First author: Maximilian Stritzinger
We present a multi-band sequence of $Hubble~Space~Telescope$ images documenting the emergence and evolution of multiple light echoes (LEs) linked to the stripped-envelope supernova (SN) 2016adj located in the central dust-lane of Centaurus A. Following point-spread function subtraction, we identify the earliest LE emission associated with a SN at only $+$34 days (d) past the epoch of $B$-band maximum. Additional HST images extending through $+$578 d cover the evolution of LE1 taking the form of a ring, while images taken on $+$1991 d reveals not only LE1, but also segments of a new inner LE ring (LE2) as well as two additional outer LE rings (LE3 & LE4).
First author: Noam Soker
I argue that the assumption that the jets that shape the axisymmetrical morphological features of core collapse supernova (CCSN) remnants are post-kick jets, i.e., the neutron star (NS) launches these jets after the explosion and after it acquired its natal kick velocity, leads to the conclusion that the pre-collapse cores of CCSN progenitors have sufficient angular momentum fluctuations to support jittering jets that explode the star.
First author: Keiichi Maeda
Type Iax Supernovae (SNe Iax) form a class of peculiar SNe Ia, whose early-phase spectra share main spectral line identifications with canonical SNe Ia but with higher ionization and much lower line velocities. Their late-time behaviors deviate from usual SNe Ia in many respects; SNe Iax keep showing photospheric spectra over several 100 days and the luminosity decline is very slow. In the present work, we study the late-time spectra of SN Iax 2019muj including a newly-presented spectrum at ~500 days.
First author: B. Sykes
Fallback supernovae and the collapsar scenario for long-gamma ray burst and hypernovae have received considerable interest as pathways to black-hole formation and extreme transient events. Consistent simulations of these scenarios require a general relativistic treatment and need to deal appropriately with the formation of a singularity. Free evolution schemes for the Einstein equations can handle the formation of black holes by means of excision or puncture schemes.
First author: Sho Fujibayashi
We explore a possible scenario of the explosion as a result of core collapses of rotating massive stars that leave a black hole by performing a radiation-viscous-hydrodynamics simulation in numerical relativity. We take moderately and rapidly rotating compact pre-collapse stellar models derived in stellar evolution calculations as the initial conditions. We find that the viscous heating in the disk formed around the central black hole powers an outflow.
First author: Shuai Zha
Type IIP supernovae (SNe IIP) mark the explosive death of red supergiants (RSGs), evolved massive stars with an extended hydrogen envelope. They are the most common supernova type and allow for benchmarking of supernova explosion models by statistical comparison to observed population properties rather than comparing individual models and events. We construct a large synthetic set of SNe IIP light curves (LCs) using the radiation hydrodynamics code \texttt{SNEC} and explosion energies and nickel masses obtained from an efficient semi-analytic model for two different sets of stellar progenitor models.
First author: Paul K. H. Yeung
Hadronic $\gamma$-ray sources associated with supernova remnants (SNRs) can serve as stopwatches for the escape of cosmic rays from SNRs, which gradually develops from highest-energy particles to lowest-energy particles with time. In this work, we analyze the 13.7~yr \emph{Fermi}-LAT data to investigate the $\gamma$-ray feature in/around the SNR G298.6$-$0.0 region. With $\gamma$-ray spatial analyses, we detect three point-like components. Among them, Src-NE is at the eastern SNR shell, and Src-NW is adjacent to the western edge of this SNR.
First author: O. Petruk
The detected polarized radio emission from remnant of SN1987A opens the possibility to unveil the structure of the pre-supernova magnetic field in the circumstellar medium. Properties derived from direct measurements would be of importance for understanding the progenitor stars and their magnetic fields. As the first step to this goal, we adopted the hydrodynamic data from an elaborated three-dimensional (3-D) numerical model of SN1987A. We have developed an approximate method for reconstruction' of 3-D magnetic field structure inside supernova remnant on the hydrodynamic background’.
First author: Rachel J. Bruch
Spectroscopic detection of transient narrow emission lines (flash-ionisation features) traces the presence of circumstellar material (CSM) around massive stars exploding as core-collapse supernovae. Transient emission lines disappearing shortly after the SN explosion suggest that the spatial extent of this material is compact; hence implying that the progenitor star experienced episodes of enhanced mass loss shortly prior to explosion. The early light curves of Type II supernovae (SNe II) are assumed to be initially powered by shock-cooling emission.
First author: Tom Ben-Ami
Type Ibn supernovae (SNe) are a rare class of stellar explosions whose progenitor systems are not yet well determined. We present and analyze observations of the Type Ibn SN 2019kbj, and model its light curve in order to constrain its progenitor and explosion parameters. SN 2019kbj shows roughly constant temperature during the first month after peak, indicating a power source (likely CSM interaction) that keeps the continuum emission hot at ~15000K.
