Discovery of the Fastest Early Optical Emission from Overluminous SN Ia 2020hvf: A Thermonuclear Explosion within a Dense Circumstellar Environment

Jiang, Ji-an; Maeda, Keiichi; Kawabata, Miho; Doi, Mamoru; Shigeyama, Toshikazu; Tanaka, Masaomi; Tominaga, Nozomu; Nomoto, Ken’ichi; Niino, Yuu; Sako, Shigeyuki; Ohsawa, Ryou; Schramm, Malte; Yamanaka, Masahito; Kobayashi, Naoto; Takahashi, H.; Nakaoka, Tatsuya; Kawabata, Koji S.; Isogai, Keisuke; Aoki, Tsutomu; Kondo, Sohei; Mori, Yuki; Arimatsu, Ko; Kasuga, Toshihiro; Okumura, Shin-ichiro; Urakawa, Seitaro; Reichart, D.; Taguchi, Kenta; Arima, Noriaki; Beniyama, Jin; Uno, Kazuo; Hamada, Taisei

doi:10.3847/2041-8213/ac375f

Cited by 38 publications

(85 citation statements)

References 90 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The cause of the early-time light-curve diversity is unknown, but various effects have been proposed. These include: (1) the collision of the ejecta with a companion star in a single degenerate system (Marietta et al 2000;Kasen 2010); (2) the presence of 56 Ni in the outer layer, which can be mixed out from the center of the explosion or produced in situ (Piro & Morozova 2016;Ni et al 2022); or (3) the interaction of the ejecta with circumstellar material (Gerardy et al 2007;Dragulin & Hoeflich 2016;Piro & Morozova 2016;Jiang et al 2021).…”

Section: Introductionmentioning

confidence: 99%

A Speed Bump: SN 2021aefx Shows that Doppler Shift Alone Can Explain Early Excess Blue Flux in Some Type Ia Supernovae

Ashall

Lü

Shappee

et al. 2022

ApJL

View full text Add to dashboard Cite

We present early-time photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2021aefx. The early-time u-band light curve shows an excess flux when compared to normal SNe Ia. We suggest that the early excess blue flux may be due to a rapid change in spectral velocity in the first few days post explosion, produced by the emission of the Ca ii H&K feature passing from the u to the B bands on the timescale of a few days. This effect could be dominant for all SNe Ia that have broad absorption features and early-time velocities over 25,000 km s−1. It is likely to be one of the main causes of early excess u-band flux in SNe Ia that have early-time high velocities. This effect may also be dominant in the UV filters, as well as in places where the SN spectral energy distribution is quickly rising to longer wavelengths. The rapid change in velocity can only produce a monotonic change (in flux-space) in the u band. For objects that explode at lower velocities, and have a more structured shape in the early excess emission, there must also be an additional parameter producing the early-time diversity. More early-time observations, in particular early spectra, are required to determine how prominent this effect is within SNe Ia.

show abstract

Section: Introductionmentioning

confidence: 99%

A Speed Bump: SN 2021aefx Shows that Doppler Shift Alone Can Explain Early Excess Blue Flux in Some Type Ia Supernovae

Ashall

Lü

Shappee

et al. 2022

ApJL

View full text Add to dashboard Cite

show abstract

“…In a handful of cases, a flux excess in the early light curves of SNe Ia has been detected (commonly referred to as 'bump' or 'flash') e.g. SN 2012cg (Marion et al 2016), SN 2014J (Goobar et al 2015), iPTF14atg (Cao et al 2015), SN 2016jhr (Jiang et al 2017), SN 2017cbv (Hosseinzadeh et al 2017), SN 2018oh (Dimitriadis et al 2019;Shappee et al 2019;Li et al 2019), SN 2019yvq (Miller et al 2020a), SN 2020hvf (Jiang et al 2021), andSN 2021hpr (Lim et al, in prep.). Olling et al (2015) analysed a sample of three SNe Ia with extremely high cadence Kepler light curves, and found no evidence of flux excesses at early times in these events.…”

mentioning

confidence: 99%

Constraining Type Ia supernova explosions and early flux excesses with the Zwicky Transient Factory

Deckers,

Maguire,

Magee

et al. 2022

Preprint

View full text Add to dashboard Cite

In the new era of time-domain surveys Type Ia supernovae are being caught sooner after explosion, which has exposed significant variation in their early light curves. Two driving factors for early time evolution are the distribution of 56 Ni in the ejecta and the presence of flux excesses of various causes. We perform an analysis of the largest young SN Ia sample to date. We compare 115 SN Ia light curves from the Zwicky Transient Facility to the model grid containing light curves of Chandrasekhar-mass explosions with a range of 56 Ni masses, 56 Ni distributions and explosion energies. We find that the majority of our observed light curves are well reproduced by Chandrasekhar-mass explosion models with a preference for highly extended 56 Ni distributions. We identify six SNe Ia with an early-time flux excess in our gr-band data (four 'blue' and two 'red' flux excesses). We find an intrinsic rate of 18±11 per cent of early flux excesses in SNe Ia at z < 0.07, based on three detected flux excesses out of 30 (10 per cent) observed SNe Ia with a simulated efficiency of 57 per cent. This is comparable to rates of flux excesses in the literature but also accounts for detection efficiencies. Two of these events are mostly consistent with CSM interaction, while the other four have longer lifetimes in agreement with companion interaction and 56 Ni-clump models. We find a higher frequency of flux excesses in 91T/99aa-like events (44±13 per cent).

show abstract

“…Deckers et al (2022) also find that SNe Ia with early flux excess originate from younger stellar populations. This, and the early flux excess in some super-Chandrasekhar SNe Ia (e.g., SN 2020hvf; Jiang et al 2021), might suggest that some early flux excess SNe Ia come from the CD scenario. The CD scenario can account for super-Chandrasekhar SNe Ia and can explain a short CEE to explosion delay time (t CEED ; Soker 2022).…”

Section: Discussion and Summarymentioning

confidence: 95%

Pre-explosion helium shell flash in type Ia supernovae

Soker

2022

Preprint

View full text Add to dashboard Cite

I study the possibility that within the frame of the core degenerate (CD) scenario for type Ia supernovae (SNe Ia) the merger process of the core of the asymptotic giant branch (AGB) star and the white dwarf (WD) maintains an envelope mass of ≈ 0.03M ⊙ that causes a later helium shell flash. I estimate the number of pre-explosion helium shell flash events to be less than few per cents of all CD scenario SNe Ia. A helium shell flash while the star moves to the left on the HR diagram as a post-AGB star (late thermal pulse-LTP) or along the WD cooling track (very-LTP) causes the star to expand and become a 'born again' AGB star. Merger remnants exploding while still on the AGB form peculiar SNe Ia or peculiar SNe II (if hydrogen is detected), while an explosion inside an inflated born-again star results in an early flux excess in the light curve of the SN Ia. The fraction of systems that might show an early flux excess due to LTP/VLTP is < few × 10 −4 of all SNe Ia, much below the observed fraction. In the frame of the CD scenario SNe Ia with early flux excess result from SN ejecta collision with planetary nebula fallback gas, or from mixing of 56 Ni to the outer regions of the SN ejecta. Ongoing sky surveys might find about one case per year where LTP/VLTP influences the SN light curve.

show abstract

Discovery of the Fastest Early Optical Emission from Overluminous SN Ia 2020hvf: A Thermonuclear Explosion within a Dense Circumstellar Environment

Cited by 38 publications

References 90 publications

A Speed Bump: SN 2021aefx Shows that Doppler Shift Alone Can Explain Early Excess Blue Flux in Some Type Ia Supernovae

A Speed Bump: SN 2021aefx Shows that Doppler Shift Alone Can Explain Early Excess Blue Flux in Some Type Ia Supernovae

Constraining Type Ia supernova explosions and early flux excesses with the Zwicky Transient Factory

Pre-explosion helium shell flash in type Ia supernovae

Contact Info

Product

Resources

About