Explore the vast range of titles available.

The identities of the progenitors of type Ia supernova (SN∼Ia) has long been under study and remains an unsolved problem of astrophysics. The answer to this question will impact cosmology and subfields such as galactic evolution. To help resolve this issue and determine what systems give rise to SN∼Ia, the relationships between progenitor systems, their winds, and their environments are here considered, and a theoretical tool is created to model the consequences. I present theoretical semi-analytic models for the interaction of stellar winds with the interstellar medium (ISM). To investigate a wide range of possible winds and environments, I developed and employ piecewise, semi-analytical descriptions implemented in the code SPICE (Supernovae Progenitor Interaction Calculator for parameterized Environments, available on request), assuming spherical symmetry and power-law ambient density profiles. It is shown that a wide class of solutions can be found using the Buckingham $\\Pi$-theorem. Semi-analytic solutions allow us to test a wide variety of configurations, their dependencies on the wind and environment parameters, and find non-unique solutions within a set of observational constraints. SPICE may be used to model such interactions in different types of Supernovae (SNe), stellar winds, as well as modeling realistic feedback in star formation and large scale galactic evolution simulations. As one of the many potential applications for SPICE, here I study pre-conditioning of the environment of Type Ia Supernovae (SNe∼Ia), which may originate from two merging WDs, known as the double degenerate scenario (DD), or an accreting white dwarf star (WD) {from a non-degenerate companion}, known as the single degenerate scenario (SD). The wind of the progenitor systems may originate from the progenitor, a donor star, or an accretion disk (AD). The environment is determined by the ISM and/or the wind of the donor star or the wind of the progenitor star during a prior epoch. The free parameters are: the a) mass loss $\\dot{m}$, b) wind velocity $v_w$, c) density distributions $\\propto r{-s}$ of theISM, and d)} the duration of the wind prior to the supernova explosion. I discuss the observational signatures with respect to light curves and high resolution spectra as tools to probe the environment of SNe∼Ia. The specific properties and evolution of the progenitor systems are found to leave unique imprints. During the progenitor evolution and with typical parameters in the SD scenario, the winds create a low density bubble surrounding the progenitor system and a high-density shell. It is also found that accretion disk winds dominate the environment formation. Within a distance of several light-years (ly), the densities are smaller by factors of $10{2...4}$ compared to theenvironment. This explains the general lack of observed interaction in late time Supernova (SN) light curves for, at least, several years. The overdensities of the shells are between a factor of 4 to several hundred in case of constant density ISM and environments produced by stellar winds, respectively. The expansion velocity and width of the shell are typically 1-10 \\% of both $v_w$ and the contact discontinuity $R_C$ and may produce narrow spectral lines as observed in some SNe∼Ia. Typically, narrow circumstellar lines of equivalent width $\\approx 100 m\\mbox{\\normalfont{\\AA}}$ are found for uniform ISM typical in Spiral galaxies and $\\approx 1 m\\mbox{\\normalfont{\\AA}}$ for wind environments. The outer layers of a SNe∼Ia expands with velocities of 10 to 30 \\% of the speed of light and we may expect some interaction with the shells several years after the explosion. I apply the analysis to SN2014J and discuss several scenarios. For SN∼2014J, the environment is likely formed by the AD wind running into a region produced by the Red Giant (RG) wind from the progenitor star prior to its WD stage. The delay times between the formation of the WD and the explosion is suggested to be short, $\\sim 105∼yr$. Finally the same analysis is repeated with other well-observed SN, including SN2001fe, PTF 11kx, SN2006X, and SN2007le.

We present theoretical semi-analytic models for the interaction of stellar winds with the interstellar medium (ISM) or prior mass loss implemented in our code SPICE (Supernovae Progenitor Interaction Calculator for parameterized Environments, available on request), assuming spherical symmetry and power-law ambient density profiles and using the Pi-theorem. This allows us to test a wide variety of configurations, their functional dependencies, and to find classes of solutions for given observations. Here, we study Type Ia (SN~Ia) surroundings of single and double degenerate systems, and their observational signatures. Winds may originate from the progenitor prior to the white dwarf (WD) stage, the WD, a donor star, or an accretion disk (AD). For M_Ch explosions,the AD wind dominates and produces a low-density void several light years across surrounded by a dense shell. The bubble explains the lack of observed interaction in late time SN light curves for, at least, several years. The shell produces narrow ISM lines Doppler shifted by 10-100 km/s, and equivalent widths of approximately 100 mA and 1 mA in case of ambient environments with constant density and produced by prior mass loss, respectively. For SN 2014J, both mergers and M_Ch mass explosions have been suggested based on radio and narrow lines. As a consistent and most likely solution, we find an AD wind running into an environment produced by the RG wind of the progenitor during the pre-WD stage, and a short delay, 0.013 to 1.4 Myr, between the WD formation and the explosion. Our framework may be applied more generally to stellar winds and star-formation feedback in large scale galactic evolution simulations.