scholarly journals Thermonuclear explosions of rapidly differentially rotating white dwarfs: Candidates for superluminous Type Ia supernovae?

2018 ◽  
Vol 618 ◽  
pp. A124 ◽  
Author(s):  
M. Fink ◽  
M. Kromer ◽  
W. Hillebrandt ◽  
F.K. Röpke ◽  
R. Pakmor ◽  
...  
Keyword(s):  
White Dwarfs ◽  
Three Dimensional ◽  
Radioactive Decay ◽  
Theoretical Explanation ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Chandrasekhar Limit ◽  
Ia Supernovae ◽  
First Time ◽  
Detonation Model

The observed sub-class of “superluminous” Type Ia supernovae lacks a convincing theoretical explanation. If the emission of such objects were powered exclusively by radioactive decay of 56Ni formed in the explosion, a progenitor mass close to or even above the Chandrasekhar limit for a non-rotating white dwarf star would be required. Masses significantly exceeding this limit can be supported by differential rotation. We, therefore, explore explosions and predict observables for various scenarios resulting from differentially rotating carbon–oxygen white dwarfs close to their respective limit of stability. Specifically, we have investigated a prompt detonation model, detonations following an initial deflagration phase (“delayed detonation” models), and a pure deflagration model. In postprocessing steps, we performed nucleosynthesis and three-dimensional radiative transfer calculations, that allow us, for the first time, to consistently derive synthetic observables from our models. We find that all explosion scenarios involving detonations produce very bright events. The observables predicted for them, however, are inconsistent with any known subclass of Type Ia supernovae. Pure deflagrations resemble 2002cx-like supernovae and may contribute to this class. We discuss implications of our findings for the explosion mechanism and for the existence of differentially rotating white dwarfs as supernova progenitors.

scholarly journals White dwarf accretion and type Ia supernovae

2012 ◽  
Vol 8 (S290) ◽  
pp. 117-120
Author(s):  
Z. Han ◽  
X. Chen
Keyword(s):  
White Dwarf ◽  
White Dwarfs ◽  
Type Ia Supernovae ◽  
Lower Mass ◽  
Type Ia ◽  
Chandrasekhar Limit ◽  
Ia Supernovae

AbstractType Ia supernovae (SNe Ia) are believed to be thermonuclear explosions of carbon-oxygen white dwarfs at a mass close to the Chandrasekhar limit. However, a white dwarf at birth has a significantly lower mass and needs to accrete mass to grow to the limit for the explosion. Various progenitor models have been proposed and those models play an important role in our understanding of SNe Ia and cosmology.

Three‐dimensional Delayed‐Detonation Model of Type Ia Supernovae

2005 ◽  
Vol 623 (1) ◽  
pp. 337-346 ◽  
Author(s):  
Vadim N. Gamezo ◽  
Alexei M. Khokhlov ◽  
Elaine S. Oran
Keyword(s):  
Three Dimensional ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Ia Supernovae ◽  
Detonation Model

scholarly journals The WD+He star binaries as the progenitors of type Ia supernovae

2017 ◽  
Vol 26 (1) ◽  
Author(s):  
Bo Wang ◽  
Dongdong Liu
Keyword(s):  
Parameter Space ◽  
Stellar Evolution ◽  
White Dwarfs ◽  
Type Ia Supernovae ◽  
Population Synthesis ◽  
Accretion Rates ◽  
Type Ia ◽  
Chandrasekhar Limit ◽  
Ia Supernovae ◽  
Modest Reduction

AbstractEmploying the MESA stellar evolution code, we computed He accretion onto carbon-oxygen white dwarfs (CO WDs).We found two possible outcomes for models in which the WD steadily grows in mass towards the Chandrasekhar limit. For relatively low He-accretion rates carbon ignition occurs in the center, leading to a type Ia supernova (SN Ia) explosion, whereas for relatively high accretion rates carbon is ignited off-center, probably leading to collapse. Thus the parameter space producing SNe Ia is reduced compared to what was assumed in earlier papers, in which the possibility of off-center ignition was ignored. We then applied these results in binary population synthesis modelling, finding a modest reduction in the expected birthrate of SNe Ia resulting from the WD+He star channel.

scholarly journals Imprint of modified Einstein’s gravity on white dwarfs: Unifying Type Ia supernovae

2015 ◽  
Vol 24 (12) ◽  
pp. 1544026 ◽  
Author(s):  
Upasana Das ◽  
Banibrata Mukhopadhyay
Keyword(s):  
White Dwarfs ◽  
Evolutionary History ◽  
Type Ia Supernovae ◽  
Single Model ◽  
Model Parameter ◽  
Type Ia ◽  
History Of ◽  
Ia Supernovae ◽  
First Time ◽  
The Universe

We establish the importance of modified Einstein’s gravity (MG) in white dwarfs (WDs) for the first time in the literature. We show that MG leads to significantly sub- and super-Chandrasekhar limiting mass WDs, depending on a single model parameter. However, conventional WDs on approaching Chandrasekhar’s limit are expected to trigger Type Ia supernovae (SNeIa), a key to unravel the evolutionary history of the universe. Nevertheless, observations of several peculiar, under- and over-luminous SNeIa argue for the limiting mass widely different from Chandrasekhar’s limit. Explosions of MG induced sub- and super-Chandrasekhar limiting mass WDs explain under- and over-luminous SNeIa respectively, thus unifying these two apparently disjoint sub-classes. Our discovery questions both the global validity of Einstein’s gravity and the uniqueness of Chandrasekhar’s limit.

scholarly journals Three‐Dimensional Simulations of the Deflagration Phase of the Gravitationally Confined Detonation Model of Type Ia Supernovae

2008 ◽  
Vol 681 (2) ◽  
pp. 1448-1457 ◽  
Author(s):  
G. C. Jordan IV ◽  
R. T. Fisher ◽  
D. M. Townsley ◽  
A. C. Calder ◽  
C. Graziani ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Ia Supernovae ◽  
Detonation Model ◽  
Three Dimensional Simulations

scholarly journals Gravitational Collapse versus Thermonuclear Explosion of Degenerate Stellar Cores

1994 ◽  
Vol 147 ◽  
pp. 186-213
Author(s):  
J. Isern ◽  
R. Canal
Keyword(s):  
Neutron Star ◽  
White Dwarfs ◽  
Light Curves ◽  
Type Ia Supernovae ◽  
Radioactive Elements ◽  
Border Line ◽  
Thermonuclear Explosion ◽  
Type Ia ◽  
Γ Rays ◽  
Ia Supernovae

AbstractIn this paper we review the behavior of growing stellar degenerate cores. It is shown that ONeMg white dwarfs and cold CO white dwarfs can collapse to form a neutron star. This collapse is completely silent since the total amount of radioactive elements that are expelled is very small and a burst of γ-rays is never produced. In the case of an explosion (always carbonoxygen cores), the outcome fits quite well the observed properties of Type Ia supernovae. Nevertheless, the light curves and the velocities measured at maximum are very homogeneous and the diversity introduced by igniting at different densities is not enough to account for the most extreme cases observed. It is also shown that a promising way out of this problem could be the He-induced detonation of white dwarfs with different masses. Finally, we outline that the location of the border line which separetes explosion from collapse strongly depends on the input physics adopted.

scholarly journals Three Hypervelocity White Dwarfs in Gaia DR2: Evidence for Dynamically Driven Double-degenerate Double-detonation Type Ia Supernovae

2018 ◽  
Vol 865 (1) ◽  
pp. 15 ◽  
Author(s):  
Ken J. Shen ◽  
Douglas Boubert ◽  
Boris T. Gänsicke ◽  
Saurabh W. Jha ◽  
Jennifer E. Andrews ◽  
...  
Keyword(s):  
White Dwarfs ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Ia Supernovae ◽  
Gaia Dr2

scholarly journals Multidimensional Parameter Study of Double Detonation Type Ia Supernovae Originating from Thin Helium Shell White Dwarfs

2021 ◽  
Vol 919 (2) ◽  
pp. 126
Author(s):  
Samuel J. Boos ◽  
Dean M. Townsley ◽  
Ken J. Shen ◽  
Spencer Caldwell ◽  
Broxton J. Miles
Keyword(s):  
White Dwarfs ◽  
Parameter Study ◽  
Type Ia Supernovae ◽  
Multidimensional Parameter ◽  
Type Ia ◽  
Ia Supernovae

scholarly journals Are the Precursors of Type Ia Supernovae Double Degenerate Mergers?

2004 ◽  
Vol 194 ◽  
pp. 111-112
Author(s):  
Lilia Ferrario
Keyword(s):  
Neutron Stars ◽  
White Dwarf ◽  
White Dwarfs ◽  
Observational Evidence ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Ia Supernovae

AbstractI argue that the observational evidence for white dwarf-white dwarf mergers supports the view that they give rise to ultra-massive white dwarfs or neutron stars through accretion induced collapse. The implications for the progenitors of Type Ia SNe are discussed.

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