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Evolution of Galaxies from HOD Modeling of DEEP2 and SDSS Galaxy Clustering. Zheng Zheng (Institute for Advanced Study) with Alison Coil (University of Arizona) Idit Zehavi (Case Western Reserve University). Hubble Fellows Symposium, STScI, April 20th 2006. Cosmological Model
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Evolution of Galaxies from HOD Modeling of DEEP2 and SDSS Galaxy Clustering Zheng Zheng (Institute for Advanced Study) with Alison Coil (University of Arizona) Idit Zehavi (Case Western Reserve University) Hubble Fellows Symposium, STScI, April 20th 2006
Cosmological Model initial conditions energy & matter contents Galaxy Formation Physics gas dynamics, cooling star formation, feedback m 8ns Dark Halo Population n(M) (r|M) v(r|M) Halo Occupation Distribution P(N|M) spatial bias within halos velocity bias within halos Galaxy Clustering Galaxy-Mass Correlations
Galaxy Samples • DEEP2, z~1 (Coil et al 2006) • SDSS, z~0 (Zehavi et al 2005) • Measurements of two-point correlation functions as a function of luminosity
Two-point correlation function of galaxies Excess probability w.r.t. random distribution of finding galaxy pairs at a given separation 1-halo term Central 2-halo term Satellite
Scatter between galaxy luminosity and host halo mass M1 - mass of halos on average hosting one satellite galaxy above Lmin Mmin - characteristic minimum mass of halos hosting Lmin galaxies Halo Occupation Distribution For a sample of galaxies more luminous than Lmin
Modeling results DEEP2 galaxies L
Establishing an evolution link between DEEP2 and SDSS galaxies
z~1 z~1 Star Formation Merging Merging z~0 z~0 Stellar mass evolution
Stellar mass evolution (z~1 to z~0) as a function of halo mass Tentative conclusion: For central galaxies in z~0 M<1012 h-1Msun halos, ~80% of their stars form after z~1 For central galaxies in z~0 M>1012 h-1Msun halos, ~60% of their stars form after z~1
Summary & Future Work HODs at z~1 and z~0 from modeling two-point correlation functions of DEEP2 and SDSS galaxies Evolution link through halo evolution Stellar mass evolution from z~1 to z~0 for central galaxies as a function of halo mass (pure merger vs star formation) Useful constraints to galaxy formation models Clustering measurements for galaxy samples based on stellar mass Galaxy samples at different redshifts Evolution of satellite galaxies