Fitting functions for a disk-galaxy model with different LCDM-halo profiles - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




Fitting functions for a disk-galaxy model with different LCDM-halo profiles - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We present an adaptation of the standard scenario of disk-galaxy formation tothe concordant LCDM cosmology aimed to derive analytical expressions for thescale length and rotation speed of present-day disks that form within fourdifferent, cosmologically motivated protogalactic dark matter halo-densityprofiles. We invoke a standard galaxy-formation model that includes virialequilibrium of spherical dark halos, specific angular momentum conservationduring gas cooling, and adiabatic halo response to the gas inflow. The meanmass-fraction and mass-to-light ratio of the central stellar disk are treatedas free parameters whose values are tuned to match the zero points of theobserved size-luminosity and circular speed-luminosity relations of galaxies.We supply analytical formulas for the characteristic size and rotation speed ofdisks built inside Einasto r^{1-6}, Hernquist, Burkert, and Navarro-Frenk-Whitedark matter halos. These expressions match simultaneously the observed zeropoints and slopes of the different correlations that can be built in the RVLspace of disk galaxies from plausible values of the galaxy- and star-formationefficiencies.



Author: L. Darriba, J. M. Solanes

Source: https://arxiv.org/







Related documents