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Related papers: Supernovae and Positron Annihilation

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Microquasars are stellar-mass black holes accreting matter from a companion star and ejecting plasma jets at almost the speed of light. They are analogues of quasars that contain supermassive black holes of $10^6$ to $10^{10}$ solar masses.…

Estimates made in the 1970's indicated that a supernova occurring within tens of parsecs of Earth could have significant effects on the ozone layer. Since that time, improved tools for detailed modeling of atmospheric chemistry have been…

Supernova (SN) explosions are a major feedback mechanism regulating star formation in galaxies through their momentum input. We review the observations of SNRs in radiative stages in the Milky Way to validate the theoretical results on the…

Astrophysics of Galaxies · Physics 2020-12-16 Bon-Chul Koo , Chang-Goo Kim , Sangwook Park , Eve C. Ostriker

Both diffuse high energy gamma-rays and an extended electron-positron annihilation line emission have been observed in the Galactic Center (GC) region. Although X-ray observations indicate that the galactic black hole Sgr A$^*$ is inactive…

Astrophysics · Physics 2009-11-11 K. S. Cheng , D. O. Chernyshov , V. A. Dogiel

A precise and model-independent determination of the neutron distribution radius $R_{\rm n}$ and thus the neutron skin thickness $R_{\rm skin}$ of atomic nuclei is of fundamental importance in nuclear physics, particle physics and…

Nuclear Theory · Physics 2023-06-16 Xu-Run Huang , Lie-Wen Chen

In addition to long-lived radioactive nuclei like U and Th isotopes, which have been used to measure the age of the Galaxy, also radioactive nuclei with half-lives between 0.1 and 100 million years (short-lived radionuclides, SLRs) were…

Solar and Stellar Astrophysics · Physics 2021-09-30 M. Lugaro , U. Ott , Á. Kereszturi

The favored progenitor model for Gamma-ray Bursts (GRBs) with Supernova (SN) association is the core collapse of massive stars. One possible outcome of such a collapse is a rapidly spinning, strongly magnetized neutron star ("magnetar"). We…

High Energy Astrophysical Phenomena · Physics 2018-08-08 Hou-Jun Lü , Lin Lan , Bing Zhang , En-Wei Liang , David Alexander Kann , Shen-Shi Du , Jun Shen

The 511 keV positron annihilation emission remains a mysterious component of the high energy emission of our Galaxy. Its study was one of the key scientific objective of the SPI spectrometer on-board the INTEGRAL satellite. In fact, a lot…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Laurent Bouchet , Jean-Pierre Roques , Elisabeth Jourdain

The problem of extinction is the most important issue to be dealt with in the process of obtaining true absolute magnitudes of core-collapse (including stripped-envelope) supernovae (SNe). The plane-parallel model, widely used in the past,…

Astrophysics · Physics 2008-03-12 Dusan Onic , Bojan Arbutina , Dejan Urosevic

The infrared is a key wavelength regime for probing the dusty, obscured nuclear regions of active galaxies. We present results from an infrared study of 87 nearby Seyfert galaxies using the Spitzer Space Telescope and ground-based…

It is widely thought that core-collapse supernovae (CCSNe), the explosions of massive stars following the collapse of the stars' iron cores, is obtained due to energy deposition by neutrinos. So far, this scenario was not demonstrated from…

High Energy Astrophysical Phenomena · Physics 2015-02-12 Doron Kushnir

Resonant positron annihilation on atomic electrons provides a powerful method to search for light new particles coupled to $e^+e^-$. Reliable estimates of production rates require a detailed characterization of electron momentum…

High Energy Physics - Phenomenology · Physics 2024-10-11 Fernando Arias-Aragón , Luc Darmé , Giovanni Grilli di Cortona , Enrico Nardi

General relativistic calculations are made of neutrino-antineutrino annihilation into electron-positron pairs near the surface of a neutron star. It is found that the efficiency of this process is enhanced over the Newtonian values up to a…

Astrophysics · Physics 2009-10-31 Jay D. Salmonson , James R. Wilson

The observed distribution of neutron star (NS) masses reflects the physics of core-collapse supernova explosions and the structure of the massive stars that produce them at the end of their evolution. We present a Bayesian analysis that…

Solar and Stellar Astrophysics · Physics 2012-07-25 Ondrej Pejcha , Todd A. Thompson , Christopher S. Kochanek

Following merger, a neutron star (NS) binary can produce roughly one of three different outcomes: (1) a stable NS, (2) a black hole (BH), or (3) a supra-massive, rotationally-supported NS, which then collapses to a BH following angular…

High Energy Astrophysical Phenomena · Physics 2017-08-02 Anthony L. Piro , Bruno Giacomazzo , Rosalba Perna

We argue that the decays of radioactive nuclei related to $^{44}$Ti and $^{56}$Ni ejected during supernova explosions can provide a vast pool of mildly relativistic positrons and electrons which are further accelerated to ultrarelativistic…

Astrophysics of Galaxies · Physics 2013-05-29 V. N. Zirakashvili , F. A. Aharonian

Stars of ~8-100 solar masses end their lives as core-collapse supernovae (SNe). In the process they emit a powerful burst of neutrinos, produce a variety of elements, and leave behind either a neutron star or a black hole. The wide mass…

High Energy Astrophysical Phenomena · Physics 2018-01-30 Yong-Zhong Qian

Supernova remnants (SNRs) offer the means to study SN explosions, dynamics, and shocks at sub-parsec scales. X-ray observations probe the hot metals synthesized in the explosion and the TeV electrons accelerated by the shocks, and thus they…

We have computed new estimates of the local rates of supernovae (SNe) adding the updated log of Evans' visual search to our SN search database. In this way, we have accumulated the largest SN statistics ever assembled for this purpose. The…

Astrophysics · Physics 2008-11-26 E. Cappellaro , R. Evans , M. Turatto

The bulk of the extragalactic background between 10 keV and 10 GeV is likely to be explained by the emission of Seyfert galaxies, type Ia supernovae, and blazars. However, as revealed by the INTEGRAL satellite, the bulge of our galaxy is an…

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