Two supernovae detected in the Hubble Deep Field (HDF) using the original December 1995 epoch and data from a shorter (63000 s in F814W) December 1997 visit with HST are discussed. The supernovae (SNe) are both associated with distinct galaxies at redshifts of 0.95 (spectroscopic) from Cohen et al. (1996) and 1.32 (photometric) from the work of Fernández-Soto, Lanzetta, & Yahil (1998). These re...

We explore the effects on nucleosynthesis in Type II supernovae of various parameters (mass cut, neutron excess, explosion energy, progenitor mass) in order to explain the observed trends of the ironpeak element abundance ratios ([Cr/Fe], [Mn/Fe], [Co/Fe] and [Ni/Fe]) in halo stars as a function of metallicity for the range −4 ≤ [Fe/H] ≤ −2.5. [Cr/Fe] and [Mn/Fe] decrease with decreasing [Fe/H]...

We apply deep recurrent neural networks, which are capable of learning complex sequential information, to classify supernovae. The observational time and filter fluxes are used as inputs to the network, but since the inputs are agnostic additional data such as host galaxy information can also be included. Using the Supernovae Photometric Classification Challenge (SPCC) data, we find that deep n...

Knowledge of the progenitors of core-collapse supernovae is a fundamental component in understanding the explosions. The recent progress in finding such stars is reviewed. The minimum initial mass that can produce a supernova has converged to 8± 1M⊙, from direct detections of red supergiant progenitors of II-P SNe and the most massive white dwarf progenitors, although this value is model depend...

A chemical evolution model following the evolution of the abundances of H, He, C, N, O and Fe for dwarf irregular and blue compact galaxies is presented. This model takes into account detailed nucleosynthesis and computes in detail the rates of supernovae of type II and I. The star formation is assumed to have proceeded in short but intense bursts. The novelty relative to previous models is tha...

Monte Carlo approaches to radiation transport have several attractive properties compared to deterministic methods. These include simplicity of implementation, high accuracy, and good parallel scaling. Moreover, Monte Carlo methods can handle complicated geometries and are relatively easy to extend to multiple spatial dimensions, which makes them particularly interesting in modeling complex mul...

ABSTRACT Stars in the mass range from 8 M? to 10 are expected produce one of two types supernovae (SNe), either electron-capture (ECSNe) or core-collapse (CCSNe), depending on their previous evolution. Either associated progenitors retain extended and massive hydrogen-rich envelopes observables these SNe are, therefore, be similar. In this study, we explore differences SNe. Specifically, invest...

The source of fluorine is not well understood, although core-collapse supernovae, Wolf-Rayet stars, and asymptotic giant branch stars have been suggested. A search for evidence of the -process during Type II supernovae is presented. Absorption from interstellar F i is seen in spectra of HD 208440 and HD 209339A acquired with the Far Ultraviolet Spectroscopic Explorer. In order to extract the co...

Using observations from an extensive monitoring campaign with the Hubble Space Telescope we present the detection of an intermediate time flux excess which is redder in color relative to the afterglow of GRB 011121, currently distinguished as the gamma-ray burst with the lowest known redshift. The red “bump,” which exhibits a spectral roll-over at ∼7200 Å, is well described by a redshifted Type...

The source of fluorine is not well understood, although core-collapse supernovae, Wolf-Rayet stars, and asymptotic giant branch stars have been suggested. A search for evidence of the ν process during Type II supernovae is presented. Absorption from interstellar F I is seen in spectra of HD 208440 and HD 209339A acquired with the Far Ultraviolet Spectroscopic Explorer. In order to extract the c...