Morphological quenching

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Marianna Hutchinson
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1 Morphological quenching Increased stability for gas disks in early-type galaxies Marie Martig (MPIA) With : Frederic Bournaud, Avishai Dekel, Romain Teyssier Alison Crocker, Eric Emsellem, Tim Davis, Martin Bureau, Pierre- Alain Duc + ATLAS 3D

Gas and star formation in early-type galaxies 2 Bureau et al. Young et al. 2011 3D Figure 1.

2 Gas and star formation in early-type galaxies 2 Bureau et al. Young et al D Figure 1. Mosaic showing CO distributions (solid blue lines) overlaid on (colours and solid black lines) for selected samplesee galaxies. also: ADavis range et of al morph ATLAS 3D : volume limited sample of 26 local ETGs 22% detection rate in CO! 2. Molecular gas properties 2011a,b, 2013, Alatalo et al 2013

Gas and star formation in early-type galaxies 3 parison of previously

The one lier is ngc4578, for which the new catalog data use posure.

2011 s of growth or from two-dimensional image e 1 presents a comparison

sense that 3D ATLAS 3D : volume limited sample of 260 local ETGs 22%

Optical color-magnitude diagram for the Altas3D sample.

3 Gas and star formation in early-type galaxies 3 parison of previously published NUV magnitudes log GR6 data for the Atlas 3D sample. The one lier is ngc4578, for which the new catalog data use posure. Young et al s of growth or from two-dimensional image e 1 presents a comparison of the catalog the results of Donas et al. (2007), Gil de 7), Jeong et al. (2009), and Carter et al. may be a systematic offset on the order of nt galaxies (NUV 16), in the sense that 3D ATLAS 3D : volume limited sample of 260 local ETGs 22% detection rate in CO! Figure 2. Optical color-magnitude diagram for the Altas3D sample. CO detections are indicated in red circles and nondetections in black crosses; the sizes of the red circles indcate the value of M(H 2 ) scaled logarithmically as indicated in the legend. Contours underneath show the red sequence and the blue cloud as indicated by a

4 Gas disk stability against local collapse and star formation Stability results from a competition between: self-gravity velocity dispersion which inhibits the collapse differential rotation that shears gas clouds Toomre parameter for a thin rotating gas disk: Q g = κσ g πgσ g Stability criterion: Q g > 1 For a gas disk embedded in a stellar disk: an effective Toomre parameter (stars contribute to instability) 1 Q = 1 Q g + 1 Q s

5 Gas disk stability in elliptical galaxies Gas disk is stabilized when stars are in a spheroid instead of a disk: steeper potential well reduced disk self-gravity ETGs should have lower star formation efficiencies: morphological quenching (Martig et al. 2009)

6 Morphological quenching in a cosmo simulation Elliptical galaxy with a massive gas disk but inefficient SF and red colors (Martig et al. 2009) MQ phase

7 Lower SF efficiency in elliptical galaxies

8 A comparison with high resolution AMR simulations AMR code RAMSES, 5 pc maximal resolution, star formation, kinetic SN feedback (Martig, Crocker et al. 2013) Same gas disk embedded in spiral or elliptical galaxy M gas =7.5 x 10 8 Msun, f gas =1.3%!""#$%#&'"()*+',-./01,$#2'"()*+',-./01 SFR = 0.1 Msun/yr SFR = 2.5 Msun/yr

9 A comparison with high resolution AMR simulations AMR code RAMSES, 5 pc maximal resolution, star formation, kinetic SN feedback Same gas disk embedded in spiral or elliptical galaxy M gas =2.5 x 10 9 Msun, f gas =4.5%!""#$%#&'"()*+',-3/41,$#2'"()*+',-3/41 SFR = 4.8 Msun/yr SFR = 11.3 Msun/yr

10 The resulting Kennicutt relation

11 Resolved observations of molecular gas and star formation in ETGs Name Distance H 2 mass (Mpc) log(m ) NGC NGC NGC NGC NGC NGC NGC NGC CO maps : BIMA (Young et al. 2008) and PdBI (Crocker et al. 2009,2011) HI mass: Westerbork (Serra et al. 2012) SFR maps: non-stellar 8 m emission (Shapiro et al. 2010) +12 spirals with data from THINGS (Walter et al. 2008), BIMA-SONG (Helfer et al. 2003) and SINGS (Kennicutt et al. 2003) surveys

12 Observed ETGs have a lower star formation efficiency SF efficiency ~2 x lower (Martig, Crocker et al. 2013)

13 Also seen by the COLD GASS survey Saintonge et al 2012

14 Conclusion (1) Morphological quenching: gas disks are stabilized against star formation when embedded in a stellar spheroid instead of a disk Observational and numerical evidence for SF efficiency 2-5 times lower in ETGs Enough to make galaxies red Caveats: There is an upper limit to the amount of gas that can be stabilized Effect of mergers?

15 Conclusion (2) MQ could be in part why quenching and bulges are related (Bell et al. 2008, Lang et al. 2014,...) Would make life easier for other mechanisms: no need to totally shut off gas accretion/cooling BUT we need molecular gas observations to prove MQ is occurring ( ) ( ) WE DO NOT MAKE PREDICTIONS FOR THE GAS CONTENT OF ETGs!!! If the morphological quenching scenario is correct, then at fixed stellar mass, we would expect to find higher average Hi gas fractions for bulge-dominated galaxies on the red sequence than for disk-dominated galaxies on the red sequence. (Fabello et al 2011)

News from. the Atlas 3D project. Eric Emsellem

News from. the Atlas 3D project. Eric Emsellem News from the Atlas 3D project Eric Emsellem and the team U - B 10 Mpc Hierarchical Galaxy Formation Dark Matter Gas Density Gas T Stars The Mare Nostrum Simulation = Teyssier et al. Adapted from Faber