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Physical Sciences and Mathematics Commons

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Astrophysics and Astronomy

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Astronomy Department Faculty Publication Series

2002

Quasars : absorption lines

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Toward A Precise Measurement Of Matter Clustering: Ly Alpha Forest Data At Redshifts 2-4, Rac Croft, Dh Weinberg, M Bolte, S Burles, L Hernquist, N Katz, D Kirkman, D Tytler Jan 2002

Toward A Precise Measurement Of Matter Clustering: Ly Alpha Forest Data At Redshifts 2-4, Rac Croft, Dh Weinberg, M Bolte, S Burles, L Hernquist, N Katz, D Kirkman, D Tytler

Astronomy Department Faculty Publication Series

We measure the filling factor, correlation function, and power spectrum of transmitted flux in a large sample of Lyα forest spectra, comprised of 30 Keck HIRES spectra and 23 Keck LRIS spectra. We infer the linear matter power spectrum P(k) from the flux power spectrum PF(k), using an improved version of the method of Croft et al. that accounts for the influence of redshift-space distortions, nonlinearity, and thermal broadening on the shape of PF(k). The evolution of the shape and amplitude of P(k) over the redshift …


Comparing Simulations And Observations Of The Ly Alpha Forest. I. Methodology, Ce Petry, Cd Impey, N Katz, Dh Weinberg, Le Hernquist Jan 2002

Comparing Simulations And Observations Of The Ly Alpha Forest. I. Methodology, Ce Petry, Cd Impey, N Katz, Dh Weinberg, Le Hernquist

Astronomy Department Faculty Publication Series

We describe techniques for comparing spectra extracted from cosmological simulations and observational data, using the same methodology to link Lyα properties derived from the simulations with properties derived from observational data. The eventual goal is to measure the coherence or clustering properties of Lyα absorbers using observations of quasar pairs and groups. We quantify the systematic underestimate in opacity that is inherent in the continuum-fitting process of observed spectra over a range of resolution and signal-to-noise ratio (S/N). We present an automated process for detecting and selecting absorption features over the range of resolution and S/N of typical observational data …