Pre-explosion Helium Shell Flash in Type Ia Supernovae

Soker, Noam

doi:10.1088/1674-4527/ac7d9e

Cited by 2 publications

(1 citation statement)

References 120 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The high mass loss rate phase shortly before explosion might be powered by a binary interaction that is triggered by the sudden expansion of the RSG star years to weeks before explosion (e.g., Soker 2013;Smith & Arnett 2014). 1 The binary interaction likely involves jets (e.g., a review by Soker 2022). A problem with this type of CSM is that there was no recorded outburst of the progenitor of SN 2023ixf.…”

Section: Introductionmentioning

confidence: 99%

A Pre-explosion Effervescent Zone for the Circumstellar Material in SN 2023ixf

Soker

2023

Res. Astron. Astrophys.

Self Cite

View full text Add to dashboard Cite

I present the effervescent zone model to account for the compact dense circumstellar material (CSM) around the progenitor of the core collapse supernova (CCSN) SN~2023ixf. The effervescent zone is composed of bound dense clumps that are lifted by stellar pulsation and envelope convection to distances of $\approx {\rm tens} \times \AU$, and then fall back. The dense clumps provide most of the compact CSM mass and exist alongside the regular (escaping) wind. I crudely estimate that for a compact CSM within $R_{\rm CSM} \approx 30 \AU$ that contains $M_{\rm CSM} \approx 0.01 M_\odot$, the density of each clump is $k_b \ga 3000$ times the density of the regular wind at the same radius and that the total volume filling factor of the clumps is several percent. The clumps might cover only a small fraction of the CCSN photosphere in the first days post-explosion, accounting for the lack of strong narrow absorption lines. The long-lived effervescent zone is compatible with no evidence for outbursts in the years prior to SN~2023ixf explosion and the large-amplitude pulsations of its progenitor, and it is an alternative to the CSM scenario of several-years-long high mass loss rate wind.

show abstract

Section: Introductionmentioning

confidence: 99%

A Pre-explosion Effervescent Zone for the Circumstellar Material in SN 2023ixf

Soker

2023

Res. Astron. Astrophys.

Self Cite

View full text Add to dashboard Cite

show abstract

Polarimetry of hydrogen-poor superluminous supernovae

Pursiainen¹,

G.²,

Cikota³

et al. 2023

A&A

View full text Add to dashboard Cite

We present linear polarimetry for seven hydrogen-poor superluminous supernovae (SLSNe-I) of which only one has previously published polarimetric data. The best-studied event is SN 2017gci, for which we present two epochs of spectropolarimetry at +3 d and +29 d post-peak in rest frame, accompanied by four epochs of imaging polarimetry up to +108 d. The spectropolarimetry at +3 d shows increasing polarisation degree P towards the redder wavelengths and exhibits signs of axial symmetry, but at +29 d, P ∼ 0 throughout the spectrum, implying that the photosphere of SN 2017gci evolved from a slightly aspherical configuration to a more spherical one in the first month post-peak. However, an increase of P to ∼0.5% at ∼ + 55 d accompanied by a different orientation of the axial symmetry compared to +3 d implies the presence of additional sources of polarisation at this phase. The increase in polarisation is possibly caused by interaction with circumstellar matter (CSM), as already suggested by a knee in the light curve and a possible detection of broad Hα emission at the same phase. We also analysed the sample of all 16 SLSNe-I with polarimetric measurements to date. The data taken during the early spectroscopic phase show consistently low polarisation, indicating at least nearly spherical photospheres. No clear relation between the polarimetry and spectral phase was seen when the spectra resemble Type Ic SNe during the photospheric and nebular phases. The light-curve decline rate, which spans a factor of eight, also shows no clear relation with the polarisation properties. While only slow-evolving SLSNe-I have shown non-zero polarisation, the fast-evolving ones have not been observed at sufficiently late times to conclude that none of them exhibit changing P. However, the four SLSNe-I with increasing polarisation degree also have irregular light-curve declines. For up to half of them, the photometric, spectroscopic, and polarimetric properties are affected by CSM interaction. As such, CSM interaction clearly plays an important role in understanding the polarimetric evolution of SLSNe-I.

show abstract

Pre-explosion Helium Shell Flash in Type Ia Supernovae

Cited by 2 publications

References 120 publications

A Pre-explosion Effervescent Zone for the Circumstellar Material in SN 2023ixf

A Pre-explosion Effervescent Zone for the Circumstellar Material in SN 2023ixf

Polarimetry of hydrogen-poor superluminous supernovae

Contact Info

Product

Resources

About