SN 2022oqm: A Bright and Multi-peaked Calcium-rich Transient
Abstract
We present the photometric and spectroscopic evolution of SN 2022oqm, a nearby multi-peaked hydrogen- and helium-weak calcium-rich transient (CaRT). SN 2022oqm was detected 13.1 kpc from its host galaxy, the face-on spiral galaxy NGC 5875. Extensive spectroscopic coverage reveals an early hot (T >= 40,000 K) continuum and carbon features observed 1~day after discovery, SN Ic-like photospheric-phase spectra, and strong forbidden calcium emission starting 38 days after discovery. SN 2022oqm has a relatively high peak luminosity (MB = -17 mag) for (CaRTs), making it an outlier in the population. We determine that three power sources are necessary to explain the light curve (LC), with each corresponding to a distinct peak. The first peak is powered by an expanding blackbody with a power law luminosity, suggesting shock cooling by circumstellar material (CSM). Subsequent LC evolution is powered by a double radioactive decay model, consistent with two sources of photons diffusing through optically thick ejecta. From the LC, we derive an ejecta mass and 56Ni mass of ~0.6 solar masses and ~0.09 solar masses. Spectroscopic modeling suggests 0.6 solar masses of ejecta, and with well-mixed Fe-peak elements throughout. We discuss several physical origins for SN 2022oqm and find either a surprisingly massive white dwarf progenitor or a peculiar stripped envelope model could explain SN 2022oqm. A stripped envelope explosion inside a dense, hydrogen- and helium-poor CSM, akin to SNe Icn, but with a large 56Ni mass and small CSM mass could explain SN 2022oqm. Alternatively, helium detonation on an unexpectedly massive white dwarf could also explain SN 2022oqm.
Keywords
Cite
@article{arxiv.2308.12991,
title = {SN 2022oqm: A Bright and Multi-peaked Calcium-rich Transient},
author = {S. Karthik Yadavalli and V. Ashley Villar and Luca Izzo and Yossef Zenati and Ryan J. Foley and J. Craig Wheeler and Charlotte R. Angus and Dominik Bánhidi and Katie Auchettl and Barna Imre Bíró and Attila Bódi and Zsófia Bodola and Thomas de Boer and Kenneth C. Chambers and Ryan Chornock and David A. Coulter and István Csányi and Borbála Cseh and Srujan Dandu and Kyle W. Davis and Connor Braden Dickinson and Diego Farias and Joseph Farah and Christa Gall and Hua Gao and D. Andrew Howell and Wynn V. Jacobson-Galan and Nandita Khetan and Charles D. Kilpatrick and Réka Könyves-Tóth and Levente Kriskovics and Natalie LeBaron and Kayla Loertscher and X. K. Le Saux and Rafaella Margutti and Eugene A. Magnier and Curtis McCully and Peter McGill and Hao-Yu Miao and Megan Newsome and Estefania Padilla Gonzalez and András Pál and Boróka H. Pál and Yen-Chen Pan and Collin A. Politsch and Conor L. Ransome and Enrico Ramirez-Ruiz and Armin Rest and Sofia Rest and Olivia Robinson and Huei Sears and Jackson Scheer and Ádám Sódor and Jonathan Swift and Péter Székely and Róbert Szakáts and Tamás Szalai and Kirsty Taggart and Giacomo Terreran and Padma Venkatraman and József Vinkó and Grace Yang and Henry Zhou},
journal= {arXiv preprint arXiv:2308.12991},
year = {2024}
}
Comments
35 pages, 17 figures, 7 tables, Accepted for Publication in ApJ