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Dark Matter Halos A.Klypin
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2 Major codes: GADET Springel, SDM White PKDGRAV - GASOLINE Quinn, Steidel, Wadsley, Governato, Moore ART Kravtsov, Klypin, N.Gnedin, Gottlober ENZO Bryan, Norman N-body Hydro Cooling/Heating/SF Metal enrichment Radiative transfer Multistepping/Multiple masses
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3 Non-linear evolution: from Zeldovich approximation to DM halos
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7 Local Group:z=0 7
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8 Local Group:z=1 8
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9 Local Group:z=7 9
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10 Mass function of distinct halos It started long ago: 32 years to be precise Now we live through 5th generation of this. Warren etal 2005: 13 sims each with 1G particles
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11 Halo Mass Function depends on environment Sheth&Tormen 2002 Gottl Ö ber etal 2003
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12 Clustering: DM halos and L Conroy, Wechsler, Kravtsov (2005): N-body only Get all halos from high-res simulation Use maximum circular velocity (NOT mass) For subhalos use V max before they became subhalos Every halo (or subhalo) is a galaxy Every halo has luminosity: LF is as in SDSS No cooling or major mergers and such. Only DM halos Reproduces most of the observed clustering of galaxies 12
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13 SDSS DM galaxies DM SDSS: z=0
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14 DEEP: z=1
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15 Dark Matter and Galaxies - Central DM closely correlates with L: Tully- Fisher, Faber-Jackson - Morphology-density relation: morphology is mostly defined by halo mass. - Environment (how many neighbors) is just an indicator of halo mass Young etal(2003-5), Berrier etal(2005) : Halo occupation distribution→the same conclutions
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16 Cusps: simulations Diemand etal 2004
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17 Tasitsiomi etal 2004 Slope gets shallower with decreasing radius, but it does not go below -1 Consistent with what other groups found Navarro etal 2004
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19 Profiles are NOT NFW Navarro etal 2004 Merritt, Navarro 2004 Prada etal 2005 ρ(r)=ρ o exp(-2nr 1/n )+ n=6-8 3D Sersic NFW
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20 Average profiles of Milky Way-size halos
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21 Infall velocities on halos of different mass Prada et al 2005
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22 RMS velocity of isolated halos Full: simulations Dash: solution of Jeans equation
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23 SDSS and LCDM: surface number density of satellites around isolated galaxies LCDM
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24 Evolution of Halo structure Most of the accreted mass stays in the outer region of halo. Diemand etal 2005
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25 Evolution of Halo structure Dwarf Halos at high z cusp evolves very little. Colin etal 2003
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26 Halo Concentrations Bullock etal 2003
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27 Voids R>10Mpc Patiri et al 2006: SDSS
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28 Number-density Profiles of Voids: n(R)/ SDSS LCDM Patiri et al 2006
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DM in central parts of galaxies Adiabatic compression: old approximation Adiabatic compression: Gnedin etal 2004
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How it works
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Structure of our Galaxy Prada etal 2004
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