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 (≳1Mpc). 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. © 2010 The Authors Monthly Notices of the Royal Astronomical Society © 2010 RAS.

21CMFAST: a fast, seminumerical simulation of the high-redshift 21-cm signal

MESINGER, ANDREI ALBERT;
2011

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 (≳1Mpc). 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. © 2010 The Authors Monthly Notices of the Royal Astronomical Society © 2010 RAS.
2011
Dark ages, reionization, first stars; Diffuse radiation; Early Universe; Galaxies: high redshift; Large-scale structure of Universe; Methods: numerical;
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11384/24320
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 547
  • ???jsp.display-item.citation.isi??? 541
social impact