Related papers: Spectral Models for Early Time SN 2011fe Observati…
Two "twin" Type Ia supernovae (SNe Ia), SNe 2011by and 2011fe, have extremely similar optical light-curve shapes, colors, and spectra, yet have different ultraviolet (UV) continua as measured in Hubble Space Telescope spectra and measurably…
Ultraviolet (UV) observations of Type Ia supernovae (SNe Ia) are crucial for constraining the properties of their progenitor systems. Theoretical studies predicted that the UV spectra, which probe the outermost layers of a SN, should be…
In Type Ia Supernovae (\sneia), the relative abundances of chemical elements are affected by the neutron excess in the composition of the progenitor white dwarf. Since these products leave signatures in the spectra near maximum light,…
Ultraviolet (UV) observations of Type Ia supernovae (SNe Ia) probe the outermost layers of the explosion, and UV spectra of SNe Ia are expected to be extremely sensitive to differences in progenitor composition and the details of the…
The analytical model found that the intrinsic variation in the initial metallicity of the Type Ia supernova (SN Ia) progenitor stars ($Z_{progenitor}$) translates into a 25% variation in the $^{56}$Ni mass synthesized and, therefore, 0.2…
We present ultraviolet line identifications of near maximum-light HST observations of SN 2011fe using synthetic spectra generated from both SYNOW and $\texttt{PHOENIX}$. We find the spectrum to be dominated by blends of iron group elements…
Spectral modelling of SNII atmospheres indicates a clear dependence of metal line strengths on progenitor metallicity. This motivates further work to evaluate the accuracy with which these SNe can be used as metallicity indicators. To…
The Type Ia supernovae (SNe Ia) 2011by, hosted in NGC 3972, and 2011fe, hosted in M101, are optical "twins," having almost identical optical light-curve shapes, colours, and near-maximum-brightness spectra. However, SN 2011fe had…
The early lightcurves of Type Ia supernovae (SNe Ia) can be used to test predictions about their progenitor systems. If the progenitor system consists of a single white dwarf in a binary with a Roche-lobe-overflowing non-degenerate stellar…
We present well-sampled optical observations of the bright Type Ia supernova (SN~Ia) SN 2011fe in M101. Our data, starting from $\sim16$ days before maximum light and extending to $\sim463$ days after maximum, provide an unprecedented time…
The effect of metallicity on the observed light of Type Ia supernovae (SNe Ia) could lead to systematic errors as the absolute magnitudes of local and distant SNe Ia are compared to measure luminosity distances and determine cosmological…
2003fg-like Type Ia supernovae (03fg-like SNe Ia) are rare subtype of SNe Ia, photometrically characterized by broader optical light curves and bluer ultraviolet (UV) colors compared to normal SNe Ia. In this work, we study four 03fg-like…
The effect of progenitor metallicity on Type Ia Supernovae (SNe Ia) has important cosmological implications due to the need for these standardizable candles to be compared across large spans of cosmic time in which the progenitor stars…
Late-time spectra of Type Ia supernovae (SNe Ia) are important in clarifying the physics of their explosions, as they provide key clues to the inner structure of the exploding white dwarfs. We examined late-time optical spectra of 36 SNe…
The nearby supernova SN 2011fe can be observed in unprecedented detail. Therefore, it is an important test case for Type Ia supernova (SN Ia) models, which may bring us closer to understanding the physical nature of these objects. Here, we…
We have calculated a grid of photospheric phase atmospheres of Type Ia supernovae (SNe Ia) with metallicities from ten times to one thirtieth the solar metallicity in the C+O layer of the deflagration model, W7. We have modeled the spectra…
It has been widely accepted that Type Ia supernovae (SNe Ia) are thermonuclear explosions of a CO white dwarf. However, the natures of the progenitor system(s) and explosion mechanism(s) are still unclarified. Thanks to the recent…
Hubble Space Telescope spectroscopic observations of the nearby type Ia supernova (SN Ia) SN2011fe, taken on 10 epochs from -13.1 to +40.8 days relative to B-band maximum light, and spanning the far-ultraviolet (UV) to the near-infrared…
Radiative transfer studies of Type Ia supernovae (SNe Ia) hold the promise of constraining both the time-dependent density profile of the SN ejecta and its stratification by element abundance which, in turn, may discriminate between…
The nearby Type Ia supernovae (SNe Ia) 2011fe and 2011by had nearly identical photospheric phase optical spectra, light-curve widths, and photometric colours, but at peak brightness SN 2011by reached a fainter absolute magnitude in all…