Feeding High-z Galaxies from the Cosmic Web

Transcription

1 Feeding High-z Galaxies from the Cosmic Web Avishai Dekel The Hebrew University of Jerusalem Jerusalem Winter School 2012/13 Lecture 1

2 z=0

3 z=2

4 z=8

5 Cosmological simulations Toy modeling Oxford Dictionary: simulate pretend to be, have or feel, hide under a false appearance, feign, put on, dissemble Consider a spherical cow

6 Toy modeling Cosmological simulations Consider a spherical cow Oxford Dictionary: simulate pretend to be have or feel, hide under a false appearance, feign, put on, dissemble

7 Key Concepts at high z 1. Cold Streams from Cosmic Web co-planar, pancakes, angular momentum, mergers, outflows, detection in Lyα 2. Violent Disk Instability (VDI) in-situ clumps, evolution of instability 3. Instability-Driven Inflow spheroids, black Holes

8 Lecture 1: Outline 1. Cosmological inflow rate 2. Virial shock heating and cold flows 3. Cold streams from the cosmic web 4. Smooth flows and mergers 5. Stream penetration and fragmentation 6. Observing cold streams in Lyman alpha 7. Angular momentum: transport and exchange 8. Outflows

9 1. Cosmological Inflow rate Neistein, van den Bosch, Dekel 2006 Neistein & Dekel 2008 Dekel et al. 2009; 2012 Genel et al. 2008

10 Accretion Rate into a Halo at z>1 1 EdS cosmology at z>1 a= (1+ z) Virial relations 2 3 V = GM R M ( 4R ) = 200 ρ 200 u ( t / t V 1 ) 2/3 ρ u t 1 = (2/3) Ω 3 = ρ0a ρ0 1/ 2 m H Gyr 30 gcm 3 1/3 1/ 2 1/ M12 (1+ z) 3 R100 M12 (1+ z) 3 From EPS and N-body simulations (5-10% accuracy) M& β µ 1 M sm (1+ z) s 0.03Gyr 0.14 ( n+ 3) / 6 µ 5/ 2 12 β PS self-invariant time EPS evolution of main progenitor M& M M 0 = M1+ M t1 t0 P ω=δ / D( a) D a t M c / ω = const. Toy model 5/ 2 1 P M& ( 0 2/3 n k & ω a M & M s (1+ z) s 0.03Gyr α ( z z0 ) M z) M e α = (3/ 2) st ( baryon M yr M12 (1 z) 3 5/ 2 M1 M 0) = f ( M1 M ) g( σ ( M )) M & 80 + f 0.17

11 AMR Cosmological Simulations Cosmological box, RAMSES (Teyssier), resolution 1 kpc Zoom-in individual galaxies, ART (Kravtsov, Klypin), RAMSES Ceverino, Tweed, Dekel, Primack: - 50 pc res. (30 galaxies) - 25 pc res., lower SFR, stronger feedback Isolated galaxies, resolution 1-10 pc, RAMSES, Bournaud et al. Collaborators: Bournaud, Teyssier, Krumholz, HUJI: Ceverino, Goerdt, Mandelker, Tweed, Zolotov, UCSC: Fumagalli, Moody, Mozena,

12 Toy Model vs Simulations Dekel, Zolotov, Tweed, Cacciato, Ceverino, Primack / 2 1 M & α ( z z0 ) M = s(1+ z) s= 0.03Gyr M ( z) M 0e α

13 Steady State: SFR Governed by Accretion Mass conservation M & τ, 1 acc M & gas = M& acc Kennicutt SFR If sfr vary on a timescale < τ sfr M gas = M& acc τ (1 e t / τ Steady state after τ sfr acc ) M& gas M & = M& acc M& e * M & = t / τ M * gas τ sfr f& M& = * a bf = M& acc (1 e gas 0 M * M acc Timescale for change of parameters from z=4 to z<1 M& 1 acc τ sfr t 4τ sfr dm& t 4τ 1 sfr / dt dτ / dt τ sfr t t ff t t ff disk t t disk vir t t vir sfr & ε t -1 ff ff & t / τ 0.75Gyr )

14 Cosmological Steady State: SFR ~ accretion rate into the disk Mass conservation: M & gas = M& gas,acc M& sfr M & = sfr M gas τ sfr M & sfr M& gas,acc M& gas 0 But gas accumulates in disks at earlier times and in smaller masses

15 Star-formation history: SFR = f b M& halo M min =2x10 10 Bouche et al

16 2. Virial shock heating and cold flows Rees & Ostriker 1977; Silk 1977; Binney 1977 Birnboim & Dekel 2003; Dekel & Birnboim 2006 Keres et al. 2005,2008; Ocvirk et al. 2008

17 3. Virial Shock Heating Birnboim & Dekel 03, Keres et al 05, Dekel & Birnboim 06 t 1 < t 1 cool compress - Critical halo mass ~10 12 M ʘ - Cold streams penetrate the.hot medium at z>2 Kravtsov

18 Old Standard Picture of Infall to a Disc Rees & Ostriker 77, Silk 77, White & Rees 78, Perturbed expansion Halo virialization Gas infall, shock heating at the virial radius Radiative cooling Accretion to disc if t cool <t ff Stars & feedback M<M cool ~ M

19 -21 Cooling rate ic [erg cm3 /s] -22 Z=0.05 Z=0 Z=0.3 log Λ mi -23 T -1 q = Line emission Bremsstrahlung A 2 2 N χ µ Λ( T ) ρ [erg g -1 s -1 ] N log T [K] A / µ molecules per g χ e - per particle

20 Cooling vs Free Fall Rees & Ostriker 77; Silk 77; White & Rees 78; Blumenthal et al T galaxies Brems. log gas density H 2 CDM t cool <t ff H upper bound too He big clusters virial velocity

21 Consider a spherical cow

22 Gas through shock: heats to virial temperature compression on a dynamical timescale versus radiative cooling timescale Shock-stability analysis: post-shock pressure vs. gravitational collapse t 1 < t 1 cool compress t compress 21ρ 5 & ρ 4 3 R V s

23 Shock Stability post-shock pressure vs. gravitational collapse adiabatic: γ = ln ln P ρ s stable: γ > 4 / 3 Birnboim & Dekel 03 with cooling rate q (internal energy e): γ eff d(lnp) d (lnρ ) ρ q = γ = & ρ e e& = PV& q 5 5 t 3 21 t comp cool t comp 21ρ Rshock 5 4 & ρ 3 V t e q T ρλ( T, Z) cool T V ρpost 4 ρ pre Stability criterion: γ eff 10 > 7 t 1 < t 1 cool compress

24 Growth of a Massive Galaxy T K M ʘ M ʘ shock-heated gas disc Spherical hydro simulation Birnboim & Dekel 03

25 A Less Massive Galaxy T K M ʘ cold infall shocked disc Spherical hydro simulation Birnboim & Dekel 03

26 Hydro Simulation: ~Massive M=3x10 11 M Kravtsov et al. z=4 M=3x10 11 M T vir =1.2x10 6 K R vir =34 kpc virial shock

27 Less Massive M=1.8x10 10 M Kravtsov et al. cold infall virial radius z=9 M=1.8x10 10 T vir =3.5x10 5 R vir =7 kpc

28 Shock-Heating Scale stable shock Birnboim & Dekel 03 Dekel & Birnboim 06 Keres et al 05 M vir [M ʘ ] 6x10 11 M ʘ typical halos unstable shock

29 The Critical Mass: Cosmological Simulations SPH Keres et al 2005, AMR Kravtsov et al M<<10 12 M ʘ cold flows M>10 12 M ʘ virial shock heating virial radius

30 Fraction of Cold Gas in Halos: Cosmological simulations (Kravtsov) cold hot Birnboim, Dekel, Neistein 2007

31 Virial shock: rapid expansion from the inner halo to R vir Necessary condition M>M crit Trigger: minor merger d(entropy)/dt

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34 Two Galaxy Types: Bi-modality

35 Bi-modality in color, SFR, bulge/disk 0.65<z< <z<0.75 E/S0/Sa /Sa Disks and Irregulars M *crit ~3x10 10 M ʘ Bell

36 Color-Magnitude bimodality & B/D depend on environment ~ halo mass environment density: low high very high disks spheroids SDSS: Hogg et al. 03 M halo <6x10 11 field M halo >6x10 11 cluster

37 Galaxy Bi-modality about M crit Dekel & Birnboim 06 While halos grow by smooth accretion and mergers M<M crit : The Blue Sequence cold gas supply disk growth & star formation Stellar feedback regulates SFR long duration mergers & disk instability bulges M>M crit : The Red Sequence shock-heated gas + AGN fdbk no new gas supply gas exhausted SFR shuts off passive stellar evolution red & dead further growth by gas-poor mergers

38 In a standard Semi Analytic Model (GalICS) z=0 data --- sam --- excess of big blue color not red enough Cattaneo, Dekel, Devriendt, Guiderdoni, Blaizot 06 no red sequence at z~1 too few galaxies at z~3 color u-r star formation at low z magnitude M r

39 With Shutdown Above M ʘ color u-r magnitude M r

40 Standard color u-r magnitude M r

41 With Shutdown Above M ʘ color u-r magnitude M r

42 From Blue to Red Sequence by Shutdown Dekel & Birnboim M vir [M ʘ ] hot M shock cold in hot all cold redshift z

43 3. Cold Streams from the Cosmic Web Dekel et al Danovich, Dekel, Hahn, Teyssier 2012 Pichon et al Kim et al. 2012

44 At High z, in Massive Halos: Cold Streams in Hot Halos in M>M shock Totally hot at z<1 shock Cold streams at z>2 Dekel & Birnboim 2006 Kravtsov et al cooling no shock

45 Mass Distribution of Halo Gas disk density cold flows adiabatic infall shockheated Temperature

46 Cold Streams in Big Galaxies at High z M vir [M ʘ ] all hot M shock ~M * cold filaments in hot medium M shock >>M * M shock all cold M * redshift z Dekel & Birnboim 06

47 high-sigma halos: fed by relatively thin, dense filaments cold narrow streams typical halos: reside in relatively thick filaments, fed ~spherically no cold streams the millenium cosmological simulation

48 Origin of dense filaments in hot halos (M M shock ) at high z At low z, M shock halos are typical: they reside in thicker filaments of comparable density M s ~M * At high z, M shock halos are high-σ peaks: they are fed by a few thinner filaments of higher density M s >>M * Large-scale filaments grow self-similarly with M * (t) and always have typical width ~R * M * 1/3

49 Narrow dense gas streams at high z versus spherical infall at low z high z low z M=10 12 M ʘ >>M PS M=10 12 M ʘ ~M PS Ocvirk, Pichon, Teyssier 08

50 Critical Mass and Cold Streams in Hot Halos: Cosmological Simulations Ocvirk, Pichon, Teyssier 08 M shock M stream DB06 cold filaments in hot medium

51 Cold Sterams at ~1 kpc Resolution - >90% of influx in cold streams - Penetration: V~V vir dm/dt(r)~const - Hot accretion negligible recycled outflows 100 kps Dekel et al 09 Nature

52 Cold streams through hot halos.

53 Cold streams through hot halos outflows

54 Flux per solid angle Dekel et al 09

55 Streams riding DM filaments of Cosmic Web. High-z massive galaxies form at the nodes.

56 Cosmic-web Streams feed galaxies: mergers and a smoother component AMR RAMSES Teyssier, Dekel box 300 kpc res 30 pc z = 5.0 to 2.5

57 Streams Feeding a Hi-z Galaxy Tweed, Dekel, Teyssier RAMSES Res. 50 pc

58 Streams Feeding a Hi-z Galaxy Ceverino, Dekel, Primack ART res pc

59 Cold Streams Penetrate through Hot Halos M v > M 100 kpc Agertz et al 09

60 Co-planar Streams and Pancakes 200 influx M yr -1 rad -2 Danovich, Dekel, Teyssier, Hahn R vir

61 Streams in a Pancake influx M yr -1 rad -2

62 Streams in a Pancake

63 Flows into pancakes, and along pancakes to filaments The stream plane extends from r<0.4rv to r>5rv Influx at R vir : 70% in streams, 20% in pancakes Influx in the streams: 55% in 1 stream, 90% in 3 streams MW4 z=7 influx M yr -1 rad -2 MW4 z=2.3

64 Distribution of Influx in Streams and Pancakes Influx: 70% in streams 20% in pancakes streams pancakes >50% in 1 stream >90% in 3 streams

65 Origin of Structure near a Node of the Cosmic Web A dominant filament in a dominant sheet within a smoothing volume 3 major filaments in a plane (Arnold et al. 1982) A honeycomb: maximum volume of voids minimum length of filaments

66 Entropy Pancakes of low Entropy Influx Hahn MW MW4 MW5

67 4. Smooth Flows and Mergers Dekel et al. 2009

68 Stream Clumpiness - Mergers Dekel, Teyssier et al 09; MareNostrum RAMSES sims 1kpc res Mass input to galaxies (all along streams) - Major mergers >1:3 <10% - Major+minor mergers >1:10 ~33% - Miniminors and smooth flows ~67% M=10 12 M ʘ z=2.5

69 Distribution of gas inflow rate Cosmological hydro simulations (MareNostrum, Dekel et al. 09) P ( M & M ) smooth flows mergers >1:10

70 Galaxy density at a given gas inflow rate Dekel et al. 2009, Mare Nostrum Simulation SFR ~(1/2) inflow rate M & 2M & * Star-Forming Gal s Sub-Millimeter Gal s SFR~

71 Mergers have a Limited Contribution to SFR At a given dm/dt, 3/4 galaxies are fed by smooth flows SFGs are miniminor mergers, i.e. smooth flows Bright SMGs are mergers & smooth flows

72 In-situ vs Ex-situ Star Formation ex-situ Tweed, Zolotov, Dekel, Ceverino et al in disk in bulge From z=4 to z=1 In-situ SFR 77%-57% Ex-situ mergers 23%-43%

73 Mass Added in Major vs Minor Mergers Neistein & Dekel 2008 ω = δ c D (t) ( dm dω ) M minor M & ( dm dω = ) ω & M M ω& 0.04 (1+ z) 2.5 Gyr 1 major

74 5. Stream penetration and fragmentation Dekel et al Dekel, Zolotov, Tweed, Ceverino, Primack 2013

75 Baryon Penetration to the Disk: ~50% Toy models versus simulations (ART 50 pc): Dekel, Zolotov, Tweed, Cacciato, Ceverino, Primack R vir EPS approximation: M & = Gyr M (1 z M= M e 0 ) 0.8( z 5/2 z 0 ) 0.1 R vir A proxy for SFR

76 Baryon Penetration to the Disk: ~50% Toy models versus simulations (ART 50 pc): Dekel, Zolotov, Tweed, Cacciato, Ceverino, Primack EPS approximation: M & = Gyr M (1 z ) 5/2 R vir M = M e 0 0.8( z z 0 ) 0.1 R vir A proxy for SFR

77 Streams Break Up - the Messy Region Ceverino, Dekel, Bournaud, Primack ART 35-70pc resolution streams disk interaction region Higher resolution reveals smaller clumps: - Merging galaxies with DM halos - Baryonic clumps hydro and thermal instabilities

78 Supersonic cold stream in a hot medium (2D) Burkert, Ntormousi, Forbes, Dekel, Birnboim

79 Supersonic cold stream in a hot medium (2D) Burkert, Ntormousi, Forbes, Dekel, Birnboim

80 6. Observing Cold Streams in Lyman alpha Emission: Goerdt et al. 2010, Kasen et al Absorption: Fumagalli et al. 2011, Goerdt et al ART code (Klypin, Kravtsov) Simulations: Ceverino, Dekel, Bournaud 2010

81 Lyman-alpha Emission (LA Blobs) Radiative transport of UV & Lyα, fluorescence from stars, dust Goerdt et al. 10; Kasen, Ceverino, Fumagalli, Dekel, Prochaska, Primack z=4.5 M v ~10 12 M L~10 43 erg s -1 d~100 kpc 100 kpc 100 kpc Extended source of cold H is provided by the inflowing (clumpy) streams Energy is provided by: z= inflow down the gravitational..potential Mv~10 12 M gradient 2. fluorescence L~10 43 erg s -1 by stars d~100 kpc Yet to be incorporated: AGN, enhanced outflows

82 Gravity Powers Lyman-alpha Emission E heat (r)= f c M φ r & c Eheat ergs fc M12 (1+ z) 4 In AMR simulations: V inflow ~V vir ~const. potential gain dissipates to L α Half the luminosity outside 0.3R v LABs from galaxies at z=2-4 are inevitable Have cold streams been detected? Gravitational heating is generic (e.g. clusters)

83 Lyman-alpha from Cold streams Fardal et al 01; Furlanetto et al 05; Dijkstra & Loeb 09 Goerdt, Dekel, Sternberg, Ceverino, Teyssier, Primack 09 T=(1-5)x10 4 K n= cm -3 N HI ~10 20 cm -2 pressure equilib. Surface brightness L ~ erg s kpc

84 Cold streams as Lyman-alpha Blobs 100 kpc Goerdt, Dekel, Sternberg, Ceverino, Teyssier, Primack 09 Matsuda et al 06-09

85 Lyman-alpha Luminosity Function Matsuda et al 09 Isophotal area and kinematics also consistent with data

86 Detection of Inflow in Lya Emission Kulas, Shapley et al Systemic z from Hα Most are red-shifted -> outflows 5% are blue-shifted -> inflow Kasen et al. 12

87 Cold Streams as Absorption Systems Fumagalli, Prochaska, Kasen, Dekel, Ceverino, Primack 2011; Goerdt et al MFP cm -2 LLS cm -2 DLA >20.3cm -2 SLLS cm -2

88 HI Absorption Systems Fumagalli, Prochaska, Kasen, Dekel, Ceverino, Primack 11 9% 500 average line profile DLA neutral, thick SLLS ionized-neutral Stacked absorption line profile is weak because of low sky coverage Inflow signal consistent with MFP observatios (Steidel et LLSal. 10) SLLS LLS ionized, HI thick Inflow undetectable in metals because of low Z and coverage MFP thin-thick DLA

89 Lya Image radiative transfer Kasen et al 11: including Lya multiple scattering, UV bkgd, Fluorescence from stars

90 7. Angular Momentum: Transport and Exchange Danovich et al Pichon et al. 2012; Kim et al. 2012

91 In-streaming Extended Rotating Disk - AM by transverse motion of streams impact parameter - Streams transport AM into the inner halo - One stream is dominant - Higher J/M at later times inside-out disk buildup 100 kpc Agertz et al 09

92 Disk AM Buildup by Streams

93 AM Exchange in the Inner Halo AM disk AM(r) Danovich, Dekel, Hahn, Teyssier 2012 Pichon et al. 2012; Kim et al Is AM amplitude conserved to within a factor of 2? streams AM is not conserved all the way to the disk! Torques & AM exchange in the inner halo ~0.3R v disk interaction region Ceverino, Dekel, Bournaud 2010 ART 50 pc resolution

94 Angular Momentum on Halo Scale AM StrPln Only little alignment between stream plane and AM at R v Most of the AM in one stream

95 Disk is not aligned with AM at r>0.3r vir AM disk AM Rv AM disk AM(r) AM Rv AM(r)

96 8. Outflows

97 Theory Challenge: Inflow and Outflow - What drives the massive outflows in massive galaxies? How do the outflows affect the inflows? Need to maintain Inflow + Reservoir = SFR + Outflow

98 Inflows & Outflows Tweed, Dekel, Teyssier RAMSES 70-pc resolution Outflows find their way out through the dilute medium no noticeable effect on the dense cold rapid inflows dilute hot high Z Gas density Temperature Metallicity

99 Inflows and Outflows House, Tweed, Ceverino et al. outflow η~0.7 in-streaming ~1.7SFR

100 Conclusions Certain robust predictions for high-z galaxies in λcdm cosmology - Cosmological inflow rate Mdot/M ~ 0.03 Gyr -1 (1+z) 2.5 M α exp(-0.8z) - Steady state: SFR ~ accretion rate, M gas ~const., as long as τ sfr ~ ε -1 t ff - Shock heating scale M v ~10 12 M - cold flows / hot medium - bimodality - High-z massive galaxies fed by cosmic-web streams, smooth & mergers - ~3 co-planar streams (70%) in a pancake (20%) - ~50% penetration into the galaxy; instabilities, messy region near disk - Streams (mostly one) transport AM. AM exchange in the inner halo. - Cold streams are observable in Lya emission (LAB) and absorption (LLS) - Outflows are in harmony with the in-streams (tentative)

101 Cosmic Web, Cold Streams, Clumpy Disks & Spheroids 50 Mpc 100 kpc 100 kpc stars 5 kpc 5 kpc

102