Abstract
We present panchromatic observations and modeling of calcium-strong supernovae (SNe) 2021gno in the star-forming host-galaxy NGC 4165 and 2021inl in the outskirts of elliptical galaxy NGC 4923, both monitored through the Young Supernova Experiment transient survey. The light curves of both, SNe show two peaks, the former peak being derived from shock cooling emission (SCE) and/or shock interaction with circumstellar material (CSM). The primary peak in SN 2021gno is coincident with luminous, rapidly decaying X-ray emission (L x = 5 × 1041 erg s-1) detected by Swift-XRT at δ t = 1 day after explosion, this observation being the second-ever detection of X-rays from a calcium-strong transient. We interpret the X-ray emission in the context of shock interaction with CSM that extends to r < 3 × 1014 cm. Based on X-ray modeling, we calculate a CSM mass M CSM = (0.3-1.6) × 10-3 M ⊙ and density n = (1-4) × 1010 cm-3. Radio nondetections indicate a low-density environment at larger radii (r > 1016 cm) and mass-loss rate of Ṁ<10-4 M ⊙ yr-1. SCE modeling of both primary light-curve peaks indicates an extended-progenitor envelope mass M e = 0.02-0.05 M ⊙ and radius R e = 30-230 R ⊙. The explosion properties suggest progenitor systems containing either a low-mass massive star or a white dwarf (WD), the former being unlikely given the lack of local star formation. Furthermore, the environments of both SNe are consistent with low-mass hybrid He/C/O WD + C/O WD mergers.
| Original language | English (US) |
|---|---|
| Article number | 58 |
| Journal | Astrophysical Journal |
| Volume | 932 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jun 1 2022 |
Funding
W.J.-G. is supported by the National Science Foundation Graduate Research Fellowship Program under grant No. DGE-1842165. W.J.-G. acknowledges support through NASA grants in support of Hubble Space Telescope program GO-16075 and 16500. This research was supported in part by the National Science Foundation under grant No. NSF PHY-1748958. R.M. acknowledges support by the National Science Foundation under Award No. AST-1909796 and AST-1944985. R.M. is a CIFAR Azrieli Global Scholar in the Gravity & the Extreme Universe Program, 2019. The Margutti’s team at Northwestern and UC Berkeley is partially funded by the Heising-Simons Foundation under grant #2018-0911 and #2021-3248 (PI: Margutti). Based in part on observations obtained with the Samuel Oschin 48 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project, ZTF is supported by the NSF under grant AST-1440341 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, the University of Washington, Deutsches Elektronen-Synchrotron and Humboldt University, Los Alamos National Laboratories, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, and the Lawrence Berkeley National Laboratory. Operations are conducted by the Caltech Optical Observatories (COO), the Infrared Processing and Analysis Center (IPAC), and the University of Washington (UW). A major upgrade of the Kast spectrograph on the Shane 3 m telescope at Lick Observatory was made possible through generous gifts from the Heising-Simons Foundation as well as William and Marina Kast. Research at Lick Observatory is partially supported by a generous gift from Google. The UCSC team is supported in part by NASA grant 80NSSC20K0953, NSF grant AST-1815935, the Gordon & Betty Moore Foundation, the Heising-Simons Foundation, and by a fellowship from the David and Lucile Packard Foundation to R.J.F. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, STScI, NASA under grant NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, NSF grant AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation. W. M. Keck Observatory and MMT Observatory access was supported by Northwestern University and the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. V.A.V. acknowledges support by the National Science Foundation under Award No.AST-2108676. C.R.A. was supported by grants from VILLUM FONDEN (project numbers 16599 and 25501). Parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. The Young Supernova Experiment and its research infrastructure is supported by the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC grant agreement No. 101002652, PI K. Mandel), the Heising-Simons Foundation (2018-0913, PI R. Foley; 2018-0911, PI R. Margutti), NASA (NNG17PX03C, PI R. Foley), NSF (AST-1720756, AST-1815935, PI R. Foley; AST-1909796, AST-1944985, PI R. Margutti), the David & Lucille Packard Foundation (PI R. Foley), VILLUM FONDEN (project number 16599, PI J. Hjorth), and the Center for AstroPhysical Surveys (CAPS) at the National Center for Supercomputing Applications (NCSA) and the University of Illinois Urbana-Champaign.
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science