Baryonic Features in the Matter Transfer Function
Abstract
We provide scaling relations and fitting formulae for adiabatic cold dark matter cosmologies that account for all baryon effects in the matter transfer function to better than 10% in the largescale structure regime. They are based upon a physically wellmotivated separation of the effects of acoustic oscillations, Compton drag, velocity overshoot, baryon infall, adiabatic damping, Silk damping, and cold dark matter growth suppression. We also find a simpler, more accurate, and better motivated form for the zerobaryon transfer function than previous works. These descriptions are employed to quantify the amplitude and location of baryonic features in linear theory. While baryonic oscillations are prominent if the baryon fraction Ω_{b}/Ω_{0} >~ Ω_{0}h^{2} + 0.2, the main effect in more conventional cosmologies is a sharp suppression in the transfer function below the sound horizon. We provide a simple but accurate description of this effect and stress that it is not well approximated by a change in the shape parameter Γ.
 Publication:

The Astrophysical Journal
 Pub Date:
 March 1998
 DOI:
 10.1086/305424
 arXiv:
 arXiv:astroph/9709112
 Bibcode:
 1998ApJ...496..605E
 Keywords:

 COSMOLOGY: THEORY;
 COSMOLOGY: DARK MATTER;
 COSMOLOGY: LARGESCALE STRUCTURE OF UNIVERSE;
 Cosmology: Theory;
 Cosmology: Dark Matter;
 Cosmology: LargeScale Structure of Universe;
 Astrophysics
 EPrint:
 20 pages, LaTeX, 7 Postscript figures included. Submitted to ApJ. Electronic versions of formulae are available at http://www.sns.ias.edu/~whu/transfer/transfer.html