Renyue Cen

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We analyze the SDSS Lyα forest P F (k, z) measurement to determine the linear theory power spectrum. Our analysis is based on fully hydrodynamic simulations, extended using hydro-PM simulations. We account for the effect of absorbers with damping wings, which leads to an increase in the slope of the linear power spectrum. We break the de-generacy between(More)
The evolution of the temperature in the intergalactic medium is related to the reion-ization of hydrogen and helium, and has important consequences for our understanding of the Lyα forest and of galaxy formation in gravitational models of large-scale structure. We measure the temperature-density relation of intergalactic gas from Lyα forest observations of(More)
Approximately 30 − 40% of all baryons in the present day universe reside in a warm-hot intergalactic medium (WHIM), with temperatures between 10 5 < T < 10 7 K. This is a generic prediction from six hydrodynamic simulations of currently favored structure formation models having a wide variety of numerical methods, input physics, volumes, and spatial(More)
We have examined the properties of shock waves in simulations of large scale structure formation. Two cosmological scenarios have been considered: a standard cold dark matter model with Ω M = 1 (SCDM) and a cold dark matter model with cosmological constant and Ω M + Ω Λ = 1 (ΛCDM) having Ω Λ = 0.55. Large-scale shocks result from accretion onto sheets,(More)
  • Renyue Cen, Jeremiah P Ostriker, Received Accepted
  • 1998
New, high resolution, large-scale, cosmological hydrodynamic galaxy formation simulations of a standard cold dark matter model (with a cosmological constant) are utilized to predict the distribution of baryons at the present and at moderate redshift. It is found that the average temperature of baryons is an increasing function of time, with most of the(More)
  • Russell M Kulsrud, Renyue Cen, Jeremiah P Ostriker, Dongsu Ryu, Received Accepted
  • 1997
It is demonstrated that strong magnetic fields are produced from a zero initial magnetic field during the pregalactic era, when galaxies are first forming. Their development proceeds in three phases. In the first phase, weak magnetic fields are created by the Biermann battery mechanism, acting in shocked parts of the intergalactic medium where caustics form(More)
Using large-scale hydrodynamic simulations with heuristic criteria for galaxy formation, we investigate how the galaxy field is related to physical parameters, such as the mass density and the gas temperature. We find that the relation between the galaxy and mass density fields is a function of scale. The bias b(R) ≡ σ g (R)/σ(R), where σ g (R) is the(More)
The dynamics of Local Group and its environment provide a unique challenge to cosmological models. The velocity field within 5h −1 Mpc of the Local Group (LG) is extremely " cold ". The deviation from a pure Hubble flow, characterized by the observed radial peculiar velocity dispersion, is measured to be ∼ 60km s −1. We compare the local velocity field with(More)