The Astronomical Journal (Jan 2025)

Simulating Continuum-based Redshift Measurement in the Roman’s High Latitude Spectroscopic Survey

  • Zhiyuan Guo,
  • Bhavin Joshi,
  • C. W. Walter,
  • M. A. Troxel

DOI
https://doi.org/10.3847/1538-3881/adcd6b
Journal volume & issue
Vol. 169, no. 6
p. 320

Abstract

Read online

We investigate the capability of the Nancy Grace Roman Space Telescope’s (Roman) Wide-Field Instrument G150 slitless grism to detect red, quiescent galaxies based on the current reference survey. We simulate dispersed images for Roman reference High-Latitude Spectroscopic Survey (HLSS) and analyze two-dimensional spectroscopic data using the grism Redshift and Line Analysis ( Grizli ) software. This study focus on assessing Roman grism’s capability for continuum-level redshift measurement for a redshift range of 0.5 ≤ z ≤ 2.5. The redshift recovery is assessed by setting three requirements of: ${\sigma }_{z}=\frac{\left|z-{z}_{{\rm{true}}}\right|}{1+z}\,\leqslant \,0.01$ , signal-to-noise ratio≥ 5 and the presence of a single dominant peak in redshift likelihood function. We find that, for quiescent galaxies, the reference HLSS can reach a redshift recovery completeness of ≥50% for F158 magnitude brighter than 20.2 mag. We also explore how different survey parameters, such as exposure time and the number of exposures, influence the accuracy and completeness of redshift recovery, providing insights that could optimize future survey strategies and enhance the scientific yield of the Roman in cosmological research.

Keywords