> 1000km/s, up to 1200 Mo/yr OH, H2O abs Herschel, Sturm et al (2011), ULIRG+AGN Mrk231 (Feruglio+ 2010) 700 Mo/yr, depleted in 107 yrs, Mout ~ 108Mo N1266 (Alatalo et al 2011) Mout ~ 2 107Mo, depleted in ~108 yrs

Fueling in low-luminosity AGN

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NGC 1433: barred spiral, the « Lord of the Rings » Buta et al 2001 Atomic gas only in the inner and outer ring (Ryder et al 1996) CO in the nuclear ring and disk (Bajaja et al 1995) CO(3-2) with ALMA (Cycle 0) CO does not follow the nuclear bar

The Seyfert 2 NGC 1433

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CO(3-2) map with ALMA, No HCN, HCO+(4-3) Beam = 0.5’’ = 24pc Discovery of an inner ILR at r=200pc + Molecular torus? 24pc size, dust cont. Combes et al 2013

The smallest molecular outflow

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PV major axis PV minor axis CO on HST CO on unsharp masked HST image Flow of 50pc size

Properties of the outflow

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Total MH2= 5.2 107 Mo in FOV=18’’ MH2= 1.8 108 Mo in beam 43’’ (Bajaja et al 1995) Blue and red-shifted outflows, with 100km/s (200km/s if in the plane) 2’’=50pc from the center, Total 7% of the mass= 3.6 106 Mo SFR = 0.2 Mo/yr dM/dt ∼ (Mv/d) tanα= 7 tanα M⊙/yr,  ~40 SFR α = angle of outflow/line of sight Lkin=0.5 dM/dt v2 =2.3 tanα (1+ tan2α) 1040 erg/s Lbol (AGN)= 1.3 1043 erg/s Flow momentum >> LAGN/c  Jet driven flow, Pjet = 2 1042 erg/s from radio

Other low-luminosity AGN flows

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Driven by both the starburst and the radio jets The LINER NGC 6764: 4.3106 M⊙ Vout~100 km/s (Leon et al. 2007) Larger than in NGC 1433, but outflow rate ~1 M⊙/yr The LINER NGC 1266 highest flow rate of 13 M⊙/yr, with 2.4 107 M⊙ of H2 and V=177 km/s (Alatalo et al. 2011) LINER NGC1377, SFR of ∼ 1 M⊙/yr, outflow rate of 8 M⊙/yr, Mflow = 1.1 107 M⊙ at V=140 km/s (Aalto et al. 2012)

CONCLUSION

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 Star formation law is a molecular gas law  Depletion time scale lower in galaxy centers, as at high z  Stars form essentially on the MS (starburst small contribution)  Evidence of inflow/outflow: quenching by SN, powerful AGN  Low-luminosity AGN can drive molecular gas outflows