Nuclear Detonation Around Compact Objects
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Black-Hole Binaries, Gravitational Waves, and Numerical Relativity
Black-hole binaries, gravitational waves, and numerical relativity Joan Centrella∗ and John G. Baker† Gravitational Astrophysics Laboratory, NASA/GSFC, 8800 Greenbelt Road, Greenbelt, Maryland 20771, USA Bernard J. Kelly‡ and James R. van Meter§ CRESST and Gravitational Astrophysics Laboratory, NASA/GSFC, 8800 Greenbelt Road, Greenbelt, Maryland 20771, USA and Department of Physics, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA (Dated: November 30, 2010) Understanding the predictions of general relativity for the dynamical interactions of two black holes has been a long-standing unsolved problem in theoretical physics. Black-hole mergers are monu- mental astrophysical events, releasing tremendous amounts of energy in the form of gravitational radiation, and are key sources for both ground- and space-based gravitational-wave detectors. The black-hole merger dynamics and the resulting gravitational waveforms can only be calculated through numerical simulations of Einstein’s equations of general relativity. For many years, nu- merical relativists attempting to model these mergers encountered a host of problems, causing their codes to crash after just a fraction of a binary orbit could be simulated. Recently, however, a series of dramatic advances in numerical relativity has allowed stable, robust black-hole merger simulations. This remarkable progress in the rapidly maturing field of numerical relativity, and the new understanding of black-hole binary dynamics that is emerging is chronicled. Important applications of these fundamental physics results to astrophysics, to gravitational-wave astronomy, and in other areas are also discussed. Contents G. Numerical Approximation Methods 15 H. Extracting the Physics 15 I. Prelude 2 V. Black-Hole Merger Dynamics and Waveforms 16 II. -
Are Gamma-Ray Bursts Signals of Supermassive Black Hole Formation?
Are Gamma-Ray Bursts Signals of Supermassive Black Hole Formation? K. Abazajian, G. Fuller, X. Shi Department of Physics, University of California, San Diego, La Jolla, California 92093-0350 Abstract. The formation of supermassive black holes through the gravitational 4 collapse of supermassive objects (M ∼> 5 × 10 M⊙) has been proposed as a source of cosmological γ-ray bursts. The major advantage of this model is that such collapses are far more energetic than stellar-remnant mergers. The major drawback of this idea is the severe baryon loading problem in one-dimensional models. We can show that the observed log N − log P (number vs. peak flux) distribution for gamma-ray bursts in the BATSE database is not inconsistent with an identification of supermassive object collapse as the origin of the gamma-ray bursts. This conclusion is valid for a range of plausible cosmological and γ-ray burst spectral parameters. 1. Introduction We investigate aspects of a recent model for the internal engine powering γ-ray bursts (GRBs). This model produces a GRB fireball through neutrino emission and annihilation during the collapse of a supermassive object into a black hole (Fuller & Shi, 1998). This supermassive object may either be a relativistic cluster of stars or a single supermassive star. The collapse of a supermassive object provides an exceedingly large amount of energy to power the burst, much higher than the amount of energy available in stellar remnant models. In addition, the rate of collapse of these objects–when associated with galaxy-type structures–is arXiv:astro-ph/9812287v1 15 Dec 1998 similar to the GRB rate. -
Gamma Ray Bursts from Stellar Collisions
CORE Metadata, citation and similar papers at core.ac.uk Provided by CERN Document Server Gamma Ray Bursts from Stellar Collisions Brad M.S. Hansen & Chigurupati Murali Canadian Institute for Theoretical Astrophysics University of Toronto, Toronto, ON M5S 3H8, Canada Received ; accepted –2– ABSTRACT We propose that the cosmological gamma ray bursts arise from the collapse of neutron stars to black holes triggered by collisions or mergers with main sequence stars. This scenario represents a cosmological history qualitatively different from most previous theories because it contains a significant contribution from an old stellar population, namely the globular clusters. Furthermore, the gas poor central regions of globular clusters provide an ideal environment for the generation of the recently confirmed afterglows via the fireball scenario. Collisions resulting from neutron star birth kicks in close binaries may also contribute to the overall rate and should lead to associations between some gamma ray bursts and supernovae of type Ib/c. Subject headings: stars:neutron–supernovae:general–globular clusters:general– gamma rays:bursts– Galaxy:evolution –3– 1. Introduction The detection of X-ray, optical and radio afterglows from gamma-ray burst events (Costa et al 1997; van Paradijs et al 1997, Sahu et al 1997; Frail et al 1997) and concommitant redshifts (Metzger et al 1997) has provided strong support for the cosmological origin of the phenomenon. The success of the fireball model (Cavallo & Rees 1978; Rees & Meszaros 1992; Meszaros & Rees 1993) is largely independent of the origin of the energy, requiring only an energetic and baryon-poor event confined to small scales, thereby giving rise to a relativistic and optically thick outflow. -
Stellar Explosions
Chapter 11: Stellar Explosions Prof. Douglas Laurence AST 1002 What are Stellar Explosions? Stellar remnant, probably a neutron star. • When stars above a certain mass die (run out of fuel at their core), they will literally explode in novae, supernovae, or hypernovae • The explosions “blows away” some of the star, leaving a stellar remnant, which can be: • A white dwarf • A neutron star • Or a black hole Stellar and Remnants Masses • Stars with a (main sequence) mass < 8#⊙ will eventually become white dwarfs. • White dwarfs have a remnant mass < 1.4#⊙, known as the Chandrasekhar limit. • Stars with a mass < 25#⊙will eventually become neutron stars. • Neutron stars have a remnant mass < 3#⊙, known as the Tolman-Oppenheimer- Volkoff (TOV) limit. • Stars with mass > 25#⊙, or remnant mass > 3#⊙, become black holes. • What a star becomes is determined by the remnant mass; remnant masses trend with main sequence masses, but they’re the decider. • A star with a very large mass can have a dramatically lower remnant mass after a stellar explosion, if the explosion blows away much of the star’s mass. Novae and White Dwarfs • Very little mass is ejected by a nova, so it will not affect the type of stellar remnant left behind (which will invariably be a white dwarf.) • Novae can increase brightness by 10,000 times. • Some novae repeat themselves, becoming what are called recurrent novae. Mechanism of Nova Production • Novae occur in binary systems between a red giant and a white dwarf. • White dwarf is formed by planetary nebula. • Novae don’t produce white dwarfs. -
Metadata of the Chapter That Will Be Visualized Online
Metadata of the chapter that will be visualized online Chapter Title Binary Systems and Their Nuclear Explosions Copyright Year 2018 Copyright Holder The Author(s) Author Family Name Isern Particle Given Name Jordi Suffix Organization Institute of Space Sciences (ICE, CSIC) Address Barcelona, Spain Organization Institut d’Estudis Espacials de Catalunya (IEEC) Address Barcelona, Spain Email [email protected] Corresponding Author Family Name Hernanz Particle Given Name Margarita Suffix Organization Institute of Space Sciences (ICE, CSIC) Address Barcelona, Spain Organization Institut d’Estudis Espacials de Catalunya (IEEC) Address Barcelona, Spain Email [email protected] Author Family Name José Particle Given Name Jordi Suffix Organization Universitat Politècnica de Catalunya (UPC) Address Barcelona, Spain Organization Institut d’Estudis Espacials de Catalunya (IEEC) Address Barcelona, Spain Email [email protected] Abstract The nuclear energy supply of a typical star like the Sun would be ∼ 1052 erg if all the hydrogen could be incinerated into iron peak elements. Chapter 5 1 Binary Systems and Their Nuclear 2 Explosions 3 Jordi Isern, Margarita Hernanz, and Jordi José 4 5.1 Accretion onto Compact Objects and Thermonuclear 5 Runaways 6 The nuclear energy supply of a typical star like the Sun would be ∼1052 erg if all 7 the hydrogen could be incinerated into iron peak elements. Since the gravitational 8 binding energy is ∼1049 erg, it is evident that the nuclear energy content is more 9 than enough to blow up the Sun. However, stars are stable thanks to the fact that their 10 matter obeys the equation of state of a classical ideal gas that acts as a thermostat: if 11 some energy is released as a consequence of a thermal fluctuation, the gas expands, 12 the temperature drops and the instability is quenched. -
Fundamentals of Stellar Evolution Theory: Understanding the HRD
Fundamentals of Stellar Evolution Theory: Understanding the HRD By C E S A R E C H I O S I Department of Astronomy, University of Padua, Vicolo Osservatorio 5, 35122 Padua, Italy Published in: "Stellar Astrophysics for the Local Group: a First Step to the Universe" VIII Canary Islands Winter School Cambridge University Press 25 March, 1997 Abstract. We summarize the results of stellar evolution theory for single stars that have been obtained over the last two decades, and compare these results with the observations. We discuss in particular the effect of mass loss by stellar winds during the various evolutionary stages of stars that are affected by this phenomenon. In addition, we focus on the problem of mixing in stellar interiors calling attention on weak aspects of current formulations and presenting plausible alternatives. Finally, we survey some applications of stellar models to several areas of modern astrophysics. 1. Introduction The major goal of stellar evolution theory is the interpretation and reproduction of the Hertzsprung-Russell Diagram (HRD) of stars in different astrophysical environments: solar vicinity, star clusters of the Milky Way and nearby galaxies, fields in external galaxies. The HRD of star clusters, in virtue of the small spread in age and composition of the component stars, is the classical template to which stellar models are compared. If the sample of stars is properly chosen from the point of view of completeness, even the shortest lived evolutionary phases can be tested. The HRD of field stars, those in external galaxies in particular, contains much information on the past star formation history. -
The Time of Perihelion Passage and the Longitude of Perihelion of Nemesis
The Time of Perihelion Passage and the Longitude of Perihelion of Nemesis Glen W. Deen 820 Baxter Drive, Plano, TX 75025 phone (972) 517-6980, e-mail [email protected] Natural Philosophy Alliance Conference Albuquerque, N.M., April 9, 2008 Abstract If Nemesis, a hypothetical solar companion star, periodically passes through the asteroid belt, it should have perturbed the orbits of the planets substantially, especially near times of perihelion passage. Yet almost no such perturbations have been detected. This can be explained if Nemesis is comprised of two stars with complementary orbits such that their perturbing accelerations tend to cancel at the Sun. If these orbits are also inclined by 90° to the ecliptic plane, the planet orbit perturbations could have been minimal even if acceleration cancellation was not perfect. This would be especially true for planets that were all on the opposite side of the Sun from Nemesis during the passage. With this in mind, a search was made for significant planet alignments. On July 5, 2079 Mercury, Earth, Mars+180°, and Jupiter will align with each other at a mean polar longitude of 102.161°±0.206°. Nemesis A, a brown dwarf star, is expected to approach from the south and arrive 180° away at a perihelion longitude of 282.161°±0.206° and at a perihelion distance of 3.971 AU, the 3/2 resonance with Jupiter at that time. On July 13, 2079 Saturn, Uranus, and Neptune+180° will align at a mean polar longitude of 299.155°±0.008°. Nemesis B, a white dwarf star, is expected to approach from the north and arrive at that same longitude and at a perihelion distance of 67.25 AU, outside the Kuiper Belt. -
Colliding Stars Spark Rush to Solve Cosmic Mysteries Stellar Collision Confirms Theoretical Predictions About the Periodic Table
Colliding stars spark rush to solve cosmic mysteries Stellar collision confirms theoretical predictions about the periodic table. • Davide Castelvecchi Neutron stars set to open their heavy hearts The collision generated the strongest and longest-lasting gravitational-wave signal ever seen on Earth. And the visible-light signal generated during the collision closely matches predictions made in recent years by theoretical astrophysicists, who hold that many elements of the periodic table that are heavier than iron are formed as a result of such stellar collisions. Neutron-star mergers are also thought to trigger previously mysterious short γ-ray bursts, a hypothesis that now also seems to have been confirmed. Astronomers have good reasons to believe that they are looking at the same source of both the gravitational waves and the short γ-ray bursts, says Cole Miller, an astronomer at the University of Maryland in College Park, who was not involved in the research but who has seen some of the papers ahead of their publication. Bright object The event was detected on Earth on 17 August, and triggered weeks of febrile, round-the-clock activity on all 7 continents, as more than 70 teams of researchers scrambled to observe the aftermath. The collision was felt first as a space-time tremor by the Laser Interferometer Gravitational-wave Observatory (LIGO) in the United States and by its Italy-based counterpart Virgo, and seen seconds afterwards as a smattering of high-energy photons by NASA’s Fermi Gamma-ray Space Telescope. Global networks of small telescopes will chase companion signals of gravitational waves Alerted by the LIGO–Virgo team, astronomers then raced to find and study what was seen as a bright object in the sky using telescopes big and small, famous and obscure, on land and in orbit, and spanning the spectrum of electromagnetic radiation, from radio waves to X-rays. -
N-Body Techniques for Astrophysics: Lecture 4 – STARLAB
Michela Mapelli N-body techniques for astrophysics: Lecture 4 – STARLAB PhD School in Astrophysics, University of Padova November 19-30, 2018 Michela Mapelli N-body techniques for astrophysics: Lecture 4 – STARLAB MOST IMPORTANT INGREDIENT: stay calm, breath, don't panic, don't kill yourself, don't kill your office mates PhD School in Astrophysics, University of Padova November 19-30, 2018 OUTLINE: 1* definition and structure of starlab http://www.sns.ias.edu/~starlab/overview/ http://www.sns.ias.edu/~starlab/structure/ 2* the dynamics: KIRA http://www.sns.ias.edu/~starlab/kira/ 3* the stellar evolution: SEBA 4* the outputs http://www.sns.ias.edu/~starlab/internals/ 5* compilation and installation 6* writing initial conditions http://www.sns.ias.edu/~starlab/examples/ 7* running kira 8* visualize outputs 1) definition and structure of starlab http://www.sns.ias.edu/~starlab/ * Software environment: multiple codes to generate, evolve and analyze a collisional system (such as a star cluster) They can be combined * Tools to Monte Carlo generate initial conditions (e.g. makeplummer) Evolve stars and binaries via population synthesis (e.g. SeBa) Evolve collisional dynamics (e.g. kira) Analyze outputs (e.g. xstarplot) * Collisional dynamics is evolved through HERMITE SCHEME with block time steps: example of code adopting tools described in lecture 3 1) definition and structure of starlab http://www.sns.ias.edu/~starlab/structure/ - CLASS: description of structure+ its functions - an OBJECT belongs to a class if it is DEFINED as member of the class → star a; EACH PARTICLE + root belongs to the node class (include/node.h) class node { static node* root; // Global address of the root node. -
Gamma Ray Bursts from Stellar Collisions
Gamma Ray Bursts from Stellar Collisions Brad M.S. Hansen & Chigurupati Murali Canadian Institute for Theoretical Astrophysics University of Toronto, Toronto, ON M5S 3H8, Canada Received ; accepted arXiv:astro-ph/9806256v1 18 Jun 1998 –2– ABSTRACT We propose that the cosmological gamma ray bursts arise from the collapse of neutron stars to black holes triggered by collisions or mergers with main sequence stars. This scenario represents a cosmological history qualitatively different from most previous theories because it contains a significant contribution from an old stellar population, namely the globular clusters. Furthermore, the gas poor central regions of globular clusters provide an ideal environment for the generation of the recently confirmed afterglows via the fireball scenario. Collisions resulting from neutron star birth kicks in close binaries may also contribute to the overall rate and should lead to associations between some gamma ray bursts and supernovae of type Ib/c. Subject headings: stars:neutron–supernovae:general–globular clusters:general– gamma rays:bursts– Galaxy:evolution –3– 1. Introduction The detection of X-ray, optical and radio afterglows from gamma-ray burst events (Costa et al 1997; van Paradijs et al 1997, Sahu et al 1997; Frail et al 1997) and concommitant redshifts (Metzger et al 1997) has provided strong support for the cosmological origin of the phenomenon. The success of the fireball model (Cavallo & Rees 1978; Rees & Meszaros 1992; Meszaros & Rees 1993) is largely independent of the origin of the energy, requiring only an energetic and baryon-poor event confined to small scales, thereby giving rise to a relativistic and optically thick outflow. -
Frederic A. Rasio — Publication List
Frederic A. Rasio | Publication List December 30, 2010 PUBLICATIONS Publications in refereed journals are marked with a ∗ following the number; invited conference papers are marked with a + ; invited reviews are marked with a # . The twenty most cited papers are highlighted with their title in boldface. The number of citations reported by the NASA Astrophysics Data System is given in square brackets following the title. An online version of this list, including links to electronic copies of all papers in PDF format and full citation information, is available at http://www.astro.northwestern.edu/rasio/. 1. Solving the Collisionless Boltzmann Equation in General Relativity. Rasio, F.A., Shapiro, S.L., & Teukolsky, S.A. 1989, in Dynamics of Dense Stellar Systems, ed. D. Merritt (Cambridge: Cam- bridge Univ. Press), 121{130. 2. ∗ On the Existence of Stable Relativistic Star Clusters with Arbitrarily Large Central Redshifts. Rasio, F.A., Shapiro, S.L., & Teukolsky, S.A. 1989, Astrophysical Journal Letters, 336, L63{L66. 3. ∗ What is Causing the Eclipse in the Millisecond Binary Pulsar? Rasio, F.A., Shapiro, S.L., & Teukolsky, S.A. 1989, Astrophysical Journal, 342, 934{939. 4. ∗ Solving the Vlasov Equation in General Relativity. Rasio, F.A., Shapiro, S.L., & Teukolsky, S.A. 1989, Astrophysical Journal, 344, 146{157. 5. ∗ Encounters between Compact Stars and Red Giants in Dense Stellar Systems. Rasio, F.A., & Shapiro, S.L. 1990, Astrophysical Journal, 354, 201{210. 6. ∗ Eclipse Mechanisms for Binary Pulsars. Rasio, F.A., Shapiro, S.L., & Teukolsky, S.A. 1991, Astronomy & Astrophysics, 241, L25{L28. 7. ∗ Collisions of Giant Stars with Compact Objects: Hydrodynamical Calculations [117]. -
Ch 06-Phys--Star Death & H-R Di
Ch. 6--Stars and H-R Diagrams Chapter 6 THE LIFE AND DEATH OF A STAR, and THE H-R DIAGRAM A.) Hertzsprung-Russell Diagrams: 1.) The Hertzsprung-Russell diagram plots luminosity versus temperature. Aside from its primary use (i.e., if you can determine a star's surface temperature, the H-R diagram will give you its luminosity), it is a useful educational tool in the sense that it highlights in the universe order out of what would otherwise appear to be disorder. Hertzsprung-Russell diagram 2.) The basics of the H-R diagram and things you Luminosity (solar units) blue giants need to understand about and supergiants the system follow. 10,000 red giants and supergiants a.) Temperature 100 on the H-R diagram 100 R ranges from 30,000 main sun sequence degrees Kelvin to 1 sun 3000 degrees Kelvin 10 Rsun (those temperatures are plotted backward- .01 R -odd, but that's the sun red dwarfs way some white dwarfs astronomers are--a .0001 .1 Rsun little bit of physicist humor). It plots from 30,000 10,000 6000 3000 O type to M type stars (we talked about spec- Surface Temperature (degrees K) tral classification earlier). OAGMBFK Spectral Class 171 b.) The luminosity scale is expressed in terms of luminosity of the sun. That is, on a H-R diagram, L = 1 is found in the middle of the plot and denotes the sun's position on the diagram. c.) Luminosity on the H-R diagram ranges from 10-4 to 104. Again, 1 denotes the luminosity of the sun.