Download or read book A New Method for the Reconstruction of Very high energy Gamma ray Spectra and Application to Galactic Cosmic ray Accelerators written by Milton Virgílio Fernandes and published by . This book was released on 2014 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gamma ray and Neutrino Signatures of Galactic Cosmic ray Accelerators written by Silvia Celli and published by Springer Nature. This book was released on 2019-12-17 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Science With The New Generation Of High Energy Gamma ray Experiments Proceedings Of The Third Workshop written by Oriana Mansutti and published by World Scientific. This book was released on 2006-05-30 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Science with the New Generation of High Energy Gamma Ray Experiments written by Claudia Cecchi and published by American Institute of Physics. This book was released on 2010-04-27 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Proceedings of the Fourth Workshop on Science with the New Generation of High Energy Gamma Ray Experiments written by Marco Maria Massai and published by World Scientific. This book was released on 2007 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book The Production of Cosmic Gamma Rays in Interstellar and Intergalactic Cosmic ray Collisions written by Floyd William Stecker and published by . This book was released on 1967 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Multi Messenger Approach to High Energy Gamma Ray Sources written by Josep M. Paredes and published by Springer Science & Business Media. This book was released on 2007-11-12 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Development of an Advanced Gamma hadron Separation Technique and Application to Particular Gamma ray Sources with H E S S written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Multiwavelength Approach to Unidentified Gamma Ray Sources written by K.S. Cheng and published by Springer Science & Business Media. This book was released on 2005-12-05 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nearly one half of the point-like gamma-ray sources detected by EGRET instrument of the late Compton satellite are still defeating our attempts at identifying them. To establish the origin and nature of these enigmatic sources has become a major problem of current high-energy astrophysics. The second workshop on Multiwavelength Approach to Unidentified Gamma-ray Sources intends to shed new and fresh light on the problem of the nature of the unidentified gamma-ray sources. The proceedings contain 46 contributed papers in this subject, which cover theoretical models on gamma-ray sources as well as the best multiwavelength strategies for the identification of the promising candidates. The topics of this conference also include energetic phenomena occurring both in galactic and extragalactic scenarios, phenomena that might lead to the appearance of what we have called high-energy unidentified sources. The book will be of interest for all active researchers in the high-energy astrophysics and related research areas as well as for scientists and graduate students interested in understanding the recent progress in high-energy astrophysics.
Download or read book Tracing the Most Powerful Galactic Cosmic ray Accelerators with the HAWC Observatory written by and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Science with the New Generation of High Energy Gamma Ray Experiments written by Denis Bastieri and published by American Institute of Physics. This book was released on 2009-05-15 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992-06 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutrino Astrophysics with the ANTARES Telescope written by Vladimir Kulikovskiy and published by Springer. This book was released on 2015-06-22 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is devoted to ANTARES, the first underwater neutrino telescope in the Mediterranean sea. As the main scientific analysis, a search for high-energy neutrino emission from the region of the Fermi bubbles has been performed using data from the ANTARES detector. A method for the background estimation using off-zones has been developed specially for this measurement. A new likelihood for the limits calculation which treats both observations in the on-zone and in the off-zone in the similar way and also includes different systematic uncertainties has been constructed. The analysis of 2008–2011 ANTARES data yielded a 1.2 σ excess of events in the Fermi bubble regions, compatible with the no-signal hypothesis. For the optimistic case of no energy cutoff in the flux, the upper limit is within a factor of three of the prediction of the purely hadronic model based on the measured gamma-ray flux. The sensitivity improves as more data are accumulated (more than 65% gain in the sensitivity is expected once 2012–2016 data are added to the analysis).
Download or read book Proceedings Of The 29th International Conference On High Energy Physics Ichep 98 In 2 Volumes written by Alan Astbury and published by World Scientific. This book was released on 1999-06-11 with total page 1899 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings consist of plenary rapporteur talks covering topics of major interest to the high energy physics community and parallel sessions papers which describe recent research results and future plans.
Download or read book Gamma ray Studies of the Young Shell type SNR RX J1713 7 3946 written by Simone Federici and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most significant current discussions in Astrophysics relates to the origin of high-energy cosmic rays. According to our current knowledge, the abundance distribution of the elements in cosmic rays at their point of origin indicates, within plausible error limits, that they were initially formed by nuclear processes in the interiors of stars. It is also believed that their energy distribution up to 1018 eV has Galactic origins. But even though the knowledge about potential sources of cosmic rays is quite poor above " 1015 eV, that is the "knee" of the cosmic-ray spectrum, up to the knee there seems to be a wide consensus that supernova remnants are the most likely candidates. Evidence of this comes from observations of non-thermal X-ray radiation, requiring synchrotron electrons with energies up to 1014 eV, exactly in the remnant of supernovae. To date, however, there is not conclusive evidence that they produce nuclei, the dominant component of cosmic rays, in addition to electrons. In light of this dearth of evidence, [gamma]-ray observations from supernova remnants can offer the most promising direct way to confirm whether or not these astrophysical objects are indeed the main source of cosmic-ray nuclei below the knee. Recent observations with space- and ground-based observatories have established shell-type supernova remnants as GeV-to- TeV [gamma]-ray sources. The interpretation of these observations is however complicated by the different radiation processes, leptonic and hadronic, that can produce similar fluxes in this energy band rendering ambiguous the nature of the emission itself. The aim of this work is to develop a deeper understanding of these radiation processes from a particular shell-type supernova remnant, namely RX J1713.7-3946, using observations of the LAT instrument onboard the Fermi Gamma-Ray Space Telescope. Furthermore, to obtain accurate spectra and morphology maps of the emission associated with this supernova remnant, an improved model of the diffuse Galactic [gamma]-ray emission background is developed. The analyses of RX J1713.7-3946 carried out with this improved background show that the hard Fermi-LAT spectrum cannot be ascribed to the hadronic emission, leading thus to the conclusion that the leptonic scenario is instead the most natural picture for the high-energy [gamma]-ray emission of RX J1713.7-3946. The leptonic scenario however does not rule out the possibility that cosmic-ray nuclei are accelerated in this supernova remnant, but it suggests that the ambient density may not be high enough to produce a significant hadronic [gamma]-ray emission. Further investigations involving other supernova remnants using the improved back- ground developed in this work could allow compelling population studies, and hence prove or disprove the origin of Galactic cosmic-ray nuclei in these astrophysical objects. A break- through regarding the identification of the radiation mechanisms could be lastly achieved with a new generation of instruments such as CTA.
Download or read book Probing the Spatial and Spectral Distribution of Galactic Cosmic Rays with High energy Gamma rays written by Giada Peron and published by . This book was released on 2020* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sixteenth Marcel Grossmann Meeting The On Recent Developments In Theoretical And Experimental General Relativity Astrophysics And Relativistic Field Theories Proceedings Of The Mg16 Meeting On General Relativity In 4 Volumes written by Remo Ruffini and published by World Scientific. This book was released on 2022-12-15 with total page 4880 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings of MG16 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting included 46 plenary presentations, 3 public lectures, 5 round tables and 81 parallel sessions arranged during the intense six-day online meeting. All talks were recorded and are available on the ICRANet YouTube channel at the following link: www.icranet.org/video_mg16.These proceedings are a representative sample of the very many contributions made at the meeting. They contain 383 papers, among which 14 come from the plenary sessions.The material represented in these proceedings cover the following topics: accretion, active galactic nuclei, alternative theories of gravity, black holes (theory, observations and experiments), binaries, boson stars, cosmic microwave background, cosmic strings, dark energy and large scale structure, dark matter, education, exact solutions, early universe, fundamental interactions and stellar evolution, fast transients, gravitational waves, high energy physics, history of relativity, neutron stars, precision tests, quantum gravity, strong fields, and white dwarf; all of them represented by a large number of contributions.The online e-proceedings are published in an open access format.
