21CMFAST: a fast, seminumerical simulation of the high-redshift 21-cm signal
Abstract
We introduce a powerful seminumeric modelling tool, 21CMFAST, designed to efficiently simulate the cosmological 21-cm signal. Our code generates 3D realizations of evolved density, ionization, peculiar velocity and spin temperature fields, which it then combines to compute the 21-cm brightness temperature. Although the physical processes are treated with approximate methods, we compare our results to a state-of-the-art large-scale hydrodynamic simulation, and find good agreement on scales pertinent to the upcoming observations (≳1 Mpc). The power spectra from 21CMFAST agree with those generated from the numerical simulation to within 10s of per cent, down to the Nyquist frequency. We show results from a 1-Gpc simulation which tracks the cosmic 21-cm signal down from z= 250, highlighting the various interesting epochs. Depending on the desired resolution, 21CMFAST can compute a redshift realization on a single processor in just a few minutes. Our code is fast, efficient, customizable and publicly available, making it a useful tool for 21-cm parameter studies.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2011
- DOI:
- 10.1111/j.1365-2966.2010.17731.x
- arXiv:
- arXiv:1003.3878
- Bibcode:
- 2011MNRAS.411..955M
- Keywords:
-
- methods: numerical;
- galaxies: high redshift;
- dark ages;
- reionization;
- first stars;
- diffuse radiation;
- early Universe;
- large-scale structure of Universe;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 18 pages, 12 figures, MNRAS submitted