Correlations of DM halo properties: Building the Hyades Suite Jose O˜ norbe Fulbright Postdoctoral Fellow @ University of California Irvine (jonnorbeb@uci.edu) In collaboration with S. Garrison-Kimmel (UCI), J. Bullock (UCI), A. Maller (CUNY), M. Rocha (UCI) and G. Bryan (CU). August 11, 2011 2011 Santa Cruz Galaxy Workshop
Hyades Simulations Suite Zoom-in simulations of galaxy halos spanning M vir = 0 . 05 − 5 E 12 M ⊙ Identical initial conditions ( MUSIC , Hahn & Abel 2011 ) with multiple codes: ENZO , GADGET , GASOLINE Ultimate goal: How robust are halo (& galaxy) properties from code to code? First step: Obtain a reliable and representative sample of halos Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 2
Hyades Simulations Suite z = 0 Volume @ z ini = 250 2 halos same mass @ z=0 Red one would be much quicker run 2 r vir The initial high redshift volume can be defined by the convex hull (minimal polyhedron that englobes all particles) Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 3
Hyades Simulations Suite z = 0 Volume @ z ini = 250 2 halos same mass @ z=0 Red one would be much quicker run 2 r vir Q: How big of a volume do we need to use to get no contamination? Q: Can we pick 5 r vir small volumes without bias? Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 3
Use L box = 50 Mpc / h , N p = 512 3 , ǫ = 1 kpc / h sim to explore how halo properties depend on the vol hz Dark Matter Halo Properties M vir , V max , R max , shape, λ , N neig , a 50 form , N mergers , subhalo, vol hz (1 × r vir ),... Cosmology: Λ CDM WMAP7 Sample: Halos with N part > 500 Which halo properties contain more information? (Skibba & Maccio 2011, Jeeson-Daniel et al. 2011) How can we build a reliable sample with the lowest number of halos? How selective can we be with vol hz ? Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 4
Selecting a Milky Way Halo: How selective can we be? MW Mass bin: [1 − 3] × 10 12 M ⊙ No subhalos How is correlated vol hz for a fixed mass? For some specific halo properties can we choose a low vol hz ? Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 5
Selecting a Milky Way Halo: How selective can we be? MW Mass bin: [1 − 3] × 10 12 M ⊙ No subhalos How is correlated vol hz for a fixed mass? For some specific halo properties can we choose a low vol hz ? Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 5
Selecting a Milky Way Halo: How selective can we be? Color map and black points: full MW sample White points: small initial volume No bias with vol hz Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 6
Testing reliability in Zoom-in simulations Using MUSIC (Hahn & Abel 2011) Set of dark matter zoom-in simulations. m p = 6 . 88 E 7 − 1 . 67 E 4 M ⊙ / h Comparison between Dark-Matter full box and zoom-in runs Initial high-res volume: no contamination and stability of halo parameters. Mass and spatial resolution tests. Lower resolution levels sizes and resolution. Code differences. Katz & White 1993, Klypin et al. 2001 Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 7
Testing reliability in Zoom-in simulations ⋄ ∼ 5 E 12 M ⊙ � ∼ 1 E 12 M ⊙ △ ∼ 5 E 11 M ⊙ Contamination: Any low res particles inside r vir ? Log (Volume computed at high resolution) Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 8
Testing reliability in Zoom-in simulations ⋄ ∼ 5 E 12 M ⊙ � ∼ 1 E 12 M ⊙ △ ∼ 5 E 11 M ⊙ Only runs with no contamination V max and most halo properties are very stable from run to run and as a function of initial volume. Some problems with ENZO because the halo moves within grid... Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 9
Testing reliability in Zoom-in simulations ⋄ ∼ 5 E 12 M ⊙ � ∼ 1 E 12 M ⊙ △ ∼ 5 E 11 M ⊙ Only runs with no contamination Spin parameter less stable Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 10
Conclusions: Preliminary results For a fixed halo mass, there is no strong bias with the initial volume (good news for zoom simulations) Zoom volume need to be at least ∼ 2 × r vir for no contamination within r vir Halo properties are stable for non-contaminated zooms, except for spin parameter. Enzo approach needs higher initial volume and more detailed information on halo history. Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 11
Thank you! Hyades: Daughters of Atlas, nurses of Dionysus. A sisterhood of nymphs that bring rain Ambrosia Coronis Would you like to try Phyto Erudora any Hyades nymph Cardie Niseis with your code? Phaesyle Cleeia Pedile Please contact us!!! Phyto Polyxo Synecho ( jonorbeb@uci.edu ) Niseis Phaeo Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 12
Some Important Parameters Full Box Parameters L box = 50 Mpc / h , ǫ = 1 kpc / h , N part = 512 3 , z ini = 250, m dm = 6 . 88 × 10 7 M ⊙ / h WMAP 7 Cosmology. Model: lcdm + sz + lens Full Box Halo Sample Ω Λ = 0 . 734, Ω m = 0 . 266, N part > 500 → Ω b = 0 . 0449, h = 0 . 71, M > 3 . 4 × 10 10 M ⊙ / h σ 8 = 0 . 801, n s = 0 . 963 ”MW” Mass Bin Halo Sample 1 × 10 12 M ⊙ < M halo < 3 × 10 12 M ⊙ No subhalos Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 13
Other Figures: Full Sample log M vir vs log vol hz : 0.552 3 . 5 3 . 0 log vol hz ( Mpc/h ) 3 com. 2 . 5 2 . 0 1 . 5 1 . 0 0 . 5 11 . 0 11 . 5 12 . 0 12 . 5 13 . 0 log M vir ( M ⊙ /h ) Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 14
Other Figures: MW bin Jose O˜ norbe Correlations of DM halo properties: the Hyades Suite 15
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