Large-Scale Structure in Mixed Dark Matter Models with a Nonthermal Volatile Component

Abstract

view Abstract Citations (8) References (59) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Large-Scale Structure in Mixed Dark Matter Models with a Nonthermal Volatile Component Pierpaoli, Elena ; Coles, Peter ; Bonometto, Silvio ; Borgani, Stefano Abstract We investigate the properties of large-scale structure predicted in a class of mixed dark matter models in which the volatile component (made of particles with high rms velocity) derives from the decay of a heavier particle. Such models based on cold + volatile dark matter (CVDM) differ from the standard mixture of CDM and massive neutrinos, usually known as CHDM, in that they involve a component which has a nonthermal phase-space distribution function. As a consequence, and differently from CHDM models, the value of the redshift at which volatile particles become nonrelativistic, z_nr_, can be varied almost independently of the volatile fraction, {OMEGA}_X_. We compute transfer functions for a selection of such models, having 0.1 <= {OMEGA}_X_ <= 0.5 and different values of z_nr_. Using linear theory and assuming a scale-free primordial spectrum, we compare such models with observational constraints on large- scale galaxy clustering and bulk flows, as well as on the abundance of galaxy clusters and high-redshift damped Lyα systems. We find that these constraints enable us to discriminate between different {OMEGA}_x_ and z_nr_; within the range of the models inspected, those that can be accommodated most easily by the data correspond to the parameter choice {OMEGA}_X_ ~ 0.2 and z_nr_ ~2 x 10^4OMEGA_X_. Publication: The Astrophysical Journal Pub Date: October 1996 DOI: 10.1086/177852 arXiv: arXiv:astro-ph/9603150 Bibcode: 1996ApJ...470...92P Keywords: COSMOLOGY: LARGE-SCALE STRUCTURE OF UNIVERSE; GALAXIES: CLUSTERS: GENERAL; COSMOLOGY: DARK MATTER; Astrophysics E-Print: 20 pages LateX file, plus 4 ps-figures. Accepted for publication in ApJ full text sources arXiv | ADS |