Related papers: The Physics of Flash (Supernova) Spectroscopy

We present six epochs of optical spectropolarimetry of the Type II supernova (SN) 2023ixf ranging from $\sim$ 2 to 15 days after the explosion. Polarimetry was obtained with the Kast double spectrograph on the Shane 3 m telescope at Lick…

A longstanding problem in the study of supernovae (SNe) has been the relationship between the Type IIP and Type IIL subclasses. Whether they come from distinct progenitors or they are from similar stars with some property that smoothly…

Supernovae (SNe) with strong interactions with circumstellar material (CSM) are promising candidate sources of high-energy neutrinos and gamma rays, and have been suggested as an important contributor to Galactic cosmic rays beyond 1 PeV.…

Early-time light curves/spectra of some hydrogen-rich supernovae (SNe) give firm evidence on the existence of confined, dense circumstellar matter (CSM) surrounding dying massive stars. We numerically and analytically study radiative…

XRF 030723 is the first X-ray flash (XRF) to show in its optical light curve (LC) a bump that has been interpreted as the signature of a supernova (SN). After subtracting the afterglow component from the observed optical LC of the XRF…

Deep optical CCD images of the supernova remnant G 15.1-1.6 were obtained and filamentary and diffuse emission has been discovered. The images, taken in the emission lines of Halpha+[N II], [S II] and [O III], reveal filamentary and diffuse…

We present the first quantitative spectroscopic modeling of an early-time supernova that interacts with its progenitor wind. Using the radiative transfer code CMFGEN, we investigate the recently-reported 15.5 h post-explosion spectrum of…

Supernovae (SNe) inject $\sim 10^{51}$ erg in the interstellar medium, thereby shocking and heating the gas. A substantial fraction of this energy is later lost via radiative cooling. We present a post-processing module for the FLASH code…

Supernovae and their remnants provide energetic feedback to the ambient interstellar medium (ISM), which is often distributed in multiple gas phases. Among them, warm molecular hydrogen (H$_2$) often dominates the cooling of the shocked…

The spectra of type IIn supernovae indicate the presence of apre-existing slow, dense circumstellar wind (CSW). If the CSW extends sufficiently far from the progenitor star, then dust formation should occur in the wind. The light from the…

The conventional picture for the origin of the polarization of a supernova is based on a model of Thomson or resonance scattering of photons traveling through an aspherical supernova atmosphere. Positive detection of intrinsic polarization…

Recent studies have shown that K-luminous galaxies at 2<z<2.5 have high Halpha line widths and high [NII]/Halpha ratios. If these lines arise from photo-ionization by massive stars in HII regions these results imply that massive, metal rich…

We present the first calibrated CCD images of the faint supernova remnant G 114.3+0.3 in the emission lines of [OII], [OIII], Halpha+[NII] and [SII]. The deep low ionization CCD images reveal diffuse emission in the south and central areas…

The presumed Wolf-Rayet star progenitors of Type Ib/c supernovae have fast, low density winds and the shock waves generated by the supernova interaction with the wind are not expected to be radiative at typical times of observation. The…

The interaction of supernova ejecta with a surrounding circumstellar medium (CSM) generates a strong shock which can convert the ejecta kinetic energy into observable radiation. Given the diversity of potential CSM structures (arising from…

We present results from observations of SN 1979C with XMM-Newton in X-rays and in the UV, archival X-ray and HST data, and follow-up ground-based optical imaging. The XMM-Newton MOS spectrum shows two-temperature thermal plasma emission…

We show that a collisionless shock necessarily forms during the shock breakout of a supernova (SN) surrounded by an optically thick wind. An intense non-thermal flash of <~ MeV gamma rays, hard X-rays and multi-TeV neutrinos is produced…

Massive stars (>8 $M_{\odot}$) often undergo intense mass loss through winds or eruptive events in the final stages of their evolution, leading to the formation of a dense circumstellar medium (CSM). This material, expelled months to years…

Much difficulty has so far prevented the emergence of a consistent scenario for the origin of Type Ib and Ic supernovae (SNe). Here, we follow a heuristic approach by examining the fate of helium stars in the mass range 4 to 12Msun, which…

(Abridged) Some supernovae (SNe) may be powered by the interaction of the SN ejecta with a large amount of circumstellar matter (CSM). Here we outline a method to measure the mass of the optically thick CSM around such SNe. We present…