Toward a Measurement of the Cosmological Geometry at z ~ 2: Predicting Lyα Forest Correlation in Three Dimensions and the Potential of Future Data Sets

By P. Mcdonald. 2001

220 citations recorded by the source corpus.

The correlation between Lyα absorption in the spectra of quasar pairs can be used to measure the transverse distance scale at z ~ 2, which is sensitive to the cosmological constant (ΩΛ) or other forms of vacuum energy. Using hydro-PM simulations, I compute the three-dimensional power spectrum of the Lyα forest flux, PF(), from which the redshift-space anisotropy of the correlation can be obtained. I compute directly the linear theory bias parameters of the Lyα forest, potentially allowing simulation results to be extended to arbitrarily large scales. I investigate the dependence of PF() on the primordial power spectrum, the temperature-density relation of the gas, and the mean flux decrement, finding that the redshift-space anisotropy is relatively insensitive to these parameters. A table of results is provided for different parameter variations. I investigate the constraint that can be obtained on ΩΛ using quasars from a large survey. Assuming 13 2 pairs at a separation of less than θ and including separations less than 10', a measurement to ≲ 5% can be made if simulations can predict the redshift-space anisotropy with ≲ 5% accuracy or to ≲ 10% if the anisotropy must be measured from the data. The Sloan Digital Sky Survey (SDSS) will obtain spectra for a factor of ~5 fewer pairs than this, so follow-up observations of fainter pair candidates will be necessary. I discuss the requirements on the spectral resolution and signal-to-noise ratio (SDSS quality spectra are sufficient). I find that a box size of ~40 h-1 Mpc and a resolution of ~40 h-1 kpc are necessary for convergence of the calculations to ≲ 5% on all relevant scales, although somewhat poorer resolution can be used for large scales.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/cef25bae9ae27b342ee0fa04d5d3784cbc98771e

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Citations in the corpus

Baryon Acoustic Oscillations in the Ly-\alpha\ forest of BOSS quasars (2012, methodology): “…that, on large scales, the mean Lyα absorption is a linear tracer of the mass overdensity (Croft et al., 1997, 1998; Weinberg et al., 1998; McDonald et al., 2000; McDonald , 2003), implying a relation of the power spectrum of the measured absorption to that of the underlying mass fluctuations.”
The Completed SDSS-IV Extended Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations with Lyα Forests (2020, background): “Even though this continuous tracer of the matter density fluctuations has a lower bias than discrete tracers, the statistical power from the large wavelength range where Lyαabsorption can be measured allows the observation of BAOs, as suggested by McDonald (2003) and White (2003).”
Measurement of baryon acoustic oscillations in the Lyman-α forest fluctuations in BOSS data release 9 (2013, methodology): “Therefore, measuring three-dimensional (3D) correlations in the flux fluctuations of the Lyman-α forest provides an accurate method for detecting BAO correlations [23–25].”
Primordial Black Holes as Dark Matter: The Power Spectrum and Evaporation of Early Structures (2003, methodology): “We have not yet performed fully hydrodynamic simulations using PBH power spectra, so our result is based entirely on hydro-PM simulations (e.g., Gnedin & Hui 1998; McDonald, MiraldaEscudé, & Cen 2002; McDonald 2003).”
Baryon acoustic oscillations from the complete SDSS-III Ly$\alpha$-quasar cross-correlation function at $z=2.4$ (2017, methodology): “It can be chosen to be of one of the two forms given by Equation 21 of (McDonald 2003) or as presented in Arinyo-i-Prats et al. (2015).”
Lyman-alpha forests cool warm dark matter (2015, methodology): “Using a splicing technique described in [34] and first applied in [16, 35], we infer the flux power spectrum of an equivalent (L = 100 h−1 Mpc, N = 3072) simulation from a combination of three lesser ones: a scaled-down (25, 768) to provide high resolution on small scales, a large-box low-resolution”
Baryon acoustic oscillations at z = 2.34 from the correlations of Lyα absorption in eBOSS DR14 (2019, methodology): “Such measurements at z ≈ 2.4 were suggested by McDonald (2003) and McDonald & Eisenstein (2007).”
Target Selection and Validation of DESI Quasars (2022, background): “This field of research has developed over more than two decades (McDonald 2003; Busca et al. 2013; Slosar et al. 2013) and reached its peak with the two recent publications of eBOSS (Chabanier et al. 2019; du Mas des Bourboux et al. 2020).”