vix.ing · top · new · best · stats · spec

OBSERVATIONAL REQUIREMENTS FOR Lyα FOREST TOMOGRAPHIC MAPPING OF LARGE-SCALE STRUCTURE ATz∼ 2

2013/09/30 by Khee-Gan Lee, Joseph F. Hennawi, Martin White +3
Physics and Astronomy · #Angstrom #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Image resolution #Limiting #Noise (video) #Radio Astronomy Observations and Technology #Spectral line #TRACE (psycholinguistics) #Transverse plane #astro-ph.CO

paper · pdf · doi:10.1088/0004-637x/788/1/49

published as 2014 ApJ, 788, 49 · 18 pages, 10 figures. Accepted by ApJ

arxiv created 2014/05/15 · openalex publication_date 2014/05/21 · arxiv updated 2014/05/23 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

The z ≳ 2 Lyα forest traces the underlying dark matter distribution on large scales and, given sufficient sightlines, can be used to create three-dimensional (3D) maps of large-scale structures. We examine the observational requirements to construct such maps and estimate the signal-to-noise as a function of exposure time and sightline density. Sightline densities at z = 2.25 are n los ≈ [360, 1200, 3300] deg −2 at limiting magnitudes of g = [24.0, 24.5, 25.0], resulting in transverse sightline separations of 〈 d ⊥ 〉 ≈ [3.6, 1.9, 1.2] h −1 Mpc, which roughly sets the reconstruction scale. We simulate these reconstructions using mock spectra with realistic noise properties and find that spectra with S/N ≈ 4 per angstrom can be used to generate maps that clearly trace the underlying dark matter at overdensities of ρ/〈ρ〉 ∼ 1. For the VLT/VIMOS spectrograph, exposure times t exp = [4, 6, 10] hr are sufficient for maps with spatial resolution 3D = [5.0, 3.2, 2.3] h −1 Mpc. Assuming ∼250 h −1 Mpc is probed along the line of sight, 1 deg 2 of survey area would cover a comoving volume of ≈10 6 h −3 Mpc 3 at 〈 z 〉 ∼ 2.3, enabling the efficient mapping of large volumes with 8–10 m telescopes. These maps could be used to study galaxy environments, the topology of large-scale structures at high z , and to detect proto-clusters.

Citations