Bi-modality and Do w n s i z i n g Avishai Dekel HU Jerusalem Bernard ’ s Cosmic Stories, Valencia, June 2006 Origin of E vs S Galaxies

A third type of Bernard ’ s students: Those who were inspired by Jones ’ 1976 review

Origin of Bi-modality and Do w n s i z i n g Avishai Dekel HU Jerusalem Bernard ’ s Cosmic Stories, Valencia, June 2006

Summary Q: z<2: Bright, red & dead, E ’ s. No big blues. ………….Bi-modality, environment dependence A: Shutdown in M halo >10 12 Q: z~2-4: Massive, high-SFR disks(?) A: Cold flows (+mergers) even in M halo ~10 12 Trigger: virial shock heating (threshold mass) … …..Maintenance: “ AGN feedback ” (?) Q: From the blue to the red sequence A2: Feedback in M halo A: Two tracks: early/late shutdown, wet/dry mergers A1: Not anti-hierarchical for DM halos ! Q: Downsizing? Birnboim & Dekel 03 Dekel & Birnboim 06 Cattaneo, Dekel et al. 06 Neistein, van den Bosch & Dekel 06 Cattaneo, Dekel, Faber 06 Dekel et al. 05; Dekel & Cox 06 Seleson & Dekel 06

Summary Q: z<2: Bright, red & dead, E ’ s. No big blues. ………….Bi-modality, environment dependence A: Shutdown in M halo >10 12 Q: z~2-4: Massive, high-SFR disks(?) A: Cold flows even in M halo ~10 12 Trigger: virial shock heating (threshold mass) … …..Maintenance: AGN feedback Q: Origin of the tilted Fundamental Plane? A2: Shutdown in Mhalo >10 12 & feedback in M halo <10 12 A: Dissipative mergers; gradient of gas fraction A1: Not anti-hierarchical for DM halos ! Q: Downsizing? Birnboim & Dekel 03 Dekel & Birnboim 06 Cattaneo, Dekel et al. 06 Neistein, van den Bosch & Dekel 06 Cattaneo, Dekel, Faber 06 Dekel et al. 05; Dekel & Cox 06 Seleson & Dekel 06

Summary Q: z<2: Bright, red & dead E ’ s. No big blues. ………….Bi-modality, environment dependence A: Shutdown in M halo >10 12 Q: z~2-4: Massive, high-SFR disks(?) A: Cold flows even in M halo ~10 12 Trigger: virial shock heating (threshold mass) … …..Maintenance: AGN feedback A2: Shutdown in M halo >10 12 & feedback in M halo <10 12 A1: Not anti-hierarchical for DM halos ! Q: Downsizing? Birnboim & Dekel 03 Dekel & Birnboim 06 Cattaneo, Dekel et al. 06 Neistein, van den Bosch & Dekel 06 Cattaneo, Dekel, Faber 06 cosmic web Seleson & Dekel 2006

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

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

Downsizing Disks and Irregulars E/S0/Sa 0.65<z<0.75 Bell z~3 z~0-1

Downsizing Disks and Irregulars E/S0/Sa 0.65<z<0.75 Bell z~3 z~1 z<1 z~1

Observed Characteristic Scale luminous red galaxies at early times z~0-2 → early star formation, then shutdown very blue gal’s → regulated starbursts bi-modality/transition at M * ~3x10 10 M ʘ ~L * M halo ~6x10 11 M ʘ below: disks, blue, star forming, in field (small halos) above: spheroids, red, old stars, clustered (massive halos) big blue galaxies at very early times z~2-4 → early star formation in big objects

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

t cool <t ff He H2H2 Brems. Rees & Ostriker 77, Silk 77, White & Rees 78 virial velocity log gas density Cooling vs Free Fall H CDM T Blumenthal, Faber, Primack & Rees 86 galaxies clusters upper bound too big

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

A Less Massive Galaxy “ disc ” shocked cold infall T ° K Spherical hydro simulation Birnboim & Dekel M ʘ

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

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

Mass Distribution of Halo Gas density Temperature adiabatic infall shock- heated cold flows disk Analysis of Eulerian hydro simulations by Birnboim, Zinger, Dekel, Kravtsov

Gas through shock: heats to virial temperature compression on a dynamical timescale versus radiative cooling timescale Shock-stability analysis (Birnboim & Dekel 03): post-shock pressure vs. gravitational collapse

Shock Stability (Birnboim & Dekel 03) : post-shock pressure vs. gravitational collapse Birnboim & Dekel 03 with cooling rate q (internal energy e): adiabatic: stable: Stability criterion:

Shock-Heating Scale M vir [M ʘ ] 6x10 11 M ʘ Birnboim & Dekel 03; Dekel & Birnboim 06 stable shock unstable shock V vir [km/s]

Fraction of cold gas in halos: Eulerian simulations Birnboim, Dekel, Kravtsov, Zinger 2006 shock heating z=4 z=1 z=2 z=3

Fraction of cold/hot accretion SPH simulation Keres, Katz, Weinberg, Dav’e 2004 Z=0, under- estimate M shock sharp transition

M vir [M ʘ ] Cold Flows in Typical Halos redshift z σ (22%) 2σ (4.7%) shock heating M * of Press Schechter at z>1 most halos are M<M shock → cold flows

At High z, in Massive Halos: Cold Streams in a Hot Medium Totally hot at z<1 in M>M shock Cold streams at z>2 shock no shock cooling

Cold, dense filaments and clumps (50%) riding on dark-matter filaments and sub-halos Birnboim, Zinger, Dekel, Kravtsov

Cold flows riding dark-matter filaments gas density dark matter gas temperature

Fraction of cold/hot accretion SPH simulation Keres, Katz, Weinberg, Dav’e 2004 cold streams in hot media at high z M>M shock

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

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

Dark-matter filaments one thick filament several thin filaments M~M * M>>M *

Dark-matter inflow in a shell 1-3R vir M~M * M>>M * radial velocity temperature density one thick filament several thin filaments Seleson & Dekel

Dense filaments with radial velocities M~M * M>>M * radial velocities over-density

Dense radial streams into high-sigma halos fraction of mass outside the virial radius with high density & radial motions fraction of halos M>>M * M~M *

Feedback Processes? Once the halo gas is shock heated, what keeps it hot?

M vir [M ʘ ] SN UV on dust AGN + hot medium dynamical friction in groups photo-ionization cold hot feedback strength Supernova feedback is not effective in massive galaxies AGN feedback could be effective in massive galaxies Most efficient star formers: M halo ~ Once the gas is shock heated, what keeps it hot?

Emission Properties vs. Stellar Mass low-mass emission galaxies are almost all star formers high-mass emission galaxies are almost all AGN Kauffmann et al. 2004

M/L M Supernova feedback Shock heating activates AGN feedback Most efficient star formers: M halo ~ has a minimum at M crit Using conditional luminosity function: Van den Bosch, Mo, Yang 03

Supernova Feedback Scale ( Dekel & Silk 86, Dekel & Woo 03 ) Energy fed to the ISM during the “ adiabatic ” phase: Energy required for blowout: SN feedback only in small galaxies

Shock Heating Triggers “AGN Feedback” Kravtsov et al. In M>M shock Enough energy in AGNs (but no characteristic mass) Hot, dilute gas is vulnerable to AGN feedback, while cold streams are shielded Shock heating is the trigger for “AGN fdbk” M shock provides the threshold for shutdown, AGNs may provide long-term maintenance

dark matter gas densitytemperature dark halos Cosmological Hydro Simulations Slyz & Devriendt 2005 dense, cooled gas clumps a dilute medium

dark matter gas densitytemperature dilute gas is pushed away dense clumps are shielded A blast wave expanding in a two-phase medium

Which AGNs do the shutdown?

The clumpy cold flows themselves may provide the maintenance of shutdown Birnboim, Zinger, Dekel, Kravtsov Birnboim & Dekel The role of AGNs in the shutdown may be minor

Origin of the Bi-modality 15 SN feedback vs “AGN feedback” Dekel & Birnboim 06 ungrouped vs grouped cold vs hot

Two Key Processes: Hot medium → halt star formation dilute medium vulnerable to “AGN fdbk” → shock-heated gas never cools → shut down disk and star formation Cold flows → star burst Streams collide near center -- isothermal shock & efficient cooling → dense, cold slab → star burst Disk can survive

From blue sequence to red sequence Dekel & Birnboim 06 M vir [M ʘ ] redshift z all cold hot in hot cold M shock

In a standard Semi Analytic Model (GalICS) not red enough excess of big blue Cattaneo, Dekel, Devriendt, Guiderdoni, Blaizot 05 z=0 data --- sam --- colorcolor color u-r magnitude M r no red sequence at z~1 too few galaxies at z~3 star formation at low z

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

Standard color u-r magnitude M r

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

Environment dependence via halo mass Bulge to disk ratio

stellar mass z=3 z=2 z=1 z=3 z=2 z=1 z=3 z=2 z=1 z=3 z=2 z=1 early growth & shutdown later growth & shutdown very bright blue z~3 ~bright blue z~2 passive How Bright Ellipticals make it to the Red Sequence Two Types of tracks: (Cattaneo, Dekel, Faber 06) dry mergers early wet mergers dry mergers wet mergers magnitude M V

Downsizing: epoch of star formation in E’s Thomas et al. 2005

Kevin Bundy, Caltech Bundy et al 06 Red Blue stellar mass → Downsizing: evolution of mass function since z~1.2 Massive E ’ s are read & dead by z~1, smaller E ’ s become read & dead later

Downsizing due to Shutdown z=1 Cattaneo, Dekel, Faber 2006 z=1 massive normal, central normal, satellite in place by z~1 turn red after z~1

Downsizing due to Shutdown Cattaneo, Dekel, Faber 2006 bright intermediate faint. central central/satellites satellites z=1 magnitude color in place by z~1 turn red after z~1 z=0 z=3 z=2 z=1

Downsizing due to Shutdown z=1 z=0 z=1 z=0 Cattaneo, Dekel, Faber 2006

M halo >10 12 Downsizing by Shutdown at M halo >10 12 z=1 z=2 M halo >10 12 The bright red & dead E ’ s are in place by z~1 while smaller E ’ s appear on the red sequence after z~1 big small z=0 small satellite central

M*M* M vir [M ʘ ] all hot redshift z all cold cold filaments in hot medium M shock big big red & dead already in place by z~1 small central small enter the red sequence after z~1 Downsizing by Shutdown at M halo >10 12 small satellite merge into big halo

M vir [M ʘ ] SN AGN + hot medium cold hot Downsizing by Feedback and Shutdown feedback strength Regulated SFR, keeps gas for later star formation in small halos Shutdown of star formation earlier in massive halos, later in satellites

Is Downsizing Anti-hierarchical? big mass small mass z=1 z=2 z=0 Merger trees of dark-matter halos M>M min Upsizing of mass in main progenitor Downsizing of mass in all progenitors >M min Neistein, van den Bosch, Dekel 2006

Is Downsizing Anti-hierarchical? Downsizing of mass in all progenitors >M min Merger trees of dark-matter halos M>M min Upsizing of mass in main progenitor z=3

Natural Downsizing in Hierarchical Clustering Neistein, van den Bosch, Dekel 2006 Formation time when half the mass has been assembled all progenitors downsizing main progenitor upsizing EPS

Natural Downsizing in Hierarchical Clustering

Conclusions 2. Disk & star formation by cold flows riding DM filaments 3. Early (z>2) big halos (M~10 12 )....big high-SFR galaxies by cold flows in hot media 4. Late (z (groups):...virial shock heating triggers “AGN feedback”. … → shutdown of star formation → red sequence 1. Galaxy type is driven by dark-halo mass:...M crit ~10 12 M ʘ by shock heating (+feedback & clustering) 5. Late (z<2) small halos M<10 12 (field): blue disks M * < Downsizing is seeded in the DM hierarchical clustering 7. Downsizing is shaped up by feedback & shutdown M> Two different tracks from blue to red sequence

Conclusions 2. Disk & star formation by cold flows riding DM filaments 3. Early (z>2) big halos (M~10 12 )....big high-SFR galaxies by cold flows in hot media 4. Late (z (groups):...virial shock heating triggers AGN feedback. … → shutdown of star formation → red sequence 1. Galaxy type is driven by dark-halo mass:...M crit ~10 12 M ʘ by shock heating (+feedback & clustering) 5. Late (z<2) small halos M<10 12 (field): blue disks M * < Downsizing is seeded in the DM hierarchical clustering 7. Downsizing is shaped up by feedback & shutdown M> Fundamental Plane: dissipative mergers & gas gradient

Conclusions 2. Disk & star formation by cold flows riding DM filaments 3. Early (z>2) big halos (M~10 12 )....big high-SFR galaxies by cold flows in hot media 4. Late (z (groups):...virial shock heating triggers AGN feedback. … → shutdown of star formation → red sequence 1. Galaxy type is driven by dark-halo mass:...M crit ~10 12 M ʘ by shock heating (+feedback & clustering) 5. Late (z<2) small halos M<10 12 (field): blue disks M * < Downsizing is seeded in the DM hierarchical clustering 7. Downsizing is shaped up by feedback & shutdown M>10 12

Thank you

Tilted Scaling Relations by Differential Dissipative Mergers non-dissipative dissipative, with gas-fraction declining with mass Dekel & Cox 2006 R M*M*

Structural changes in dissipative mergers Dekel & Cox 2006

Tilted Scaling Relations by Wet Mergers The E scaling relations, including the tilt of the Fundamental Plane and the decline of density with mass can be reproduced by differential dissipation in major mergers. The predicted properties of the progenitors: Structural changes in mergers Gradient of gas fraction consistent with observed gradient along the blue sequence Scaling relations consistent with the simple model of disk formation in LCDM halos SN feedback Top-hat model ~big disks Dekel & Cox 2006

Normal Ellipticals: Central z=1

Normal Ellipticals: Satellites z=1

Talks Oct 03 Venice 30 min Dec 03 IAP EARA workshop 30 Dec 03 Meudon 45 Dec 03 IAP 45 Dec 03 ETH Zurich 45 Jan 04 Oxford ddh+vf 30 and bimodality 45 Feb 04 DM Marina del Rey bimodality30 Apr 04 Texas A&M bimodality30 (45) Apr 04 Berkeley colloq bimodality Apr 04 LNLL May 04 U of Arizona May 04 CfA colloq May 04 UCSB physics colloq May 04 Caltech colloq May 04 UCSC astronomy colloq June 04 KIPAC Stanford colloq July 04 Plumian 300 IoA bi30 (30) August 04 UCSC workshop bi30 (30) August 04 UVic bi50 Oct 04 KITP bi50 Jan 2005, Lyon June 2005, Vulcano June 2005, Ascona Aug 2005 NNG Feb 2006 Netzer TAU March 2006 Venice May 2006 NMSU June 2006 Valencia