Abstract
We present optical, infrared, ultraviolet, and radio observations of SN 2022xkq, an underluminous fast-declining Type Ia supernova (SN Ia) in NGC 1784 (D ≈ 31 Mpc), from <1 to 180 days after explosion. The high-cadence observations of SN 2022xkq, a photometrically transitional and spectroscopically 91bg-like SN Ia, cover the first days and weeks following explosion, which are critical to distinguishing between explosion scenarios. The early light curve of SN 2022xkq has a red early color and exhibits a flux excess that is more prominent in redder bands; this is the first time such a feature has been seen in a transitional/91bg-like SN Ia. We also present 92 optical and 19 near-infrared (NIR) spectra, beginning 0.4 days after explosion in the optical and 2.6 days after explosion in the NIR. SN 2022xkq exhibits a long-lived C i 1.0693 μm feature that persists until 5 days post-maximum. We also detect C ii λ6580 in the pre-maximum optical spectra. These lines are evidence for unburnt carbon that is difficult to reconcile with the double detonation of a sub-Chandrasekhar mass white dwarf. No existing explosion model can fully explain the photometric and spectroscopic data set of SN 2022xkq, but the considerable breadth of the observations is ideal for furthering our understanding of the processes that produce faint SNe Ia.
| Original language | English (US) |
|---|---|
| Article number | 29 |
| Journal | Astrophysical Journal |
| Volume | 960 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2024 |
Funding
L.G. acknowledges financial support from the Spanish Ministerio de Ciencia e Innovación (MCIN), the Agencia Estatal de Investigación (AEI) 10.13039/501100011033, and the European Social Fund (ESF) “Investing in your future” under the 2019 Ramón y Cajal program RYC2019-027683-I and the PID2020-115253GA-I00 HOSTFLOWS project; from Centro Superior de Investigaciones Científicas (CSIC) under the PIE project 20215AT016; and from the program Unidad de Excelencia María de Maeztu CEX2020-001058-M. Research by Y.D., S.V., N.M.R, E.H., and D.M. is supported by NSF grant AST-2008108. L.C. is grateful for support from NSF grants AST-2107070 and AST-2205628. No current publicly available model can explain the early color and light curve, the spectroscopic evolution, and the strength of the carbon features of SN 2022xkq all at once. Given the breadth of the observational record available, this SN offers the unique opportunity to rigorously test progenitor scenarios. SN 2022xkq will be an important reference point in our efforts to understand the progenitors and explosions of underluminous SNe Ia. Acknowledgments which is funded by the Australian Government for operation as a National Facility managed by CSIRO. We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The ATCA data reported here were obtained under Program C1473 (P.I. S. Ryder). M.N. is supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 948381) and by UK Space Agency grant No. ST/Y000692/1. This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for near-Earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; by-products of the NEO search include images and catalogs from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112, HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen’s University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and the Millennium Institute of Astrophysics (MAS), Chile. C.L. acknowledges support from the National Science Foundation Graduate Research Fellowship under grant No. DGE-2233066. L.A.K. acknowledges support by NASA FINESST fellowship 80NSSC22K1599. Time-domain research by the University of Arizona team, J.P., and D.J.S. is supported by NSF grants AST-1821987, 1813466, 1908972, 2108032, and 2308181 and by the Heising-Simons Foundation under grant No. 2020-1864. 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 and William and Marina Kast. Research at Lick Observatory is partially supported by a generous gift from Google. P.L. acknowledges support from the Swedish Research Council. This paper uses observations made with the MuSCAT3 instrument, developed by the Astrobiology Center and under financial supports by JSPS KAKENHI (JP18H05439) and JST PRESTO (JPMJPR1775), at Faulkes Telescope North on Maui, HI, operated by the Las Cumbres Observatory. The Keck Infrared Transient Survey was executed primarily by members of the UC Santa Cruz transients team, who were supported in part by NASA grants NNG17PX03C, 80NSSC21K2076, 80NSSC22K1513, and 80NSSC22K1518; by NSF grant AST–1911206; and by fellowships from the Alfred P. Sloan Foundation and the David and Lucile Packard Foundation to R.J.F. KITS was directly supported by NASA grant 80NSSC23K0301. This publication was made possible through the support of an LSSTC Catalyst Fellowship to K.A.B., funded through grant 62192 from the John Templeton Foundation to LSST Corporation. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of LSSTC or the John Templeton Foundation. M.M. acknowledges support in part from ADAP program grant No. 80NSSC22K0486, from the NSF AST-2206657, and from the HST GO program HST-GO-16656. S.B.'s work was supported by the “Programme National de Physique Stellaire” (PNPS) of CNRS/INSU, co-funded by CEA and CNES, and has made use of computing facilities operated by CeSAM data center at LAM, Marseille, France. The Las Cumbres Observatory group is supported by NSF grants AST-1911151 and AST-1911225. This work was funded in part by ANID, Millennium Science Initiative, ICN12_009. Y.-Z.C. is supported by the National Natural Science Foundation of China (NSFC, grant No. 12303054) and the International Centre of Supernovae, Yunnan Key Laboratory (No. 202302AN360001). This work was performed in part at the Aspen Center for Physics, which is supported by National Science Foundation grant PHY-2210452. The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation Members are: the University of Arizona on behalf of the Arizona Board of Regents; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Leibniz Institute for Astrophysics Potsdam, and Heidelberg University; The Ohio State University; and the Research Corporation, on behalf of the University of Notre Dame, University of Minnesota, and University of Virginia. This paper made use of the modsCCDRed data reduction code developed in part with funds provided by NSF grants AST-9987045 and AST-1108693. I.S. is supported by funding from the Italian Ministry of Education, University and Research (MIUR), PRIN 2017 (grant 20179ZF5KS), and PRIN-INAF 2022 project “Shedding light on the nature of gap transients: from the observations to the models” and acknowledges the support of the doctoral grant funded by Istituto Nazionale di Astrofisica via the University of Padova and MIUR.
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science