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Unprecedented Early Flux Excess in the Hybrid 02es-like Type Ia Supernova 2022ywc Indicates Interaction with Circumstellar Material

Authors :
Shubham Srivastav
T. Moore
M. Nicholl
M. R. Magee
S. J. Smartt
M. D. Fulton
S. A. Sim
J. M. Pollin
L. Galbany
C. Inserra
A. Kozyreva
Takashi J. Moriya
F. P. Callan
X. Sheng
K. W. Smith
J. S. Sommer
J. P. Anderson
M. Deckers
M. Gromadzki
T. E. Müller-Bravo
G. Pignata
A. Rest
D. R. Young
Source :
The Astrophysical Journal Letters, Vol 956, Iss 2, p L34 (2023)
Publication Year :
2023
Publisher :
IOP Publishing, 2023.

Abstract

We present optical photometric and spectroscopic observations of the 02es-like type Ia supernova (SN) 2022ywc. The transient occurred in the outskirts of an elliptical host galaxy and showed a striking double-peaked light curve with an early excess feature detected in the ATLAS orange and cyan bands. The early excess is remarkably luminous with an absolute magnitude ∼ − 19, comparable in luminosity to the subsequent radioactively driven second peak. The spectra resemble the hybrid 02es-like SN 2016jhr, which is considered to be a helium shell detonation candidate. We investigate different physical mechanisms that could power such a prominent early excess and rule out massive helium shell detonation, surface ^56 Ni distribution, and ejecta–companion interaction. We conclude that SN ejecta interacting with circumstellar material (CSM) is the most viable scenario. Semianalytical modeling with MOSFiT indicates that SN ejecta interacting with ∼0.05 M _⊙ of CSM at a distance of ∼10 ^14 cm can explain the extraordinary light curve. A double-degenerate scenario may explain the origin of the CSM, by tidally stripped material from either the secondary white dwarf or disk-originated matter launched along polar axes following the disruption and accretion of the secondary white dwarf. A nonspherical CSM configuration could suggest that a small fraction of 02es-like events viewed along a favorable line of sight may be expected to display a very conspicuous early excess like SN 2022ywc.

Details

Language :
English
ISSN :
20418213 and 20418205
Volume :
956
Issue :
2
Database :
Directory of Open Access Journals
Journal :
The Astrophysical Journal Letters
Publication Type :
Academic Journal
Accession number :
edsdoj.fc0161952c554de3a5563511b4151686
Document Type :
article
Full Text :
https://doi.org/10.3847/2041-8213/acffaf