Open Issues in Core Collapse Supernova Theory

Open Issues in Core Collapse Supernova Theory PDF Author: Anthony Mezzacappa
Publisher: World Scientific
ISBN: 9812703446
Category : Science
Languages : en
Pages : 475

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Book Description
Efforts to uncover the explosion mechanism of core collapse supernovae and to understand all of their associated phenomena have been ongoing for nearly four decades. Despite this, our theoretical understanding of these cosmic events remains limited; two- and three-dimensional modeling of these events is in its infancy. Most of the modeling efforts over the past four decades have, by necessity, been constrained to spherical symmetry, with the first two-dimensional, albeit simplified, models appearing only during the last decade. Simulations to understand the complex interplay between the turbulent stellar core fluid flow, its magnetic fields, the neutrinos produced in and emanating from the proto-neutron star, the stellar core rotation, and the strong gravitational fields have yet to be performed. Only subsets of these fundamental ingredients have been included in the models thus far, often with approximation. The purpose of this volume is to identify the outstanding issues that remain in order to come to a complete understanding of these important astrophysical events. As the book focuses on open issues rather than the current state of the art in the field OCo although the latter will certainly be discussed OCo it will remain relevant for some time."

Open Issues in Core Collapse Supernova Theory

Open Issues in Core Collapse Supernova Theory PDF Author: Anthony Mezzacappa
Publisher: World Scientific
ISBN: 9812703446
Category : Science
Languages : en
Pages : 475

Get Book Here

Book Description
Efforts to uncover the explosion mechanism of core collapse supernovae and to understand all of their associated phenomena have been ongoing for nearly four decades. Despite this, our theoretical understanding of these cosmic events remains limited; two- and three-dimensional modeling of these events is in its infancy. Most of the modeling efforts over the past four decades have, by necessity, been constrained to spherical symmetry, with the first two-dimensional, albeit simplified, models appearing only during the last decade. Simulations to understand the complex interplay between the turbulent stellar core fluid flow, its magnetic fields, the neutrinos produced in and emanating from the proto-neutron star, the stellar core rotation, and the strong gravitational fields have yet to be performed. Only subsets of these fundamental ingredients have been included in the models thus far, often with approximation. The purpose of this volume is to identify the outstanding issues that remain in order to come to a complete understanding of these important astrophysical events. As the book focuses on open issues rather than the current state of the art in the field OCo although the latter will certainly be discussed OCo it will remain relevant for some time."

Topics in Core-collapse Supernova Theory

Topics in Core-collapse Supernova Theory PDF Author: Evan Patrick O'Connor
Publisher:
ISBN:
Category : Black holes (Astronomy)
Languages : en
Pages : 310

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Book Description


Open Issues in Core Collapse Supernova Theory

Open Issues in Core Collapse Supernova Theory PDF Author: Anthony Mezzacappa
Publisher: World Scientific
ISBN: 9812563148
Category : Science
Languages : en
Pages : 478

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Book Description
Efforts to uncover the explosion mechanism of core collapse supernovae and to understand all of their associated phenomena have been ongoing for nearly four decades. Despite this, our theoretical understanding of these cosmic events remains limited; two- and three-dimensional modeling of these events is in its infancy. Most of the modeling efforts over the past four decades have, by necessity, been constrained to spherical symmetry, with the first two-dimensional, albeit simplified, models appearing only during the last decade. Simulations to understand the complex interplay between the turbulent stellar core fluid flow, its magnetic fields, the neutrinos produced in and emanating from the proto-neutron star, the stellar core rotation, and the strong gravitational fields have yet to be performed. Only subsets of these fundamental ingredients have been included in the models thus far, often with approximation.The purpose of this volume is to identify the outstanding issues that remain in order to come to a complete understanding of these important astrophysical events. As the book focuses on open issues rather than the current state of the art in the field ? although the latter will certainly be discussed ? it will remain relevant for some time.

Topics in the Theory of Core-collapse Supernovae (PHD).

Topics in the Theory of Core-collapse Supernovae (PHD). PDF Author: Todd A. Thompson
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description


Interpreting Gravitational Waves and Developing Relativistic Multiphysics Solvers for Core-collapse Supernova Simulations

Interpreting Gravitational Waves and Developing Relativistic Multiphysics Solvers for Core-collapse Supernova Simulations PDF Author: Michael Anton Pajkos
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0

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Book Description
Core-collapse supernovae (CCSNe) mark the endpoint for millions of years of massive stellar evolution. After a successful explosion, supernovae increase the metallicity of the interstellar medium, generate intense electromagnetic radiation ionizing their surroundings, generate compact objects such as black holes or neutron stars, and create ripples in spacetime-gravitational waves (GWs). Advances in supernova theory over the past few decades have furthered our understanding of CCSNe. However, constraints on the physics enshrouded in the supernova center would further illuminate their explosion mechanisms. Advances in high performance computing (HPC) resources and the ever-increasing sensitivities of GW observatories have positioned the field of astrophysics between two recent technological advances. The work presented here leverages HPC to perform CCSN simulations, allowing astronomers to translate between GW signals and internal physics. Using this insight, astronomers are better positioned to constrain the physics driving these explosive events that have such a widespread influence throughout astronomy.Investigating the evolution of 12-, 20-, 40-, and 60 M[ancient] progenitors, I perform axisymmetric neutrino radiation-hydrodynamic CCSN simulations, to relate the convective activity behind the supernova shock to the expected GW strength. I quantify how the rotational content of the supernova lowers GW frequencies. I present a novel method that combines two features of a single GW event to constrain the mass distribution within the stellar progenitor. By only requiring the two most detectable parts of the GW signal, astronomers can also potentially predict the explosion properties 8́ơdays before shock breakout. I present work with my undergraduate research assistant, that considers the impact of viewing angle on detecting GWs from CCSNe. Presented is a novel analysis method to identify the distribution of GW emission over all angles, accompanied with results showing that the preferred direction of GW emission for CCSNe migrates over time.Lastly, I present new numerical solvers targeted at exascale computing platforms that account for magnetized fluid evolution with velocities near the speed of light and in extreme spacetimes. These solvers are accompanied with stringent baseline tests, paired with 1D and 2D supernova simulations making use of these features.

The Explosion Mechanism of Core-Collapse Supernovae

The Explosion Mechanism of Core-Collapse Supernovae PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The explosion of core-collapse supernova depends on a sequence of events taking place in less than a second in a region of a few hundred kilometers at the center of a supergiant star, after the stellar core approaches the Chandrasekhar mass and collapses into a proto-neutron star, and before a shock wave is launched across the stellar envelope. Theoretical efforts to understand stellar death focus on the mechanism which transforms the collapse into an explosion. Progress in understanding this mechanism is reviewed with particular attention to its asymmetric character. We highlight a series of successful studies connecting observations of supernova remnants and pulsars properties to the theory of core-collapse using numerical simulations. The encouraging results from first principles models in axisymmetric simulations is tempered by new puzzles in 3D. The diversity of explosion paths and the dependence on the pre-collapse stellar structure is stressed, as well as the need to gain a better understanding of hydrodynamical and MHD instabilities such as SASI and neutrino-driven convection. The shallow water analogy of shock dynamics is presented as a comparative system where buoyancy effects are absent. This dynamical system can be studied numerically and also experimentally with a water fountain. Lastly, we analyse the potential of this complementary research tool for supernova theory. We also review its potential for public outreach in science museums.

Cosmic Explosions in Three Dimensions

Cosmic Explosions in Three Dimensions PDF Author: Peter Höflich
Publisher: Cambridge University Press
ISBN: 9781139456616
Category : Science
Languages : en
Pages : 396

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Book Description
Supernovae and gamma-ray bursts are the strongest explosions in the Universe. Observations show that, rather than being symmetrical, they are driven by strong jets of energy and other asymmetrical effects. These observations demand theories and computations that challenge the biggest computers. This volume marks the transition to a fresh paradigm in the study of stellar explosions. It highlights the burgeoning era of routine supernova polarimetry and the insights into core collapse and thermonuclear explosions. With chapters by leading scientists, the book summarises the status of a fresh perspective on stellar explosions and should be a valuable resource for graduate students and research scientists.

Stellar Collapse

Stellar Collapse PDF Author: Chris L. Fryer
Publisher: Springer Science & Business Media
ISBN: 9781402019920
Category : Mathematics
Languages : en
Pages : 454

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Book Description
Supernovae, hypernovae and gamma-ray bursts are among the most energetic explosions in the universe. The light from these outbursts is, for a brief time, comparable to billions of stars and can outshine the host galaxy within which the explosions reside. Most of the heavy elements in the universe are formed within these energetic explosions. Surprisingly enough, the collapse of massive stars is the primary source of not just one, but all three of these explosions. As all of these explosions arise from stellar collapse, to understand one requires an understanding of the others. Stellar Collapse marks the first book to combine discussions of all three phenomena, focusing on the similarities and differences between them. Designed for graduate students and scientists newly entering this field, this book provides a review not only of these explosions, but the detailed physical models used to explain them from the numerical techniques used to model neutrino transport and gamma-ray transport to the detailed nuclear physics behind the evolution of the collapse to the observations that have led to these three classes of explosions.

Sensitivity of Neutrino-driven Core-collapse Supernova Models to the Microphysical Equation of State

Sensitivity of Neutrino-driven Core-collapse Supernova Models to the Microphysical Equation of State PDF Author: Ryan Elliott Landfield
Publisher:
ISBN:
Category : Gravitational waves
Languages : en
Pages : 162

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Book Description
The aim of this dissertation is to explore the sensitivity of neutrino-driven core collapse supernova physics to the microphysical equation of state of the stellar matter. Core collapse supernovae result from the gravitational collapse and ensuing explosion of massive stars. The most fundamental question in core collapse supernova (CCSN) theory is the mechanism of shock revival leading to the observed supernova explosion. The leading scenario is that neutrinos trapped in the proto-neutron star (PNS) during its formation escape and reheat the inner shock, reviving the shockwave, which expands outward, ejecting the star's outer shells into space. Given the central importance of the delayed heating mechanism to the dynamics of CCSNe, detailed studies of the dynamics of the neutrino heating mechanism, neutrino and gravitational wave (GW) signatures, and the dependence on both neutrino-matter interaction rates and the nuclear equation of state (EOS) are needed. The first direct detection of a GW emission from a CCSN would allow for a qualitative investigation into the accuracy of existing nuclear-force models via the EOS. Hence accurate CCSN numerical models are imminently necessary to predict and interpret such GW signatures. A tandem measurement of neutrino signature modulations and GWs would provide direct information about the CCSN mechanism and further our insight into the origins of neutron star rotation and kicks. In order to enhance the computational capability of the ORNL/UTK CCSN simulations, firstly I have developed the capacity to implement different pre-processed state-of-the-art EOS tables in the ORNL/UTK multi-D SN code CHIMERA. I have developed the multi-purpose EOS/Opacity table repository WeakLib for this purpose. Secondly, I have implemented these different EOS in 1D and 2D CHIMERA to study the impact of the EOS on the collapse, bounce, and post-bounce dynamics of the CCSNe explosion, as well as the impact on neutrino emission signals.

The Physics of Supernovae and Their Mathematical Models

The Physics of Supernovae and Their Mathematical Models PDF Author: Alexey G Aksenov
Publisher:
ISBN: 9789811285097
Category : Science
Languages : en
Pages : 0

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Book Description
"This book is dedicated to the theory of supernovae, focussing on new computational methods and simulations. It contains three parts: basic principles, numerical methods, and applications. The first part contains the non-formal introduction into the topics of supernovae, Boltzmann kinetic equations - with details of two particles reaction rate calculations - and the transformation of Boltzmann kinetic equations into hydrodynamic elements of statistical physics. It contains the equation of state for matter of high energy density, with details of calculations for thermodynamic parameters, weak interactions reaction rate details, and thermonuclear burning. The second part introduces elements of computational physics. The book collects not only generally accepted simulations methods, it also includes original approaches of the authors from two Russian groups in Supernovae, from the Keldysh Institute of Applied Mathematics and Institute for Theoretical and Experimental Physics. The book closes with a presentation of original works about the regime of burning in degenerate carbon-oxygen cores, a neutrino transport in supernovae type II, simulation of GR coalescence of neutron stars, aspherical nucleosynthesis in a core-collapse supernova, and thermalization in pair of plasma wind from a compact strange star. It contains the necessary information for a person to start independent research in this fast-developing field. It is therefore an important read for new researchers in this subject"--