Measuring BAO and non-Gaussianity via QSO clustering

Sawangwit, U., Shanks, T., Croom, S. M., Drinkwater, M. J., Fine, S., Parkinson, D. and Ross, Nicholas P. (2012) Measuring BAO and non-Gaussianity via QSO clustering. Monthly Notices of the Royal Astronomical Society, 420 3: 1916-1925. doi:10.1111/j.1365-2966.2011.19848.x

Author Sawangwit, U.
Shanks, T.
Croom, S. M.
Drinkwater, M. J.
Fine, S.
Parkinson, D.
Ross, Nicholas P.
Title Measuring BAO and non-Gaussianity via QSO clustering
Journal name Monthly Notices of the Royal Astronomical Society   Check publisher's open access policy
ISSN 0035-8711
Publication date 2012-03
Sub-type Article (original research)
DOI 10.1111/j.1365-2966.2011.19848.x
Open Access Status DOI
Volume 420
Issue 3
Start page 1916
End page 1925
Total pages 10
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Collection year 2013
Language eng
Formatted abstract
Our goals are (i) to search for BAO and large-scale structure in current quasi-stellar object (QSO) survey data and (ii) to use these and simulation/forecast results to assess the science case for a new, >10 times larger, QSO survey. We first combine the Sloan Digital Sky Survey (SDSS), 2dF QSO Redshift Survey (2QZ) and 2dF-SDSS LRG and QSO (2SLAQ) surveys to form a survey of ≈60 000 QSOs. We find a hint of a peak in the QSO two-point correlation function, ξ (s), at the same scale (≈105 h−1 Mpc) as detected by Eisenstein et al. in their sample of Data Release 5 (DR5) Luminous Red Galaxies (LRGs) but only at low statistical significance.We then compare these data with QSO mock catalogues from the Hubble Volume N-body light-cone simulation used by Hoyle et al. and find that both routes give statistical error estimates that are consistent at ≈100 h−1 Mpc scales. Mock catalogues are then used to estimate the nominal survey size needed for a 3–4σ detection of the Baryon Acoustic Oscillations (BAO) peak.We find that a redshift survey of ≈250 000 ȥ < 2.2 QSOs is required over ≈3000 deg2. This is further confirmed by static lognormal simulations where the BAO are clearly detectable in the QSO power spectrum and correlation function. The nominal survey would on its own produce the first detection of, for example, discontinuous dark energy evolution in the so far uncharted 1 < ȥ < 2.2 redshift range.We further find that a survey with ≈50 per cent higher QSO sky densities and 50 per cent bigger area will give an ≈6σ BAO detection, leading to an error ≈60 per cent of the size of the BOSS error on the dark energy evolution parameter, wa. Another important aim of a QSO survey is to place newlimits on primordial non-Gaussianity at large scales. In particular, it is important to test tentative evidence we have found for the evolution of the linear form of the combined SDSS+2QZ+2SLAQ QSO ξ (s) at ȥ ≈1.6, which may be caused by the existence of non-Gaussian clustering features at high redshift. Such a QSO survey will also determine the gravitational growth rate at ȥ≈ 1.6 via redshift-space distortions, allow lensing tomography via QSO magnification bias while also measuring the exact luminosity dependence of small-scale QSO clustering.
Keyword Quasars: general
Cosmology: observations
Dark energy
Distance scale
Large-scale structure of Universe
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
Official 2013 Collection
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Citation counts: TR Web of Science Citation Count  Cited 8 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 10 times in Scopus Article | Citations
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