Optical and Near-Infrared Observations of Sn 2013dx Associated With GRB 130702a

Cano

et al. 2017

ApJ

Broad-lined type Ic supernovae (SNe Ic-BL) are a subclass of rare core collapse SNe whose energy source is debated in the literature. Recently a series of investigations on SNe Ic-BL with the magnetar (plus 56 Ni) model were carried out. Evidence for magnetar formation was found for the well-observed SNe Ic-BL 1998bw and 2002ap. In this paper we systematically study a large sample of SNe Ic-BL not associated with gamma-ray bursts. We use photospheric velocity data determined in a homogeneous way. We find that the magnetar+ 56 Ni model provides a good description of the light curves and velocity evolution of our sample of SNe Ic-BL, although some SNe (not all) can also be described by the pure-magnetar model or by the two-component pure-56 Ni model (3 out of 12 are unlikely explained by two-component model). In the magnetar+ 56 Ni model, the amount of 56 Ni required to explain their luminosity is significantly reduced, and the derived initial explosion energy is, in general, in accordance with neutrino heating. Some correlations between different physical parameters are evaluated and their implications regarding magnetic field amplification and the total energy reservoir are discussed.

Section: Estimate the Appearance Of Nebular Features Fromcontrasting

confidence: 91%

A Monte Carlo Approach to Magnetar-powered Transients. II. Broad-lined Type Ic Supernovae Not Associated with GRBs

Cano

et al. 2017

ApJ

“…Also the Ca II showed similar high velocities, possibly hinting to some high velocity material coming from the progenitor core, as seen in GRB-SNe (e.g. Bufano et al 2012;Toy et al 2016;Ashall et al 2019).…”

Section: He Spectral Features As a Signature Of Asymmetries?mentioning

confidence: 62%

SN 2016coi (ASASSN-16fp): An Energetic H-stripped Core-collapse Supernova from a Massive Stellar Progenitor with Large Mass Loss

Terreran¹,

Margutti²,

Bersier³

et al. 2019

ApJ

Self Cite

We present comprehensive observations and analysis of the energetic H-stripped SN 2016coi (a.k.a. ASASSN-16fp), spanning the γ-ray through optical and radio wavelengths, acquired within the first hours to ∼420 days post explosion. Our observational campaign confirms the identification of He in the SN ejecta, which we interpret to be caused by a larger mixing of Ni into the outer ejecta layers. From the modeling of the broad bolometric light curve we derive a large ejecta mass to kinetic energy ratio (M ej ∼ 4 − 7 M , E k ∼ 7 − 8 × 10 51 erg). The small [Ca II] λλ7291,7324 to [O I] λλ6300,6364 ratio (∼0.2) observed in our latetime optical spectra is suggestive of a large progenitor core mass at the time of collapse. We find that SN 2016coi is a luminous source of X-rays (L X > 10 39 erg s −1 in the first ∼ 100 days post explosion) and radio emission (L 8.5 GHz ∼ 7 × 10 27 erg s −1 Hz −1 at peak). These values are in line with those of relativistic SNe (2 pre-explosion progenitor mass-loss with rateṀ ∼ (1 − 2) × 10 −4 M yr −1 and a sub-relativistic shock velocity v sh ∼ 0.15c, in stark contrast with relativistic SNe and similar to normal SNe. Finally, we find no evidence for a SN-associated shock breakout γ-ray pulse with energy E γ > 2 × 10 46 erg. While we cannot exclude the presence of a companion in a binary system, taken together, our findings are consistent with a massive single star progenitor that experienced large mass loss in the years leading up to core-collapse, but was unable to achieve complete stripping of its outer layers before explosion.

“…Even today, the bulk of the analyses of LGRB/SNe and standard SNe Ic is based on a simplistic 1D modelling of the LC and/or no modelling of the spectra (for recent studies, see, e.g., Drout et al 2011;D'Elia et al 2015;Toy et al 2016;Prentice et al 2016;Volnova et al 2016). There is a persisting controversy with the origin of LGRB/SNe.…”

Section: Introductionmentioning

confidence: 99%

Radiative-transfer models for explosions from rotating and non-rotating single WC stars

Hillier

Yoon

Waldman

et al. 2017

A&A

Using 1-D non-Local-Thermodynamic-Equilibrium time-dependent radiative-transfer simulations, we study the ejecta properties required to match the early and late-time photometric and spectroscopic properties of supernovae (SNe) associated with long-duration γ-ray bursts (LGRBs). To match the short rise time, narrow light curve peak, and extremely broad spectral lines of SN 1998bw requires a model with ∼ < 3 M ejecta but a high explosion energy of a few 10 52 erg and 0.5 M of 56 Ni. However the relatively high luminosity, the presence of narrow spectral lines of intermediate mass elements, and the low ionisation at the nebular stage are matched with a more standard C-rich Wolf-Rayet (WR) star explosion, with an ejecta of ∼ > 10 M , an explosion energy ∼ > 10 51 erg, and only 0.1 M of 56 Ni. As the two models are mutually exclusive, the breaking of spherical symmetry is essential to match the early/late photometric/spectroscopic properties of SN 1998bw. This conclusion confirms the notion that the ejecta of SN 1998bw is aspherical on large scales. More generally, with asphericity, the energetics and 56 Ni mass of LGRB/SNe are reduced and their ejecta mass is increased, favoring a massive fast-rotating Wolf-Rayet star progenitor. Contrary to persisting claims in favor of the proto-magnetar model for LGRB/SNe, such progenitor/ejecta properties are compatible with collapsar formation. Ejecta properties of LGRB/SNe inferred from 1D radiative-transfer modeling are fundamentally flawed.