The ANDICAM-SOFI Near-infrared and Optical type Ia Supernova (ASNOS) sample: Description and data release

¹ Institut d’Estudis Espacials de Catalunya (IEEC), 08034 Barcelona, Spain
² Institute of Space Sciences (ICE, CSIC), Campus UAB, Carrer de Can Magrans s/n, 08193 Barcelona, Spain
³ School of Physics, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
⁴ Instituto de Ciencias Exactas y Naturales (ICEN), Universidad Arturo Prat, Chile
⁵ Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
⁶ Observatories of the Carnegie Institution for Science, 813 Santa Barbara St, Pasadena, CA 91101, USA
⁷ Institute for Astronomy, University of Hawai ’i at Manoa, 2680 Woodlawn Drive, Hawai ’i, HI 96822, USA
⁸ Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova, 10691 Stockholm, Sweden
⁹ European Southern Observatory, Alonso de Crdova 3107, Casilla 19 Santiago, Chile
¹⁰ Institute for Astronomy, University of Hawaii, 2680 Woodlawn Dr., Honolulu, HI 96825, USA
¹¹ Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warszawa, Poland
¹² Graduate Institute of Astronomy, National Central University, 300 Jhongda Road, 32001 Jhongli, Taiwan

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Received: 26 June 2025
Accepted: 27 November 2025

Abstract

Type Ia supernovae (SNe Ia) provide the robustest means of measuring extragalactic distances. While increasing the number of SNe Ia observed in the optical has received most effort so far, near-infrared (NIR) observations remain scarce despite their advantages. The dust extinction in NIR observations is lower and the behavior of standard candles is more intrinsic and therefore requires little to no empirical corrections. We present the ANDICAM-SOFI Near-infrared and Optical type Ia Supernova (ASNOS) dataset with sample size of 1482 epochs in the BVRIYJH filters from the ANDICAM instrument on the 1.3-meter SMARTS telescope at Cerro Tololo Inter-American Observatory, along with 125 JHK epochs from the SOFI instrument on the 3.58-meter New Technology Telescope on the La Silla Observatory. Additionally, we incorporate optical forced photometry from the Zwicky Transient Facility and the Asteroid Terrestrial-impact Last Alert System. The sample comprises 41 SNe Ia in total, including 29 normal events, eight 1991T-like objects, and four peculiar subtypes, all located at redshifts z<0.085. We provide a detailed overview of the ASNOS sample selection, data reduction, SN photometry, construction of the global and local host-galaxy spectral energy distribution, and SN light-curve fitting using three methods: SALT3-NIR, SNooPy, and BayeSN. A companion paper will present the cosmological analysis.