Title: Improving photometric redshifts with Lyα tomography

Abstract

Forming a three dimensional view of the Universe is a long-standing goal of astronomical observations, and one that becomes increasingly di cult at high redshift. In this paper we discuss how tomography of the intergalactic medium (IGM) at z ≃ 2:5 can be used to estimate the redshifts of massive galaxies in a large volume of the Universe based on spectra of galaxies in their background. Our method is based on the fact that hierarchical structure formation leads to a strong dependence of the halo density on large-scale environment. A map of the latter can thus be used to re ne our knowledge of the redshifts of halos and the galaxies and AGN which they host. We show that tomographic maps of the IGM at a resolution of 2.5 h^-1Mpc can determine the redshifts of more than 90 per cent of massive galaxies with redshift uncertainty Δz=(1+z) = 0:01. Higher resolution maps allow such redshift estimation for lower mass galaxies and halos.

Authors:

Schmittfull, Marcel ^[1]; White, Martin ^[2]

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+ Show Author Affiliations

1. Univ. of California, Berkeley, CA (United States)
2. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Publication Date:

Thu Aug 11 00:00:00 EDT 2016

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1530259

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Monthly Notices of the Royal Astronomical Society

Additional Journal Information:

Journal Volume: 463; Journal Issue: 1; Journal ID: ISSN 0035-8711

Publisher:

Royal Astronomical Society

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS