_version_ 1866917927772487680
author Dastidar, R.
Misra, K.
Valenti, S.
Sand, D. J.
Pastorello, A.
Reguitti, A.
Pignata, G.
Benetti, S.
Bose, S.
Gangopadhyay, A.
Singh, M.
Tomasella, L.
Andrews, J. E.
Arcavi, I.
Ashall, C.
Bilinski, C.
Bostroem, K. A.
Buckley, D. A. H.
Cannizzaro, G.
Chomiuk, L.
Congiu, E.
Dong, S.
Dong, Y.
Elias-Rosa, N.
Fraser, M.
Gall, C.
Gromadzki, M.
Hiramatsu, D.
Hosseinzadeh, G.
Howell, D. A.
Hsiao, E. Y.
McCully, C.
Smith, N.
Strader, J.
author_facet Dastidar, R.
Misra, K.
Valenti, S.
Sand, D. J.
Pastorello, A.
Reguitti, A.
Pignata, G.
Benetti, S.
Bose, S.
Gangopadhyay, A.
Singh, M.
Tomasella, L.
Andrews, J. E.
Arcavi, I.
Ashall, C.
Bilinski, C.
Bostroem, K. A.
Buckley, D. A. H.
Cannizzaro, G.
Chomiuk, L.
Congiu, E.
Dong, S.
Dong, Y.
Elias-Rosa, N.
Fraser, M.
Gall, C.
Gromadzki, M.
Hiramatsu, D.
Hosseinzadeh, G.
Howell, D. A.
Hsiao, E. Y.
McCully, C.
Smith, N.
Strader, J.
contents We present a comprehensive photometric and spectroscopic study of the Type IIP SN 2018is. The $V$-band luminosity and the expansion velocity at 50 days post-explosion are $-$15.1$\pm$0.2 mag (corrected for A$_V$=1.34 mag) and 1400 km s$^{-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 $\sim$8 M$_\odot$, corresponding to a pre-supernova mass of $\sim$9.5 M$_\odot$, and an explosion energy of $\sim$0.40 $\times$ 10$^{51}$ erg. Hydrodynamical modelling further indicates that the progenitor had a zero-age main sequence mass of 9 M$_\odot$, coupled with a low explosion energy of 0.19 $\times$ 10$^{51}$ erg. The nebular spectrum reveals weak [O I] $λλ$6300,6364 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.
format Preprint
id arxiv_https___arxiv_org_abs_2501_01530
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle SN 2018is: a low-luminosity Type IIP supernova with narrow hydrogen emission lines at early phases
Dastidar, R.
Misra, K.
Valenti, S.
Sand, D. J.
Pastorello, A.
Reguitti, A.
Pignata, G.
Benetti, S.
Bose, S.
Gangopadhyay, A.
Singh, M.
Tomasella, L.
Andrews, J. E.
Arcavi, I.
Ashall, C.
Bilinski, C.
Bostroem, K. A.
Buckley, D. A. H.
Cannizzaro, G.
Chomiuk, L.
Congiu, E.
Dong, S.
Dong, Y.
Elias-Rosa, N.
Fraser, M.
Gall, C.
Gromadzki, M.
Hiramatsu, D.
Hosseinzadeh, G.
Howell, D. A.
Hsiao, E. Y.
McCully, C.
Smith, N.
Strader, J.
High Energy Astrophysical Phenomena
We present a comprehensive photometric and spectroscopic study of the Type IIP SN 2018is. The $V$-band luminosity and the expansion velocity at 50 days post-explosion are $-$15.1$\pm$0.2 mag (corrected for A$_V$=1.34 mag) and 1400 km s$^{-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 $\sim$8 M$_\odot$, corresponding to a pre-supernova mass of $\sim$9.5 M$_\odot$, and an explosion energy of $\sim$0.40 $\times$ 10$^{51}$ erg. Hydrodynamical modelling further indicates that the progenitor had a zero-age main sequence mass of 9 M$_\odot$, coupled with a low explosion energy of 0.19 $\times$ 10$^{51}$ erg. The nebular spectrum reveals weak [O I] $λλ$6300,6364 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.
title SN 2018is: a low-luminosity Type IIP supernova with narrow hydrogen emission lines at early phases
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2501.01530