The NIRISS PASSAGE Spectroscopic Redshift Catalog in COSMOS

June 2026 • 2026ApJS..284...64H

Authors • Huberty, Mason S. • Nedkova, Kalina V. • Sattari, Zahra • Mehta, Vihang • Scarlata, Claudia • Rafelski, Marc • Hayes, Matthew J. • Watson, Peter J. • Acharyya, Ayan • Levine, Jacob • Vulcani, Benedetta • Le Reste, Alexandra • Hasan, Farhanul • Colbert, James • Trenti, Michele • Wang, Xin • Runnholm, Axel • Malkan, Matthew A. • Bunker, Andrew J. • Alavi, Anahita • Atek, Hakim • Battisti, Andrew J. • Dai, Y. Sophia • Kim, Keunho • Henry, Alaina • Rutkowski, Michael J. • Akins, Hollis • Casey, Caitlin M. • Franco, Maximilien • Harish, Santosh • Kartaltepe, Jeyhan S. • Koekemoer, Anton • Liu, Daizhong • McCracken, Henry • Rhodes, Jason • Robertson, Brant • Shuntov, Marko

Abstract • We present the Parallel Application of Slitless Spectroscopy to Analyze Galaxy Evolution (PASSAGE) spectroscopic redshift catalog in the COSMOS field. PASSAGE is a JWST Cycle 1 Near Infrared Imager and Slitless Spectrograph (or NIRISS) wide-field slitless spectroscopy pure-parallel survey, obtaining near-infrared spectra of thousands of extragalactic sources. Fifteen out of 63 PASSAGE fields fall within the Hubble Space Telescope COSMOS footprint, of which 11 overlap with COSMOS-Web, a JWST treasury survey providing additional space-based photometry. We present our custom line-finding algorithm and visual inspection effort used to identify emission lines and derive the spectroscopic redshifts for line-emitting sources in PASSAGE. The line-finding algorithm identifies between ∼200 and 950 line-emitting candidates per field, of which typically 47% were identified as true emission lines post visual inspection. We identify 2183 emission-line sources at 0.08 ≲ z ≲ 4.7, 1896 of which have available COSMOS photometric redshifts. We find excellent redshift agreement between the COSMOS photometric redshifts and the PASSAGE spectroscopic redshifts for strong (signal-to-noise ratio > 5), multi-line-emitting sources. This agreement weakens for PASSAGE single-line emitters with ambiguous identities. These single-line emitters are likely misidentified around 18% of the time based on comparisons to photometric redshifts. We derive stellar masses using PASSAGE photometry and spectroscopic redshifts, in broad agreement with existing COSMOS-Web stellar masses, but with some discrepancy driven by redshift disagreements. We publicly release this spectroscopic redshift catalog, which will enable community-led science in prime extragalactic fields and serve as a crucial dataset for validating Euclid and Roman spectroscopy.

Links

• PDF https://iopscience.iop.org/article/10.3847/1538-4365/ae6777/pdf
• PREPRINT http://arxiv.org/abs/2601.02220
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2026ApJS..284...64H
• DATA https://doi.org/10.17909/6ca5-ba17
• ELECTR https://doi.org/10.3847/1538-4365/ae6777