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arXiv · 2512.12509

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

Taylor A. Hutchison·Rebecca L. Larson·Pablo Arrabal Haro·Erini Lambrides·Katherine Chworowsky·Gourav Khullar·Kelcey Davis·Steven L. Finkelstein·Jane R. Rigby·Guillermo Barro·Nikko J. Cleri·Dale Kocevski·Jacqueline Antwi-Danso·Mic Bagley·Danielle A. Berg·Volker Bromm·Oscar Chavez Ortiz·John Chisholm·Sadie C. Coffin·M. C. Cooper·Olivia Cooper·Isa G. Cox·Mark Dickinson·Harry Ferguson·Maximilien Franco·Jonathan P. Gardner·Ananya Ganapathy·Norman Grogin·Michaela Hirschmann·Marc Huertas-Company·Intae Jung·Jeyhan S. Kartaltepe·Anton M. Koekemoer·Ray A. Lucas·Elizabeth McGrath·Alexa M. Morales·Grace M. Olivier·Casey Papovich·Pablo G. Perez-Gonzalez·Nor Pirzkal·Rachel S. Somerville·Anthony J. Taylor·Jonathan R. Trump·Brittany Vanderhoof·Benjamin Weiner·Brian Welch·L. Y. Aaron Yung·Jorge A. Zavala·the THRILS collaboration
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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.

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Taylor A. Hutchison, Rebecca L. Larson, Pablo Arrabal Haro, Erini Lambrides, Katherine Chworowsky, Gourav Khullar, Kelcey Davis, Steven L. Finkelstein, Jane R. Rigby, Guillermo Barro, Nikko J. Cleri, Dale Kocevski, Jacqueline Antwi-Danso, Mic Bagley, Danielle A. Berg, Volker Bromm, Oscar Chavez Ortiz, John Chisholm, Sadie C. Coffin, M. C. Cooper, Olivia Cooper, Isa G. Cox, Mark Dickinson, Harry Ferguson, Maximilien Franco, Jonathan P. Gardner, Ananya Ganapathy, Norman Grogin, Michaela Hirschmann, Marc Huertas-Company, Intae Jung, Jeyhan S. Kartaltepe, Anton M. Koekemoer, Ray A. Lucas, Elizabeth McGrath, Alexa M. Morales, Grace M. Olivier, Casey Papovich, Pablo G. Perez-Gonzalez, Nor Pirzkal, Rachel S. Somerville, Anthony J. Taylor, Jonathan R. Trump, Brittany Vanderhoof, Benjamin Weiner, Brian Welch, L. Y. Aaron Yung, Jorge A. Zavala, the THRILS collaboration. 2025-12-14. THRILS -- The High-(Redshift+Ionization) Line Search: Program Description & Redshift Catalog. https://arxiv.org/abs/2512.12509

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