The Keck Infrared Transient Survey was executed primarily by members of the UC Santa Cruz transients team, who were supported in part by NASA grants NNG17PX03C, 80NSSC21K2076z, 80NSSC22K1513, 80NSSC22K1518; NSF grant AST–1911206; and by fellowships from the Alfred P. Sloan Foundation and the David and Lucile Packard Foundation to R.J.F. KITS was directly supported by NASA grant 80NSSC23K0301. C.D.K. is partly supported by a CIERA postdoctoral fellowship. S.T. was supported by the Cambridge Centre for Doctoral Training in Data-Intensive Science funded by STFC. Support for J.R.P. was provided through NASA Hubble Fellowship grant HF2-51541.001-A, awarded by the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. L.G. acknowledges financial support from the Spanish Ministerio de Ciencia e Innovación (MCIN), the Agencia Estatal de Investigación (AEI) 10.13039/501100011033, and the European Social Fund (ESF) "Investing in your future" under the 2019 Ramón y Cajal program RYC2019-027683-I and the PID2020-115253GA-I00 HOSTFLOWS project, from Centro Superior de Investigaciones Científicas (CSIC) under the PIE project 20215AT016, and the program Unidad de Excelencia María de Maeztu CEX2020-001058-M. C.L. acknowledges support from the National Science Foundation (NSF) Graduate Research Fellowship under grant DGE-2233066. M.R.S. is supported by an STScI Postdoctoral Fellowship. A.V.F. is grateful for financial support from the Christopher R. Redlich Fund and many other donors. W.J.-G. is supported by the National Science Foundation Graduate Research Fellowship Program under grant DGE-1842165. W.J.-G. acknowledges support through NASA Hubble Space Telescope programs GO-16075 and GO-16500. J.S.B. acknowledges support from the Gordon and Betty Moore Foundation. S.M.W. was supported by the UK Science and Technology Facilities Council (STFC). This work was supported in part by the Director, Office of Science, Office of High Energy Physics of the U.S. Department of Energy under Contract DE-AC02-05CH11231. K.S.M. and M.G. acknowledge funding from the European Union's Horizon 2020 research and innovation programme under ERC grant Agreement 101002652. The LCO group is supported by NSF grant AST-1911225.

We present the Keck Infrared Transient Survey, a NASA Key Strategic Mission Support program to obtain near-infrared (NIR) spectra of astrophysical transients of all types, and its first data release, consisting of 105 NIR spectra of 50 transients. Such a data set is essential as we enter a new era of IR astronomy with the James Webb Space Telescope (JWST) and the upcoming Nancy Grace Roman Space Telescope (Roman). NIR spectral templates will be essential to search JWST images for stellar explosions of the first stars and to plan an effective Roman SN Ia cosmology survey, both key science objectives for mission success. Between 2022 February and 2023 July, we systematically obtained 274 NIR spectra of 146 astronomical transients, representing a significant increase in the number of available NIR spectra in the literature. Here, we describe the first release of data from the 2022A semester. We systematically observed three samples: a flux-limited sample that includes all transients <17 mag in a red optical band (usually ZTF r or ATLAS o bands); a volume-limited sample including all transients within redshift z < 0.01 (D ≈ 50 Mpc); and an SN Ia sample targeting objects at phases and light-curve parameters that had scant existing NIR data in the literature. The flux-limited sample is 39% complete (60% excluding SNe Ia), while the volume-limited sample is 54% complete and is 79% complete to z = 0.005. Transient classes observed include common Type Ia and core-collapse supernovae, tidal disruption events, luminous red novae, and the newly categorized hydrogen-free/helium-poor interacting Type Icn supernovae. We describe our observing procedures and data reduction using PypeIt, which requires minimal human interaction to ensure reproducibility.

With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2020-001058-M).

Peer reviewed