Author : Milton Virgílio Fernandes
Publisher :
Page : 221 pages
File Size : 38,71 MB
Release : 2014
Category :
ISBN :
Author : Silvia Celli
Publisher : Springer Nature
Page : 264 pages
File Size : 15,83 MB
Release : 2019-12-17
Category : Science
ISBN : 3030331245
This book addresses three “hot” topics concerning the general problem of the origin of Galactic cosmic rays, namely (1) the acceleration, propagation, and radiation of particles in supernova remnants; (2) very high energy neutrinos from the Galactic Center; and (3) the potential held by the next-generation gamma-ray and neutrino detectors CTA and KM3NeT for studying extended non-thermal sources in the Galaxy. The topics are intrinsically connected to determining the nature (“hadronic or leptonic?”) of gamma-ray emissions from young and middle-aged supernova remnants and the search for cosmic-ray PeVatrons. The results and conclusions provided here are based on extensive analytical and numerical simulations, which are formulated and presented in a straightforward format that can be readily used in the interpretations of gamma-ray and neutrino observations, as well as for confident predictions for future measurements.
Author : Oriana Mansutti
Publisher : World Scientific
Page : 228 pages
File Size : 20,30 MB
Release : 2006-05-30
Category : Science
ISBN : 981447794X
The contributions in this volume provide a snapshot of the latest research and future plans for space-borne and ground-based experiments dedicated to the observation of the gamma-ray sky. The articles are authored by both seasoned veterans of the first dedicated gamma-ray missions, and young scientists entering the fascinating field of gamma-ray astrophysics.With the advent of gamma-ray instrumentation on spacecraft and large and sensitive ground-based detectors, new and unexpected phenomena have been discovered, such as gamma-ray bursts and gamma-ray emission from blazars. The immense vitality of the field in the current “post-EGRET era” is witnessed by the numerous ongoing and forthcoming gamma-ray experiments documented here, complementary to various cosmic-ray, neutrino, astroparticle and X-ray projects.
Author : Claudia Cecchi
Publisher : American Institute of Physics
Page : 0 pages
File Size : 36,86 MB
Release : 2010-04-27
Category : Science
ISBN : 9780735407671
This book collects contributions presented in the seventh edition in a series of Workshop on High Energy Gamma-ray Experiments. The focus of the Workshop was on Gamma-ray Physics in the LHC Era. In order to understand the origin of the Universe reaserchers are nowadays using two powerful and complementary approaches. On one side radiation produced many years ago and now arriving to us from space, is studied with different experimental techniques. On the other one, particle accelerators can recreate in laboratory the high density high energy state present at the beginning of the Universe. Results are here presented from experiments in space, on earth and underground, regarding cosmic radiation.
Author : Marco Maria Massai
Publisher : World Scientific
Page : 251 pages
File Size : 10,24 MB
Release : 2007
Category : Science
ISBN : 9812709649
The research program in gamma-ray astronomy focuses on increasing our knowledge of the nature and origin of galactic and extragalactic gamma rays, and understanding high-energy processes in the Sun, celestial objects, interstellar medium, and extragalactic space.This book not only provides an overview of the latest research and future plans for space-borne and ground-based experiments dedicated to the observation of the gamma-ray sky, but also addresses the topic of variable gamma-ray sources from the perspective of their identification and counterparts at different wavelengths. It further gives an overview of the theory related to the most qualified emission processes that take place in these sources and of the nature of their variability.
Author : Floyd William Stecker
Publisher :
Page : 94 pages
File Size : 41,38 MB
Release : 1967
Category : Cosmic rays
ISBN :
Author : Josep M. Paredes
Publisher : Springer Science & Business Media
Page : 496 pages
File Size : 11,42 MB
Release : 2007-11-12
Category : Science
ISBN : 140206117X
This book provides a theoretical and observational overview of the state of the art of gamma-ray astrophysics, and their impact and connection with the physics of cosmic rays and neutrinos. With the aim of shedding new and fresh light on the problem of the nature of the gamma-ray sources, particularly those yet unidentified, this book summarizes contributions to a workshop that continues today.
Author :
Publisher :
Page : pages
File Size : 14,34 MB
Release :
Category :
ISBN :
The High Energy Stereoscopic system, H.E.S.S. is an array of four imaging atmospheric Cherenkov telescopes, designed for the study of non-thermal phenomena in the universe at very high energies (VHE). The sensitivity of telescope systems such as H.E.S.S. can considerably be improved by a better discrimination of the vast number of hadronic cosmic-ray background events against the very rare gamma-ray signal events. In this work, an elaborated discrimination technique - the Boosted Decision Tree method - has been developed and its capabilities in terms of gamma/hadron separation and improved sensitivity are demonstrated. In the second part, the BDT method is applied to data obtained in observations of massive star forming environments, namely the colliding wind binary [eta] Carinae, the massive stellar cluster Westerlund 1 and the Starburst galaxy NGC 253. An upper limit on the gamma-ray flux of the famous colliding wind binary system [eta] Carinae is derived and, for the first time, an alternative model for the high-energy emission observed by the Fermi satellite is presented. The detection of very extended VHE gamma-ray emission from the vicinity of Westerlund 1 is reported and thorough spectral and morphological tests are presented. Large parts of the resolved emission can be explained in a hadronic scenario, however, a decisive conclusion can not be drawn. Finally, the BDT method allowed to detect the first Starburst galaxy, namely NGC253, in VHE gamma rays. Spectral and morphological results are presented and suggest that large parts of the CR energy content are convectively and diffusively transported into the intergalactic medium.
Author :
Publisher :
Page : 0 pages
File Size : 33,42 MB
Release : 2023
Category :
ISBN :
Abstract : Since Victor Hess's groundbreaking detection of cosmic rays in the Earth's atmosphere in 1912, the origins of these charged particles have remained an enduring mystery. Recent studies suggest that these cosmic rays are accelerated beyond Peta electronvolts by powerful astrophysical sources within our own galaxy. While the cosmic rays themselves are being deflected in all directions by magnetic fields, the gamma rays produced by them, being electrically neutral, travel to the observer in a straight line. They carry crucial information, allowing us to trace cosmic-ray accelerators within our galaxy. The High Altitude Water Chrenkov (HAWC) Observatory, located on the slopes of the Sierra Negra volcano near Puebla, surveys the gamma-ray sky with a duty cycle of over 95\%. A sensitivity to gamma rays ranging from about 100 GeV to beyond 100 TeV, coupled with a 2-steradian instantaneous field of view, makes HAWC one of the premier observatories for studying the most energetic galactic gamma-ray sources. The gamma-ray source eHWC J1825-134, passing the field of view of HAWC at a zenith angle of $32^{\circ}$, is located in the brightest region above 50~TeV in the HAWC data set. This region contains several astrophysical objects, including three pulsar wind nebulae powered by fast-spinning pulsars, a young star cluster, a gamma-ray binary system, and four supernova remnant shells. All these objects are capable of accelerating charged particles and contributing to the cosmic rays detected at Earth. This dissertation focuses on in-depth morphological and spectral studies within the eHWC J1825-134 region. Through a multi-source maximum likelihood analysis, we are able to separate gamma-ray emissions from different sources: the binary system LS 5039, PSR J1826-1254 and its associated pulsar wind nebulae, and the emission source HAWC J1825-134 which is either associated with PSR J1826-1334 or a young star cluster. The gamma-ray sources LS 5039 and HAWC J1825-134 are PeVatron candidates emitting to about 200 hundred TeV at least. Additionally, two TeV halo candidates surround PSR J1826-1334 and PSR J1813-1246.
Author : Denis Bastieri
Publisher : American Institute of Physics
Page : 260 pages
File Size : 46,60 MB
Release : 2009-05-15
Category : Science
ISBN :
This is the sixth edition in a series of Workshops on High Energy Gamma-Ray Experiments, following the ones held in Perugia (2002), Bari (2004), Cividale del Friuli (2005), Elba Island (2006) and Villa Mondragone (2007). The year the focus is on the region known by the acronym VHE (Very High Energy), bridging the gap between GeV and TeV. The physics that lies in this region is of the utmost importance to improve our knowledge of many different astrophysical sources like pulsars, AGNs, GRBs, and our understanding of the main components of the Extragalactic Background Light (EBL). An update is given on the current and planned research for spaceborne and ground-based experiments dedicated to the observation of the gamma-ray sky.
