SN 2018is: A low-luminosity Type IIP supernova with narrow hydrogen emission lines at early phases
Year: 2025
Type: article
Abstract: We present a comprehensive photometric and spectroscopic study of the Type IIP supernova (SN) 2018is. The V band luminosity and the expansion velocity at 50 days post-explosion are −15.1 ± 0.2 mag (corrected for AV = 1.34 mag) and 1400 km s−1, classifying it as a low-luminosity SN II. The recombination phase in the V band is shorter, lasting around 110 days, and exhibits a steeper decline (1.0 mag per 100 days) compared to most other low-luminosity SNe II. Additionally, the optical and near-infrared spectra display hydrogen emission lines that are strikingly narrow, even for this class. The Fe II and Sc II line velocities are at the lower end of the typical range for low-luminosity SNe II. Semi-analytical modelling of the bolometric light curve suggests an ejecta mass of ∼8 M⊙, corresponding to a pre-supernova mass of ∼9.5 M⊙, and an explosion energy of ∼0.40 × 1051 erg. Hydrodynamical modelling further indicates that the progenitor had a zero-age main sequence mass of 9 M⊙, coupled with a low explosion energy of 0.19 × 1051 erg. The nebular spectrum reveals weak [O I] λλ6300,6364 lines, consistent with a moderate-mass progenitor, while features typical of Fe core-collapse events, such as He I, [C I], and Fe I, are indiscernible. However, the redder colours and low ratio of Ni to Fe abundance do not support an electron-capture scenario either. As a low-luminosity SN II with an atypically steep decline during the photospheric phase and remarkably narrow emission lines, SN 2018is contributes to the diversity observed within this population.
Authors: R. Dastidar, K. Misra, S. Valenti, D. J. Sand, A. Pastorello, A. Reguitti, G. Pignata, S. Benetti, S. Bose, A. Gangopadhyay, M. Singh, L. Tomasella, J. E. Andrews, I. Arcavi, C. Ashall, C. Bilinski, K. A. Bostroem, D. A. H. Buckley, G. Cannizzaro, L. Chomiuk, E. Congiu, S. Dong, Y. Dong, N. Elias-Rosa, M. Fraser, C. Gall, M. Gromadzki, D. Hiramatsu, G. Hosseinzadeh, D. A. Howell, E. Y. Hsiao, C. McCully, N. Smith, J. Strader
Institutions: Millennium Institute of Astrophysics, Aryabhatta Research Institute of Observational Sciences, University of California, Davis, University of Arizona, Osservatorio Astronomico di Padova, National Institute for Astrophysics, Brera Astronomical Observatory, University of Tarapacá, Aarhus University, Stockholm University, AlbaNova, Indian Institute of Astrophysics, International Gemini Observatory, Canadian Institute for Advanced Research, Tel Aviv University, University of Hawaiʻi at Mānoa, Virginia Tech, Michigan State University, European Southern Observatory, University College Dublin, University of Copenhagen, University of Warsaw, Center for Astrophysics Harvard & Smithsonian, The NSF AI Institute for Artificial Intelligence and Fundamental Interactions, Florida State University, University of California, Santa Barbara, University of California San Diego
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, Smithsonian Institution, National Aeronautics and Space Administration, Arthritis National Research Foundation, California Institute of Technology, Michigan State University, Agenția Națională pentru Cercetare și Dezvoltare, National Research Foundation, Department of Science and Technology, Ministry of Science and Technology, India, Indo-US Science and Technology Forum, Ministério da Ciência, Tecnologia e Inovação, Liverpool John Moores University, Agencia Nacional de Investigación y Desarrollo, Instituto de Astrofísica de Canarias, Jet Propulsion Laboratory, College of Engineering, Michigan State University, University of California, Davis, University of North Carolina at Chapel Hill, Science and Technology Facilities Council, Science and Engineering Research Board, INAF-Osservatorio Astronomico di Padova, CHIST-ERA
Awards: Collaborative Research: Studying Nearby Cosmic Explosions from their Earliest Moments, WoU-MMA: An Integrated Time Domain System for Discovery and Fast Follow-up of Gravitational Wave Events and Other Transients, Collaborative Research: The Multimessenger Treasure TROVE, a Tool for Rapid Object Vetting and Examination, Collaborative Research: WoU-MMA: Searches After Gravitational-waves Using Arizona's Observatories (SAGUARO), Constraining Type Ia Supernova Progenitors via their Environments, G4229062145, Speeding up the messenger: immediate detection of multimessenger transients with Las Cumbres Observatory, G486703439, G4923767615, CONSTRAINING SUPERNOVA PROGENITOR AND EXPLOSION PROPERTIES THROUGH LIGHT CURVE AND SPECTRAL MODELING OF A SAMPLE OF NEARBY SUPERNOVAE, G57481727, Collaborative Research: Automated Search and Follow-Up of Electromagnetic Counterparts to Gravitational-Wave Events in O4, G6584649838, G722162065, SOCAVACION EN TORNO A PILAS FUNDADAS EN LECHOS DE GRANULOMETRIA GRADUADA, G8800171866, Collaborative Research: Charting the Supernova-Gas-Stars Connection via a Major New VLA Survey of the Local Group, Revealing Supernova Progenitors with Las Cumbres Observatory
OpenAlex ID: W7122621945
FWCI:
Cites:
Cited by:
Related to: