Galaxy fertility: nature versus nurture

Transcription

1 Galaxy fertility: nature versus nurture the view from the local Universe Fertility = Propensity to form stars given stellar mass fertility = star formation rate stellar mass =ssfr I Zw 18 = fertile NGC 3379 = M105 = infertile 1

2 Happy independence day! 2

3 Do galaxy properties depend on single parameter? Internal stellar velocity dispersion Bernardi et al. 03; La Barbera et al. 14 (early-type galaxies) Stellar velocity dispersion in ETGs stellar mass (not dark matter halo) Mamon & Łokas 05a 3

4 Central galaxy properties = f(halo mass) observations semi-analytical simulation hydrodynamical simulation stellar mass Bluck+16 galaxy properties = f(σv) = f(mstars) = f(mhalo) abundance matching: N(>Mhalo) = N(>Mstars) Marinoni & Hudson 02 halo mass

5 Satellite galaxies: properties = complicated! (former centrals) observations semi-analytical simulation hydrodynamical simulation stellar mass Bluck+16 halo mass

6 Another parameter for central galaxies? Mass-orbit modeling of central galaxies traced by their satellites DM concentration Wojtak & Mamon 13 log stellar mass redder galaxies earlier star formation higher DM concentration earlier halo mass assembly star formation history (SFH) = f(halo mass AND halo assembly time) galaxy assembly bias age matching: N(>age halo) = N(>age stars) Hearin & Watson 13 Baade 44 Wechsler+02 6

7 Spatial correlation vs color (age) Galaxy 2-point correlation functions dp =[1+w p (r p )] d SDSS Legacy Survey Zehavi+11 Zehavi+11; see Davis & Geller 76 red galaxies more strongly clustered 7

8 Galaxy bimodality all color color Schawinski+14 (see Strateva+01) in color early-type late-type log stellar mass log ssfr = SFR/mstars passive Knobel+15 star forming ssfr = SFR/(stellar mass) = fertility log stellar mass in star formation rate (SFR) 8

9 Physical Processes 9

10 What makes galaxies fertile? presence of (cold) Molecular Gas Star formation in Giant Molecular Clouds open=global filled=local Kennicutt diagram SFR surface density SFR ~ (molecular mass) / 2.4 Gyr Bigiel+11 molecular surface density 10

11 Galaxy mergers SFR / SFR(t=0) Di Matteo induce starbursts 2.consume gas & rapidly quench SF time (Myr) 11

12 What else quenches the fertility? Internal processes: supernova explosions Dekel & Silk 86 jets from active galactic nuclei (powered by supermassive black holes) Silk & Rees 98 heat up OR mechanically remove (ram pressure) cold gas supply see Dashyan+17 (in revision) for analytical comparison of mechanical feedback in AGN vs SNe AGN feedback can be positive! Begeman & Cioffi 89; Rees 89; Gaibler+12; Bieri+15,16 12

13 What else quenches the fertility? External processes: Prevent gas from falling into galaxy: low mass: entropy (temperature) is too high high mass: infall is supersonic Rees 86 Birnboim & Dekel 03 independent of environment 13

14 Fertility quenching by nurture (environment) gas infall 14

15 Fertility quenching by nurture (environment) gas infall Cluster tides suppress infall Larson+80 Ram pressure from cluster gas suppresses: infall & possibly interstellar molecular clouds Gunn & Gott 72 15

16 Tidal Stripping for Elongated Orbits shell of tidal radius has zero energy neglect spin & resonances Mamon 00, astro-ph/ ; Tollet, Cattaneo, GM+17 more complicated schemes: Gnedin+95; D Onghia+10 velocity impulse singular isothermal profiles for galaxy & cluster v star a tide (R peri ) a tide = a GM(R) R 3 Rperi V peri r fraction of retained mass apple m galaxy (r) V peri V circ (R peri ) m vir galaxy orbit M cluster (R peri ) M vir cluster pericenter independent of mstars/mcluster! 16

17 Ram Pressure Stripping for Elongated Orbits ram pressure P = ICM (R) V 2 cos velocity impulse v P gas R peri V peri singular isothermal profiles for galaxy & cluster fraction of retained gas mass m gas (r) m vir gas apple Vcirc (R peri ) V peri " (Rperi ) V 2 peri h (R) V 2 (R)i orbit ~ (mstars/mgroup) 2/3 # m vir galaxy M vir cluster! 2/3 Mcluster (R peri ) M vir cluster orbit mass ratio pericenter see also McCarthy+08, Ruggiero & Lima Neto 16 17

18 Ram Pressure beats Tides (in removing gas)! log (fraction-gas-mass-retained-rps/fraction-total-massretained-ts) 1 Log M ret,rp /M ret,td Tides dominate pericenter / apocenter R p /R a Ram pressure dominates -2 typical orbit elongations Irina DVORKIN m gal /M cluster galaxy mass / cluster mass 18

19 Horizon-AGN Hydrodynamical simulation Vladan Markov (M2 student) r/rvir(t) extreme moderate log Mstars/Mgroup < < log Mstars/Mgroup < 3.5 log Mstars/Mgroup > 3.5 mgas cold /max ssfr orbital phase orbital phase orbital phase cold gas lost in single (several) orbit(s) for extreme (moderate) mass ratios ssfr drops in single (several) orbit(s) for extreme (moderate) mass ratios 19

20 Environmental quenching of fertility segregation 20

21 Segregation by nature high density peaks collapse 1st t ~ (G ρ) 1/2 early assembling halos: more concentrated Wechsler+02 primordial density field threshold for red galaxies total cluster galaxies assembly bias: early collapsing halos: old stars DM concentration Wojtak & Mamon 13 log stellar mass see Kaiser 84; Evrard+90 red galaxies more frequent in & near clusters galactic conformity to large distances? 21

22 Questions Are environmental trends = f(group finder)? Do our imperfect measures of environment blur/bias the environmental effects Is quenching fast OR slow? How far do environmental effects act on galaxy fertility? Is observed segregation caused by Nurture (environment) OR Nature (initial conditions)? 22

23 How do we measure environment? Global environment: group mass galaxies like MW = groups (w LMC/SMC, dwarf spheroidals )? Local environment: galaxy position in group (central, inner/outer satellite) Large-scale environment: filament/field group satellite galaxy cluster filament cluster central galaxy LEGEND field galaxy group/cluster 23

24 How to extract real-space groups from redshift-space data? real space GM, Biviano & Murante 10 +κ σv Moore, Frenk & White 93 redshift distortions vlos / v200 r max r vir = apple r 2 v v v κ σv ' cz = H0D + vpec redshift space Dlos / r200 = overdensity / critical density

25 Group finders incomplete list! for spectroscopic galaxy samples Frequentist Friends-of-Friends Voronoi Tessellation Dendrograms Huchra & Geller 82 Marinoni+02 Tully 87 Prior-based Matched Filter Yang MAGGIE Kepner+99 Yang, Mo, van den Bosch +05, 07 Duarte & Mamon 15 25

26 Friends of Friends (FoF) survey edge survey edge 26

27 Friends of Friends (FoF) transverse linking length line-of-sight linking length Dimensionless linking lengths in terms of mean nearest neighbor separation: b = LL/ n(z) 1/3 Optimal linking lengths (analytical + tests on mocks) b = 0.07 & b// = 1.1 Duarte & Mamon 14 27

28 Yang et al. s Halo-based Group Finder density in projected phase space g(r, v z )= NFW (R) exp surface density v 2 z 2 2 LOS > 10 c Univ H 0 R = projected radius v z = line-of-sight velocity Yang, Mo & van den Bosch 04; Yang+07 Domínguez Romero, García Lambas & Muriel 12 group masses (hence virial radii) from: FoF group luminosities (1st pass: M=300L) Halo Abundance Matching on group luminosity (next passes) Accurate group masses (global environment), BGG at center (local environment) weaknesses LOS velocity dispersion profile should be convex in log-log (not cst) LOS velocity distributions not Maxwellian (outer radial vel. anisotropy) ad hoc threshold for membership (10) imprecise correction for lum. incompleteness (for SDSS flux-limited sample) hard group assignment is unstable 28

29 MAGGIE: Duarte & Mamon 15 Models & Algorithms for Galaxy Groups, Interlopers & Environment probabilistic P (R, v z )= g halo (R, v z ) g halo (R, v z )+g ilop (R, v z ) interlopers halo interlopers more realistic ghalo from ΛCDM 3D model with anisotropic velocities NFW z z 3D tracer density z z 3D LOS velocity distrib. σr(r) from solving Jeans equation z β(r) from cosmo simulations = 1 σθ 2 /σr 2 = velocity anisotropy 29

30 P (R, v z )= g halo (R, v z ) g halo (R, v z )+g ilop (R, v z ) MAGGIE: interlopers Duarte & Mamon 15 z z DM particles in HD simulation: Borgani+04 SAM: Guo+11 Duarte & Mamon 15 Mamon, Biviano & Murante 10 30

31 MAGGIE: Mamon & Duarte 15 Models & Algorithms for Galaxy Groups, Interlopers & Environment group masses by Halo Abundance Matching on central galaxy luminosity or stellar mass (1st pass) on total group luminosity or stellar mass (next passes) groups extracted from D- & L-complete subsamples group properties = sums weighted by probabilities 31

32 Testing Group Finders 32

33 Tests on mocks: group fragmentation mocks: SDSS-like galaxy catalog with errors on luminosities (0.08 dex) & stellar masses (0.2 dex) matching extracted & true groups by most luminous (L) or massive in stars (M) member fraction of extracted groups = secondary fragments of true groups Duarte & Mamon 15 only unflagged groups Ntrue 3 & Nest 3 FoF-M (solid) FoF-L (dashed) Yang-M Yang-L MAGGIE-M MAGGIE-L FoF clusters: high probability of being secondary fragment!

34 Tests on mocks: group total mass accuracy only unflagged primary-fragment groups Ntrue 3 & Nest 3 Duarte & Mamon 15 log luminosity 1 2 flux limit log distance FoF-M (solid) FoF-L (dashed) Yang-M Yang-L MAGGIE-M MAGGIE-L FoF virial theorem masses biased low by dex, 0.3 dex at hi mass 34

35 Tests on mocks: group total mass accuracy only unflagged primary-fragment groups Ntrue 3 & Nest 3 Duarte & Mamon 15 log luminosity 1 2 flux limit log distance FoF-M (solid) FoF-L (dashed) Yang-M Yang-L MAGGIE-M MAGGIE-L FoF virial theorem masses biased low by dex, 0.3 dex at hi mass mass accuracy M = 13: 0.35 (FoF), 0.32 (Yang), 0.28 M = 14: (FoF), 0.23 (Yang), 0.20 (MAGGIE) 35

36 Observational diagnostics of fraction of fertile galaxies vs. environment 36

37 Effects of galaxy environment on red galaxy fraction over density (from distance to 5th nearest neighbor) effect of density effect of stellar mass in stars Peng+10 spectral types Weinmann+06 Peng+10: red fraction boosted at hi density (for lo Mstars) or hi Mstars (at lo density) Weinmann+06: passive fraction boosted at hi group mass (less by position) & for innermost satellites (even at hi Mstars!) 37

38 Fraction of infertile galaxies log R/rvir log R/rvir log Mhalo/M log Mstars/M Woo+13 see Weinmann+06; Peng+10; von der Linden+10 increases with halo, stellar mass, inner position in group (complicated!) 38

39 Environmental effects as a function of group finder in progress Diego STALDER former Doctoral student INPE 39

40 fraction of fertile galaxies in SDSS log ssfr (Gyr 1 ) Knobel+15 f blue (R) =f 1 R R + a blue log stellar mass (M ) ln fquenched 1 f quenched = a + b log R r vir " Mstars ec 1 c log Mstars fc # + d log M logistic regression (see Maria-Luiza Dantas talk) formula chosen after comparison of ones with Bayesian evidence

41 strong variation with stellar mass especially at low end fsf log stellar mass 41

42 group finders on SDSS quenching normalization radial trend sharpness of Mstars Stalder, GM & Trevisan in prep. FoF Yang MAGGIE trend of Mgroup hi-end trend of Mstars lo-end trend of Mstars ln fquenched 1 f quenched = a + b log R r vir " Mstars ec 1 c log Mstars fc # + d log M

43 group finders on SDSS quenching normalization radial trend sharpness of Mstars Stalder, GM & Trevisan in prep. FoF Yang MAGGIE trend of Mgroup hi-end trend of Mstars lo-end trend of Mstars FoF: weaker trend with group mass, less quenching 43

44 group finders on mock SAM Henriques+15 quenching normalization radial trend sharpness of Mstars FoF Yang MAGGIE Perfect Stalder, GM & Trevisan in prep. trend of Mgroup hi-end trend of Mstars lo-end trend of Mstars MAGGIE: correct normalization & radial trend; too weak lo-end trend with Mstars vs SDSS: similar parameters, except slightly powers of Mstars 44

45 Radial variations group mass fsf stellar mass R/rvir 45

46 When are galaxies quenched as they fall into groups & clusters? 46

47 fraction of recent starbursts fraction of recent starbursts Time for quenching star formation Mahajan, GM & Raychaudhury 11 orbital classes of galaxies of galaxies virialized infalling projected radius Mahajan+11 cluster cluster slow quenching! backsplash z=0 radial phase space of DM particles Mahajan+11 physical radius A=infall Galaxies only quenched when they reach virial radius on their way out Time to rvir outwards: Gyr from entry, Gyr from pericenter Tollet, Cattaneo, GM+17 47

48 Slow or fast quenching by environment? z=0 radial phase space of DM particles Haines+15 z=0 projected phase space of DM particles Haines Gyr after entry < 0.5 Gyr after pericenter Fast Quenching cells of z=0 projected phase space of DM particles Time to rvir outwards: Gyr from entry, Gyr from pericenter Slow Quenching Tollet, Cattaneo, GM+17 Oman & Hudson 16 4 Gyr from entry Slow fading then fast quenching Wetzel Gyr after entry in 2.5 rvir 0.75 Gyr after pericenter Fairly Fast Quenching 48

49 Slow quenching Peng+15 (Nature) 4 Gyr 49

50 How far does the environment act on galaxy fertility? in progress Marina TREVISAN Postdoc, IAP

51 How far does the environment act on galaxy fertility? log Mstars: log Mstars: log Mstars: fraction of spectral types log Mstars: log Mstars > 10.7 von der Linden+10 2 r200 for low mstars 10 r200 for high mstars distance from BCG / r200

52 Explanations for large-scale environmental effects processing in filaments? von der Linden+10 backsplash galaxies? primordial density field? (pre-)processing in groups below mass threshold? 52

53 Backsplash? backsplash z=0 radial phase space of DM particles infall Mahajan, GM+11 Backsplash galaxies: have crossed cluster at least once How far can they go? 2 to 2.5 r100 Balogh, Navarro & Morris 00 Mamon+04 Gill+05 8 r100: 50% of particles are bound require ~4.3 σv to escape that far (possible) sometimes out to 3-4 r100 Sales, Navarro+07 Ludlow, Navarro+09 time to reach 8 r Hubble times! possible if start at z=2! (t0/4) 53

54 Assigning galaxies to nearest group 54 von der Linden+10: d = s R r v v 2 (Yang+07): redshift space d = f ( b R r 200,c exp " v v 2 #) d = s R r v v surface density log (R / r vir ) vlos / vvir log (r 3D / r vir ) Yang z-space real space distances in redshift space from cosmological simulation Trevisan+ in prep.

55 Assigning galaxies to nearest group von der Linden+10: d = s R r v v 2 (Yang+07): d = f ( b R,c r 200 exp " v v 2 #) Yang von der Linden z-space surface density v /v redshift space d = s R r v v Trevisan+ in prep / which minimum group mass to assign galaxies? 55

56 1-halo density profile to 20 rvir Trevisan, GM & Stalder 17 number density real space Universe surface number density redshift space residuals residuals NFW to 13 rvir for optimal group assignment mass in real space NFW to 10 rvir for optimal group assignment mass in redshift space Gary Mamon (IAP), Galaxies far beyond the virial radius of groups and clusters: the role of nature in the fraction of fertile galaxies, 22 June 2017, RoE/IfA 56

57 NFW-optimal group assignment mass Trevisan, GM & Stalder 17 log Massign=12.3 for log Msample=13 57

58 Fraction of star forming galaxies with better galaxy assignment scheme log ssfr (Gyr 1 ) Knobel+15 log stellar mass (M ) 58

59 min group assignment log mass = 13 R90 where fsf(r90) = 0.9 fsf( ) field fraction & quenching radius = independent of group mass group mass log M group f SF stellar mass log M stars, gal = centrals fsf saturates at R 4 rvir R / r vir

60 min group assignment log mass = 12.3 group mass log M group fsf saturates at R 2 rvir (except for hi stellar mass) log M group f 600 SF f SF stellar mass log M stars, gal jump of fsf at 2.5 rvir (hi Mstars): lose quiescent small groups pre-processing in groups of mass 12.3 to 13! 600 = centrals R / r vir R / r vir

61 Conclusions Are environmental trends = f(group finder)? Yes to some extent: try different group finders Do our imperfect measures of environment blur/bias the environmental effects? Yes: compare to mocks Is quenching fast OR slow? Fast after merging or strong ram pressure (low Mstars/Mgroup) Slow after moderate ram pressure (high Mstars/Mgroup) How far does environment act on galaxy fertility? = f(group min assignment mass) up to 2.5 virial radii Observed segregation by: Nurture (environment) OR Nature (initial conditions)? Mainly nurture! 61