TY - JOUR
T1 - Probing primordial non-gaussianity with SKA galaxy redshift surveys
T2 - a fully relativistic analysis
AU - Camera, Stefano
AU - Santos, Mário G.
AU - Maartens, Roy
N1 - Erratum: Probing primordial non-Gaussianity with SKA galaxy redshift surveys: A fully relativistic analysis [MNRAS, 448, 2 (2017) (1035-1043)] DOI:10.1093/mnras/stv040
PY - 2015/4/1
Y1 - 2015/4/1
N2 - The Square Kilometre Array (SKA) will produce spectroscopic surveys of tens to hundreds of millions of neutral hydrogen (H I) galaxies, eventually covering 30 000 deg2 and reaching out to redshift z≳2. The huge volumes probed by the SKA will allow for some of the best constraints on primordial non-Gaussianity, based on measurements of the large-scale power spectrum.We investigate various observational set-ups for HI galaxy redshift surveys, compatible with the SKA Phase 1 and Phase 2 (full SKA) configurations.We use the corresponding number counts and bias for each survey from realistic simulations and derive the magnification bias and the evolution of source counts directly from these. For the first time, we produce forecasts that fully include the general relativistic effects on the galaxy number counts. These corrections to the standard analysis become important on very large scales, where the signal of primordial non-Gaussianity grows strongest. Our results showthat, for the full survey, the non-Gaussianity parameter fNL can be constrained down to σ(fNL) = 1.54. This improves the current limit set by the Planck satellite by a factor of 5, using a completely different approach.
AB - The Square Kilometre Array (SKA) will produce spectroscopic surveys of tens to hundreds of millions of neutral hydrogen (H I) galaxies, eventually covering 30 000 deg2 and reaching out to redshift z≳2. The huge volumes probed by the SKA will allow for some of the best constraints on primordial non-Gaussianity, based on measurements of the large-scale power spectrum.We investigate various observational set-ups for HI galaxy redshift surveys, compatible with the SKA Phase 1 and Phase 2 (full SKA) configurations.We use the corresponding number counts and bias for each survey from realistic simulations and derive the magnification bias and the evolution of source counts directly from these. For the first time, we produce forecasts that fully include the general relativistic effects on the galaxy number counts. These corrections to the standard analysis become important on very large scales, where the signal of primordial non-Gaussianity grows strongest. Our results showthat, for the full survey, the non-Gaussianity parameter fNL can be constrained down to σ(fNL) = 1.54. This improves the current limit set by the Planck satellite by a factor of 5, using a completely different approach.
KW - Galaxies
KW - Observations-early universe-large-scale structure of universe-radio lines
KW - Relativistic processes-cosmological parameters-cosmology
KW - RCUK
KW - STFC
KW - ST/K0090X/1
UR - http://www.scopus.com/inward/record.url?scp=84925434914&partnerID=8YFLogxK
U2 - 10.1093/mnras/stv040
DO - 10.1093/mnras/stv040
M3 - Article
AN - SCOPUS:84925434914
SN - 0035-8711
VL - 448
SP - 1035
EP - 1043
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -