The Blessing and Curse of Cold Flows

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The Blessing and Curse of Cold Flows
Avishai Dekel
The Hebrew University of Jerusalem
UC Irvine, April 2008
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Outline
1. Cold flows vs virial shock heating
....Critical halo mass
galaxy bimodality 2. Cold streams in hot massive
halos .Big blue
disk galaxies at high z 3. Warm streams in very
massive halos
.Quenching clusters and ellipticals
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1. Cold Flows vs Virial Shock Heating Critical
Halo Mass Galaxy Bimodality
Birnboim Dekel 2003 Dekel Birnboim 2006
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Classic Picture of Disk Formation
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 tcoollttff
Stars feedback
MltMcool 1012-13M?
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Consider a spherical cow
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Gas through shock heats to virial temperature
compression on a dynamical timescale versus
radiative cooling timescale
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Growth of a Massive Galaxy
T K
1012M?
1011M?
shock-heated gas
disc
Spherical hydro simulation Birnboim
Dekel 03
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A Less Massive Galaxy
T K
1011M?
shocked
cold infall
disc
Spherical hydro simulation Birnboim
Dekel 03
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The Critical Mass Cosmological Simulations
SPH Keres et al 2005, AMR Kravtsov et al
Mgt1012M? virial shock heating
Mltlt1012M? cold flows
virial radius
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Formation of a virial shock at the critical mass
rapid expansion from the inner halo to the
virial radius
Entropy gradient
Libeskind, Dekel, Birnboim
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Shock-Heating Scale
Dekel Birnboim 06
stable shock
Mvir M?
6x1011 M?
typical halos
unstable shock
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Fraction of Cold Gas in Halos Cosmological
simulations
cold
hot
Birnboim, Dekel, Neistein 2007
Zinger, Birnboim, Dekel, Kravtsov
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Fraction of cold inward flux at
0.2RvirCosmological Simulations
Ocvirk, Pichon, Teyssier 08
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Two Key Processes
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From blue sequence to red sequence Dekel
Birnboim 06
1014 1013 1012 1011 1010 109
cold
hot
in hot
Mvir M?
Mshock
all cold
0 1 2 3 4 5
redshift z
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Bi-modality in color, SFR, bulge/disk
0.65ltzlt0.75
E/S0/Sa
Disks and Irregulars
Bell
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Color-Magnitude bimodality B/D depend on
environment halo mass
environment density low high
very high
disks
spheroids
Mhalolt6x1011 field
Mhalogt6x1011 cluster
SDSS Hogg et al. 03
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In a standard Semi Analytic Model (GalICS)
Cattaneo, Dekel, Devriendt, Guiderdoni, Blaizot 06
color
color u-r
magnitude Mr
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With Shutdown Above 1012 M?
color u-r
magnitude Mr
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Standard
color u-r
magnitude Mr
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With Shutdown Above 1012 M?
color u-r
magnitude Mr
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2. Cold Streams in a Hot Medium Big Blue
Disk Galaxies at High z
Massive starbursts without major mergers?
Dekel Birnboim 2006 Birnboim, Dekel Neistein
2007
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Shocked Accretion cold flows and quenching
Birnboim, Dekel, Neistein 07
1013
disk accretion rate
0 2 4 6
8 10 12
High SFR at hi z in M1011M? galaxies Suppressed
SFR in half the galaxies Galaxies can switch
blue-red-blue-
time Gyr
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Shocked-Accretion Massive Burst And Shutdown
SAMBA
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SAM Massive Starbursts at high z
Mhalo
SFR
mergers
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At High z, in Massive Halos Cold Streams in a
Hot Medium
in MgtMshock
Totally hot at zlt1
Cold streams at zgt2
cooling
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Mass Distribution of Halo Gas
density
Temperature
Analysis of Eulerian hydro simulations by
Birnboim, Zinger, Dekel, Kravtsov
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Cold, dense filaments and clumps (50)riding on
dark-matter filaments and sub-halos
Birnboim, Zinger, Dekel, Kravtsov
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Massive High-z Disks by cold flows
200 M? yr-1
Ocvirk, Pichon, Teyssier 08 - AMR res 2kpc
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Cold flows riding dark-matter filaments
gas density
gas temperature
dark matter
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Cold Streams in Big Galaxies at High z
1014 1013 1012 1011 1010 109
all hot
Mvir M?
Mshock
all cold
0 1 2 3 4
5
redshift z
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high-sigma halos fed by relatively thin, dense
filaments ? cold flows
typical halos reside in relatively thick
filaments, fed spherically ? no cold flows
the millenium cosmological simulation
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Origin of dense filaments in hot halos
(MMshock)at high z
At low z, Mshock halos are typical they reside
in thicker filaments of comparable density
MsM
At high z, Mshock halos are high-s peaks they
are fed by a few thinner filaments of higher
density
MsgtgtM
Large-scale filaments grow self-similarly with
M(t) and always have typical width R ?M1/3
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Dark-matter inflow in a shell 1-3Rvir
Seleson Dekel
density
temperature
radial velocity
MM
MgtgtM
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Cold Streams in Big Galaxies at High z
1014 1013 1012 1011 1010 109
all hot
Mvir M?
Mshock
all cold
0 1 2 3 4
5
redshift z
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Gas Density in Massive Halos 2x1012M?
high z
low z
M1012M?
M1012M?
Ocvirk, Pichon, Teyssier 08
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Temperature in Massive Halos 2x1012M?
high z
low z
Ocvirk, Pichon, Teyssier 08
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Flux Weighted Temperature Distribution
Ocvirk, Pichon, Teyssier 08
Halo Mass ?
hi z
cold
hot
cold
low z
cold
hot
4 5 6 7
4 5 6 7 4
5 6 7
log T log T
log T
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Cold Fraction of Inward Flux
zgt3
zlt3
Ocvirk, Pichon, Teyssier 08
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Critical Mass in Cosmological Simulations
Ocvirk, Pichon, Teyssier 08
Mstream
DB06
Mshock
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Observed Maximum Bursts
Genzel et al. 2006,
- Optical/UV-selected galaxies at z2-2.5 -
Mstar1011M? SFR 200 M? yr-1 - Most
of the mass is bursting -gt gaseous input - Very
rapid SFR burst 0.5 Gyr
...tSFR lt Rvir/Vvir tcool ltlt tHubble
- Disk morphology kinematics no major mergers
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Maximum Burst BzK-15507 (Genzel et al 2006)
z2.4
Mstar0.8x1011M? Mgas0.4x1011M? SFR150 M?
yr-1 ?t0.5 Gyr
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Rotation curves to Rgt10 kpc
CDFS K20-5
ltr1/2gt3.7(1.6) kpc, ltvcgt180(90) km/s,
Mdyn0.5-25x1010 M?
Förster Schreiber et al. 2006, ApJ 645,
1062 Genzel et al. 2006, Nature, Aug 17th
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LIRGS at z0.7 High SFR in Massive Rotating
Disks Hammer et al 2004
180 km/s
-180 km/s
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Disk Formation by Cold Flows at high z
Cosmological accretion rate (Neistein Dekel 06)
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3. Warm Streams in Very Massive Halos Quenching
Clusters and Ellipticals
Shutdown without AGNs?
Birnboin, Dekel Neistein 2007 Dekel Birnboim
2008 Zinger, Dekel, Birnboim, Kravtsov,
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Virial shock heating - the trigger for quenching
Birnboim Dekel 03, Binney 04, Dekel Birnboim
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Natural critical halo mass at 1012M? No shutdown
at zgt2 due to cold streams A hot-dilute medium
is required for the coupling of.any feedback
source to the gas (gravitational heating, AGN)
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Once the halo gas is shock heated, what keeps it
hot?
Supernova feedback?? Not in
Mhalogt1012M? AGN feedback?
Regulated radio mode? Shocked Accretion?
Mhalo 1012-1013M? Gravitational
heating by streams/clumps? Mgt1013M?
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Quenching by Shocked Accretion M1012-13 M?
cold flow
quenching
virial baryonic mass
3D simulations by Naab et al 07
quenching
disk accretion rate
0 2 4 6
8 10 12
time Gyr
Birnboim, Dekel, Neistein 07
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Gravitational Heating
Dekel Birnboim 2008
entropy, massive halo
density cold flows only
Baryons flow to the bottom of halo potential well
heating rate gt cooling rate
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Energy budget grav. accretion vs cooling
Tgas106-8
Neistein Dekel 07
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Global energy budget gravity vs cooling
H/C more efficient at high z
Mmin6x1012M?
Heat/Cool1
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Formation of a Massive Halo at Late z
AMR cosmological simulations of clusters (3 kpc
res.) Kravtsov, Nagai
entropy
z1
z0
filament/pancake shock
turbulence
stream
preheated -warm
stream
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Formation of a Massive Halo at Late z
AMR cosmological simulations of clusters (5 kpc
res.) Kravtsov, Nagai
density
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Penetrating Streams generating turbulence
Norman Bryan 1998
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Penetrating Streams Generate Turbulence
Zinger, Engel, Mumcuoglu, Dekel
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Penetrating Streams Generate Turbulence
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Penetrating Streams Generate Turbulence
Zinger, Engel, Mumcuoglu, Dekel
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Mass Flux Inward streams halt in core
virial shock
dM/dt M? yr-1
-104 M? yr-1
stable core hot flows
inflowing streams
0.01 0.1
1
r/Rvir
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Three Zones in a Cluster
virial shock r 2R200
inflowing streams
stable core r lt 0.2R200 turbulence hot flows
Zinger, Dekel, Kravtsov
Entropy
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Radial Flux dm/dt per rad2 relative to virial
flux
virial radius
shocked medium
preheated streams
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0.2Rvir
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0.2Rvir
10xFvir
extreme penetration massive streams dominate the
core
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supersonic hot streams
M3
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M3
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A more typical cluster
massive streams penetrate to 0.1 Rv
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In the rlt0.1Rv core some radial streams,
turbulence rotation
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A relaxed cluster
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Relaxed cluster weak penetration of streams into
rlt0.1Rv. They generate turbulence/rotation. Cold
cusp, but only inside rlt10kpc
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Unrelaxed cluster deep penetration of streams
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Unrelaxed clusters streams penetrate to the
rlt0.1Rv core and perturb the formation of a cold
cusp.
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Forces on a Shell (generalized Jeans eq.)
gravity thermal turbulence
hydrostatic equilibrium
total pressure/gravity
turbulence supports the core
thermal/gravity
turbulence/gravity
several clusters stacked together
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Gravitational Heating by Clumpy Accretion
Dekel Birnboim 2008 Khochfar Ostriker 2008
Gravitational accretion rate gt cooling rate for
Mhalo gt 6x1012M? Clumpy cold gas accretion into a
hot medium heating by
ram-pressure drag and local shocks 105-8M? gas
clumps penetrate to center and heat the gas
everywhere
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Mass Range for Effective Quenching
Dekel Birnboim 07
Mhalo gt 6x1012 M?
105 lt mclump lt 108 M?

• Origin of clumps?
• in DM subhalos?
• -thermal instability?

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Conclusions
- Cold flows build blue disks in halos Mhalolt
1012M?
- At high z, cold streams penetrate hot massive
halos, feed disks of M 1011M? with SFR 200
M? yr-1
- At lower z, quenching is initiated by virial
shock heating in Mhalogt1012M? (may be provoked
by mergers) ? red galaxies

• Long shutdown by shocked accretion in 1012 lt
  Mhalo lt 1013M?

• Long-term heating by gravitational energy of gas
  inflow into the inner hot halo. Heating gt
  Cooling in Mhalo gt 1013M?

- Pre-heated streams generate a turbulent core
(10-50) 0.1 Rvir Penetrating hot streams
minimize the cold cusp lt 0.01 Rvir
- Heating by drag/shocks of cold clumps 105lt
mclump lt108 M?
- AGN feedback needed only in the very central
regions
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Thank you
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The Blessing and Curse of Gas Accretion
As a function of halo Mass and redshift - Cold
flows ? disk star formation high z or M lt
1012 M? - Trigger of quenching virial shock
heating M 1012 - Maintenance I shocked
accretion 1012 lt M lt 1013 - Maintenance
II gravitational heating M gt 1013
streams?
clumps?