Abstract
The Complete Calibration of the Color-Redshift Relation (C3R2) survey is
obtaining spectroscopic redshifts in order to map the relation between
galaxy color and redshift to a depth of i ~ 24.5 (AB). The primary goal
is to enable sufficiently accurate photometric redshifts for Stage IV
dark energy projects, particularly Euclid and the Nancy Grace Roman
Space Telescope (Roman), which are designed to constrain cosmological
parameters through weak lensing. We present 676 new high-confidence
spectroscopic redshifts obtained by the C3R2 survey in the 2017B-2019B
semesters using the DEIMOS, LRIS, and MOSFIRE multiobject spectrographs
on the Keck telescopes. Combined with the 4454 redshifts previously
published by this project, the C3R2 survey has now obtained and
published 5130 high-quality galaxy spectra and redshifts. If we restrict
consideration to only the 0.2 < zp < 2.6 range of
interest for the Euclid cosmological goals, then with the current data
release, C3R2 has increased the spectroscopic redshift coverage of the
Euclid color space from 51% (as reported by Masters et al.) to the
current 91%. Once completed and combined with extensive data collected
by other spectroscopic surveys, C3R2 should provide the spectroscopic
calibration set needed to enable photometric redshifts to meet the
cosmology requirements for Euclid, and make significant headway toward
solving the problem for Roman.
Original language | English |
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Number of pages | 12 |
Journal | The Astrophysical Journal Supplement Series |
Volume | 256 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1-Sept-2021 |
Keywords
- Astrophysics - Cosmology and Nongalactic Astrophysics
- Astrophysics - Instrumentation and Methods for Astrophysics