Simulating Galaxies and the Universe Joel R. Primack University of California, Santa Cruz Tuesday, June 26, 12
Hubble Space Telescope Ultra Deep Field - ACS This picture is beautiful but misleading, since it only shows about 0.5% of the cosmic density. The other 99.5% of the universe is invisible. Tuesday, June 26, 12
DARK MATTER + DARK ENERGY = DOUBLE DARK THEORY Technical Name: Lambda Cold Dark Matter ( Λ CDM) Tuesday, June 26, 12
Matter and Energy Content of the Universe Imagine that the entire universe is an ocean of dark energy. On that ocean sail billions of ghostly ships made of dark matter... Tuesday, June 26, 12
Matter and Energy Content of the Dark Universe Matter Ships on a Λ CDM Dark Double Energy Dark Ocean Imagine that the entire Theory universe is an ocean of dark energy. On that ocean sail billions of ghostly ships made of dark matter... Tuesday, June 26, 12
Big Bang Data Agree with Double Dark Theory Tuesday, June 26, 12
Distribution of Matter Also Agrees with Double Dark Theory! Double Dark Theory Tuesday, June 26, 12
Because the Λ CDM Dark Energy + Cold Dark Matter (Double Dark) theory of structure formation is now so well confirmed by observations, we study the predictions of this theory for the formation of dark matter structure in the universe and use this to improve our understanding of the visible objects that we can see with our telescopes: galaxies, clusters, and the large-scale structure of the universe. Tuesday, June 26, 12
Cosmological Simulations Astronomical observations represent snapshots of moments in time. It is the role of astrophysical theory to produce movies -- both metaphorical and actual -- that link these snapshots together into a coherent physical theory. Cosmological dark matter simulations show large scale structure, growth of structure, and dark matter halo properties Hydrodynamic galaxy formation simulations: evolution of galaxies, formation of galactic spheroids via mergers, galaxy images in all wavebands including stellar evolution and dust Tuesday, June 26, 12
Tuesday, June 26, 12
Dark Matter Expanding Tuesday, June 26, 12
Expansion.... z=2.95 z=49.00 z=12.01 t=2.23 t=49 t=374M Myr yr Gyr Tuesday, June 26, 12
t = 13.7 Gyr (today) t = 6.66 Gyr Wild Space Tame Tame Space Space End of expansion for this halo Tuesday, June 26, 12
Aquarius Simulation Milky Way 100,000 Light Years Milky Way Dark Matter Halo 1,500,000 Light Years 14 Tuesday, June 26, 12
Tuesday, June 26, 12
Bolshoi Cosmological Simulation 1 Billion Light Years Tuesday, June 26, 12
Bolshoi Cosmological Simulation 100 Million Light Years 1 Billion Light Years Tuesday, June 26, 12
Bolshoi Cosmological Simulation 100 Million Light Years Tuesday, June 26, 12
Bjork “Dark Matter” Biophilia Tuesday, June 26, 12
The Millennium Run • void statistics , • properties of including sizes and halos (radial profile, shapes and their concentration, evolution, and the shapes) orientation of halo • evolution of the spins around voids number density of • quantitative halos , essential for descriptions of the normalization of Press- evolving cosmic Schechter- type models web , including • evolution of the applications to weak distribution and gravitational lensing clustering of halos • preparation of mock in real and redshift catalogs , essential space, for comparison with observations for analyzing SDSS • accretion history and other survey of halos , assembly data, and for bias (variation of large- preparing for new scale clustering with as- large surveys for dark sembly history), and energy etc. correlation with halo properties including • merger trees , angular momenta and essential for semi- shapes analytic modeling of • halo statistics the evolving galaxy including the mass and population, including velocity functions, models for the galaxy angular momentum and shapes, subhalo merger rate, the numbers and history of star distribution, and formation and galaxy correlation with colors and environment morphology, the evolving AGN luminosity function, stellar and AGN feedback, recycling of gas and metals, etc. Springel et al. 2005 Tuesday, June 26, 12
WMAP-only Determination of σ 8 and Ω M ● WMAP1 2003 Text Text Text Text Text Text Text Text Text Text Text Text Text Text WMAP7 2010 ● ● WMAP5 2008 WMAP3 2006 ● Tuesday, June 26, 12
WMAP+SN+Clusters Determination of σ 8 and Ω M Tuesday, June 26, 12
WMAP+SN+Clusters Determination of σ 8 and Ω M Millennium is now about 4 σ away from observations WMAP7 ● WMAP5 ● Tuesday, June 26, 12
Cosmological parameters are consistent with the latest observations Force and Mass Resolution are nearly an order of magnitude better than Millennium-I σ 8 = 0.82 h = 0.70 Force resolution is the same as Millennium-II, in a volume 16x larger Halo finding is complete to V circ > 50 km/s, 0 using both BDM and ROCKSTAR halo finders Bolshoi and MultiDark halo catalogs were released in September 2011 at Astro Inst Potsdam; Merger Trees will soon be available Tuesday, June 26, 12
The Milky Way has two large satellite galaxies, the small and large Magellanic Clouds The Bolshoi simulation + halo abundance matching predicts the likelihood of this Tuesday, June 26, 12
0 1 2 0 1 2 Tuesday, June 26, 12
Apply the same absolute magnitude and isolation cuts Statistics of MW bright satellites: to Bolshoi+SHAM galaxies as SDSS data vs. Bolshoi simulation to SDSS: Identify all objects with 1.000 absolute 0.1 M r = -20.73±0.2 M r,host = -20.73±0.2 and observed m r < 17.6 Probe out to z = 0.15, a M r,sat = M r,host + (2 − 4) volume of roughly 500 (Mpc/ h) 3 0.100 leaves us with 3,200 objects. Probability Comparison of Bolshoi with SDSS observations is in 0.010 close agreement, well within Every case agrees within observed statistical error observational errors! bars. SDSS # of Subs Prob (obs) Prob (sim) Simulation 0.001 0 60% 61% 0 1 2 3 4 5 # of Satellites 1 22% 25% Busha et al. 2011 ApJ Risa Wechsler 2 13% 8.1% Liu et al. 2011 ApJ 3 4% 3.2% Similarly good agreement with SDSS for brighter satellites with 4 1% 1.4% spectroscopic redshifts compared with Millennium-II using abundance matching -- Tollerud, Boylan-Kolchin, et al. 2011 ApJ 5 0% 0.58% Tuesday, June 26, 12
BigBolshoi / MultiDark Same cosmology as Bolshoi: h=0.70, σ 8 =0.82, n=0.95, Ω m =0.27 7 kpc/h resolution, complete to V circ > 170 km/s Volume 64x larger than Bolshoi 4 Billion Light Years Tuesday, June 26, 12
dark matter simulation - expanding with the universe same simulation - not showing expansion Tuesday, June 26, 12
CONSTRAINED LOCAL UNIVERSE SIMULATION 300 Million Light Years Tuesday, June 26, 12
31 Tuesday, June 26, 12
Virgo Cluster MWy & M31 Fornax Cluster Tuesday, June 26, 12
Bolshoi Merger Tree for the Formation of a Big Cluster Halo SDSSBolshoiMpc_USE_THIS_ONE Peter Behroozi Tuesday, June 26, 12
Blumenthal, Feber, Primack, & Rees -- Nature 311, 517 (1984) Galaxies form beneath the cooling curves Galaxy groups and clusters form above the cooling curves Star Forming Band: 10 10 - 10 12 Msun Tuesday, June 26, 12
Implications and Predictions of the Model Massive galaxies: M halo ---> Started forming stars early. Shut down early. w w w w w w w w Are red today. star-forming band Populate dark halos that are much more massive than their stellar mass. <--- time Small galaxies: “D o w n s i z i n g” Started forming stars late. Star formation is a wave that Are still making stars today. started in the largest galaxies and Are blue today. swept down to smaller masses later (Cowie et al. 1996). Populate dark halos that match their stellar mass. Sandy Faber Tuesday, June 26, 12
cQ Evolution of Galaxies: Observations vs. Theory dQ cQ dSF cSF Barro et al. (2012 - Hubble Observations) cQ Astrophysical DM Halo processes modeled: Merger cSF • shock heating & radiative Tree cooling • photoionization squelching • merging • star formation (quiescent & time burst) • SN heating & SN-driven winds • AGN accretion and feedback • chemical evolution • stellar populations & dust Porter et al. (in prep.) - Bolshoi SAM Tuesday, June 26, 12
Evolution of Compact Star- Observed Evolution of Forming Galaxies Galaxies from Latest According to Bolshoi-based Hubble Telescope Data Semi-Analytic Model dQ cQ dSFG cSFG Gas-rich merger in past Gyr cSFG at z = 2.4 Barro et al. (2012 - Hubble Observations) Gas-poor merger in past Gyr Porter et al. (in prep.) - Bolshoi SAM Tuesday, June 26, 12
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