THRILS -- The High-(Redshift+Ionization) Line Search: Program Description & Redshift Catalog

TL;DR

The THRILS program uses deep JWST/NIRSpec spectroscopy to study high-redshift galaxies, aiming to understand ionization features, black hole activity, and stellar mass growth in the early universe.

Contribution

This paper introduces the THRILS program and provides a catalog of spectroscopic redshifts for 89 high-redshift galaxy sources.

Findings

Spectroscopic redshifts for 89 sources at z>4.

Detection thresholds established for deep JWST/NIRSpec observations.

Insights into ionization features and black hole activity in early galaxies.

Abstract

To date, many spectroscopic confirmations of z>7 galaxies have been obtained using JWST/NIRSpec prism observations, with most of their physical properties inferred from these observations and corresponding imaging. What is needed are higher-resolution spectra at deeper depths to study these sources in detail. We present The High-(Redshift+Ionization) Line Search (THRILS) program: deep (>8 hr) observations in two pointings of JWST/NIRSpec G395M spectroscopy to 1) probe high ionization spectral features in z>8 galaxies that are indicative of top-heavy initial mass functions or growing massive black holes, 2) search for accreting supermassive black holes in typical galaxies at z~4-9 through broad Balmer line emission, and 3) probe the stellar-mass growth histories of massive galaxies. We include spectroscopic redshift measurements for 89 sources from the THRILS data, as well as a detection threshold for the full and half depth integration times of the program.