Conveners
White Dwarf Explosions: Block 1
- Pilar Ruiz-Lapuente (ICCUB U. Barcelona and IFF (CSIC))
- Robert Fisher (University of Massachusetts Dartmouth)
White Dwarf Explosions: Block 2
- Robert Fisher (University of Massachusetts Dartmouth)
- Pilar Ruiz-Lapuente (ICCUB U. Barcelona and IFF (CSIC))
Description
Type Ia supernovae play a crucial role as standardizable candles for cosmology, and underpin measurements of both dark energy and the Hubble tension. Yet, the nature of the stellar progenitors and explosion mechanisms for type Ia supernovae remains an area of active research. This session will bring together members of the supernova cosmology community along with observers and theorists investigating the type Ia stellar progenitor problem and explosion mechanisms, and aims to achieve dialog on problems of interest linking both groups.
Particular areas of focus for the session include:
* Type Ia stellar progenitors and explosion mechanisms
* Multidimensional type Ia simulations
* Photometric and spectroscopic discriminants of type Ia progenitors, particularly at early and late times
* Evolutionary effects on SNe Ia supernova cosmology and their impact on dark energy measurements
* The absolute brightness of normal SNe Ia; the link of absolute brightness and the distance scale; views on the Hubble constant tension.
I will review current cosmological applications of Type Ia Supernovae (SN Ia) to measure the Hubble constant and constrain the nature of dark energy, with an emphasis on the limiting factors in these measurements. I will describe how near-infared observations of SN Ia provide an alternate path for future supernova cosmology. Astrophysical systematic uncertainties arise from our lack of...
Despite substantial progress in theoretical modeling and numerical simulations over the past years, our understanding of the physical mechanism of Type Ia supernovae remains incomplete. This has two main reasons. (i) The progenitor systems from which these explosions arise have not been identified, and therefore the initial conditions for the explosion simulations are uncertain. (ii) Modeling...
Our theoretical understanding of the progenitors of Type Ia supernovae has undergone a revolution in the last decade, with sub-Chandrasekhar-mass scenarios quickly coming to the forefront of research. In this talk, I will focus on the "dynamically driven double-degenerate double-detonation" (D6) scenario, in which a double detonation on a sub-Chandrasekhar-mass white dwarf takes place during...
What the progenitors of Type Ia supernovae (SNe Ia) are, whether they are Chandrasekhar mass or sub-Chandrasekhar mass white dwarfs, has been matter of debate for decades. Various observational hints are supporting both models as the main progenitor. In this talk, I will review the explosion physics and their chemical abundance patterns of SNe Ia from these two classes of progenitors. I will...
The progenitor scenarios of Type Ia supernovae remain a mystery having a crippling effect on the many area that have strong connections to these explosive events (e.g. cosmology, chemical evolution of the Universe, stellar evolution, etc.). The current viable scenarios can be divided into two broad categories: 1) 1.4 M$_\odot$ white dwarves that are likely created in an accretion process and...
Type Ia supernovae (SNe) are some of the most common cosmic transients, yet their progenitors are still not known. I will discuss the sub-Chandrasekhar mass pathway to these explosions, known as the double detonation scenario, where a White Dwarf (WD) is able to explode below the Chandrasekhar mass limit through the aid of an accreted helium shell. An ignition of this helium can send a shock...
In this work, we investigate the structure of polarized charged white dwarfs (WDs) with finite temperature as a possible type Ia supernovae source. The WD is considered with an isothermal core and an envelope where there is a temperature distribution that depends on the density. Regarding the hot fluid, we assume that it is composed of nucleons and electrons with temperature contributions. The...
Type Ia supernovae (SNe Ia) are excellent cosmological distance indicators. With them, one can precisely measure the expansion history of the Universe and constrain cosmological parameters such as the current expansion rate, H0, and the dark energy equation-of-state parameter, w. I will present new results from four current and upcoming surveys. The Swope Supernova Survey is a large,...
The detailed nature of type Ia supernovae (SNe Ia) remains uncertain, and as survey statistics increase, the question of astrophysical systematic uncertainties arises, notably that of the evolution of SN Ia populations. We study the dependence on redshift of the SN Ia light-curve stretch, which is a purely intrinsic SN property, to probe its potential redshift drift. The SN stretch has been...
In this presentation I analyze the robustness of the value of the Hubble-Lemaitre constant yielded by the cosmic distance ladder for Type Ia supernovae, which involves three rungs. In this analysis I hold fixed Rung 1 as the distance to the LMC determined to 1% using Detached Eclipsing Binary stars, in order to focus on the highest rungs. For Rung 2 I analyze two methods, the TRGB and Cepheid...
Infrared light curves of type Ia supernovae have been shown to provide an interesting pathway to extragalactic distances and a physical understanding of the explosions. The double peak provides interesting characteristics. The peak phases of the infrared relative to optical light curves gives an indication of the radiation physics and hints on why type Ia supernovae might be better standard...
We present a new measurement of the Hubble constant $(H_0)$ using supernovae type Ia (SNe Ia) based on the Surface Brightness Fluctuations (SBF) distance measurement method. We build a sample of calibrating anchors consisting of 24 SNe hosted in galaxies having SBF distance measurements. Applying a hierarchical Bayesian approach, we calibrate the SNe peak luminosity and extend it into the...
The precise value of Hubble's constant has become one of the most interesting cosmological tensions in recent years. Measurements of H_0 with Type Ia supernovae, in a series of papers by Reiss et al., use a distance ladder of parallax and Cepheid variable stars, and find a value of H_0 which is significantly higher than expected in a LCDM cosmology with Planck CMB parameters. In this work, we...
A large number of magnetized white dwarfs (WDs), with surface field strength generally less than 10$^9$ G, identified from wide-field surveys have helped us to understand their physical and chemical properties and the effect of magnetic field strength (B) on them. Though these weaker fields are not expected to modify their properties significantly, it is an excellent step for probing the...
The nature of stellar progenitors and the associated explosion mechanism of type Ia supernovae (SNIa) remains one of the major open questions in astrophysics. Virtually all existing theoretical models require formation of a supersonic
detonation wave capable of providing nearly complete incineration of the
stellar material of a WD after it becomes gravitationally unbound. The
mechanism of...
