Primordial non-Gaussianities in the intergalactic medium
Abstract
We present results from the first high-resolution hydrodynamical simulations of non-Gaussian cosmological models. We focus on the statistical properties of the transmitted Lyman-α flux in the high-redshift intergalactic medium. Imprints of non-Gaussianity are present and are larger at high redshifts. Differences larger than 20 per cent at z > 3 in the flux probability distribution function for high-transmissivity regions (voids) are expected for values of the non-linearity parameter fNL = +/-100 when compared to a standard Λ cold dark matter cosmology with fNL = 0. We also investigate the one-dimensional flux bispectrum: at the largest scales (corresponding to tens of Mpc), we expect deviations in the flux bispectrum up to 20 per cent at z ~ 4 (for fNL = +/-100), significantly larger than deviations of ~3 per cent in the flux power spectrum. We briefly discuss possible systematic errors that can contaminate the signal. Although challenging, a detection of non-Gaussianities in the interesting regime of scales and redshifts probed by the Lyman-α forest could be possible with future data sets.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- March 2009
- DOI:
- 10.1111/j.1365-2966.2008.14236.x
- arXiv:
- arXiv:0811.2223
- Bibcode:
- 2009MNRAS.393..774V
- Keywords:
-
- quasars: absorption lines;
- cosmology: observations;
- cosmology: theory;
- Astrophysics
- E-Print:
- 10 pages, 7 figures. Accepted for publication in MNRAS