Download or read book The Diffuse Galactic Gamma Ray Emission Model for GLAST LAT written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffuse emission from the Milky Way dominates the gamma-ray sky. About 80% of the high-energy luminosity of the Milky Way comes from processes in the interstellar medium. The Galactic diffuse emission traces interactions of energetic particles, primarily protons and electrons, with the interstellar gas and radiation field, thus delivering information about cosmic-ray spectra and interstellar mass in distant locations. Additionally, the Galactic diffuse emission is the celestial foreground for the study of gamma-ray point sources and the extragalactic diffuse gamma-ray emission. We will report on the latest developments in the modeling of the Galactic diffuse emission, which will be used for the Gamma Ray Large Area Space Telescope (GLAST) investigations.
Download or read book Developing the Galactic Diffuse Emission Model for the GLAST Large Area Telescope written by and published by . This book was released on 2007 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffuse emission is produced in energetic cosmic ray (CR) interactions, mainly protons and electrons, with the interstellar gas and radiation field and contains the information about particle spectra in distant regions of the Galaxy. It may also contain information about exotic processes such as dark matter annihilation, black hole evaporation etc. A model of the diffuse emission is important for determination of the source positions and spectra. Calculation of the Galactic diffuse continuum g-ray emission requires a model for CR propagation as the first step. Such a model is based on theory of particle transport in the interstellar medium as well as on many kinds of data provided by different experiments in Astrophysics and Particle and Nuclear Physics. Such data include: secondary particle and isotopic production cross sections, total interaction nuclear cross sections and lifetimes of radioactive species, gas mass calibrations and gas distribution in the Galaxy (H2, H I, H II), interstellar radiation field, CR source distribution and particle spectra at the sources, magnetic field, energy losses, g-ray and synchrotron production mechanisms, and many other issues. We are continuously improving the GALPROP model and the code to keep up with a flow of new data. Improvement in any field may affect the Galactic diffuse continuum g-ray emission model used as a background model by the GLAST LAT instrument. Here we report about the latest improvements of the GALPROP and the diffuse emission model.
Download or read book Re examining the Diffuse Gamma ray Excess from the Inner Galaxy written by Brian Baughman and published by . This book was released on 2007 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling the Galactic Diffuse Gamma ray Emission written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The diffuse gamma-ray emission in our Galaxy is produced by highly energetic electrons interacting mainly with radiation fields through inverse Compton scattering or in interactions with interstellar matter through Bremsstrahlung. Furthermore, protons also interact with the interstellar matter and produce gamma-rays through the production of pion particles and their subsequent decay. The energy range of gamma-ray emission covers the domain from a few MeV (1 MeV = 106 eV) up to energies> 100 TeV (1 TeV = 1012 eV). In this work a model to predict the diffuse gamma-ray emission is presented. The general idea of this model is to simulate a population of galactic sources, which accelerate protons and electrons, distributed according to the populations of supernova remnants and pulsars at radio wavelengths. Through the previously mentioned interaction processes, the diffuse gamma-ray emission spectrum can be predicted for different regions of the Galaxy. The goal of this thesis is to produce the spectrum of diffuse gamma-ray emission for the two different regions of the Galaxy at l=344 longitude, b=0 latitude and at l=344 longitude, b=4 latitude.
Download or read book Cosmic Gamma Ray Sources written by K.S. Cheng and published by Springer Science & Business Media. This book was released on 2012-11-03 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gamma-ray astronomy has undergone an enormous progress in the last 15 years. The success of satellite experiments like NASA's Comp ton Gamma-Ray Observatory and ESA's INTEGRAL mission, as well as of ground-based instruments have open new views into the high-energy Universe. Different classes of cosmic gamma-ray sources have been now detected at different energies, in addition to young radio pulsars and gamma-ray bursts, the classical ones. The new sources include radio quiet pulsars, microquasars, supernova remnants, starburst galaxies, ra dio galaxies, flat-spectrum radio quasars, and BL Lacertae objects. A large number of unidentified sources strongly suggests that this brief enumeration is far from complete. Gamma-ray bursts are now estab lished as extragalactic sources with tremendous energy output. There is accumulating evidence supporting the idea that massive stars and star forming regions can accelerate charged particles up to relativistic ener gies making them gamma-ray sources. Gamma-ray astronomy has also proved to be a powerful tool for cosmology imposing constraints to the background photon fields that can absorb the gamma-ray flux from dis tant sources. All this has profound implications for our current ideas about how particles are accelerated and transported in both the local and distant U niverse. The evolution of our knowledge on the gamma-ray sky has been so fast that is not easy for the non-specialist scientist and the graduate student to be aware of the full potential of this field or to grasp the fundamentals of a given topic in order to attempt some original contribution.
Download or read book The Nature of Unidentified Galactic High Energy Gamma Ray Sources written by Alberto Carramiñana and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Energetic Gamma-Ray Experiment Telescope (EGRET) instru ment on the Compton Gamma-Ray Observatory left as a legacy its Third Catalog of High Energy Gamma-Ray Sources, whose detections include a large number of blazars, some pulsars, the Large Magellanic Cloud and a solar flare. Most of the newly discovered objects - a majority of the catalog -are unidentified sources, with a clearly predominant Galactic population. Are all these radio-quiet pulsars, like Geminga, or is there a novel type of celestial object, awaiting identification? In spite of the limited angular resolution provided by EGRET and COMPTEL, there is still much to learn about unidentified ,-ray sources: correlation studies, multiwavelength observations and theoretical work can provide valuable clues, specially if these efforts are carried out in a coordinated manner. The aim of this workshop, held from October 9 to 11, 2000, at the Instituto N acional de Astrofisica, Optica y Electronica, at Tonantzintla, Mexico, was to gather experts on the subject, including observational as tronomers specialized in other regions of the electromagnetic spectrum, in an effort to address the question of the Nature of Galactic high-energy gamma-ray sources, both from the theoretical and observational perspec tive, and elaborate schemes for future identification studies which can make use of existing and forthcoming facilities.
Download or read book Future GeV Gamma Ray Missions and New Discovery Potential written by T. Kamae and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Future GeV {gamma}-ray missions, efforts to improve the diffuse {gamma}-ray emission modeling, and possible exploitation of temporal variability for source characterization are reviewed. GLAST-LAT with its improved point-spread-function is expected to attain mCrab sensitivity, facilitate identification of {gamma}-ray sources with those in other wavelength, and discover new source classes. However these new sources are likely to suffer from the Galactic diffuse background and/or the source confusion. Accurate modeling of the background will be essential to enhance discovery potential for Galactic sources and full exploitation of temporal variability will allow source identification even in highly confusing environment. GALPROP by Strong and Moskalenko provides a platform on which models and measurements on the cosmic ray, ISM and radiation field can be combined in a consistent way. An up-to-date high-energy pp interaction modeling has reduced the ''GeV Excess'' in the diffuse {gamma}-ray spectrum significantly. Updating GALPROP with this interaction modeling as well as with other improvements will be needed before GLAST goes to orbit. The new temporal domain will be fully explored by GLAST-LAT as a new way to identify and characterize AGNs at cosmological distance.
Download or read book Cosmic Mysteries written by Time-Life Books and published by Time Life Education. This book was released on 1990 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides information and explores theories behind such phenomena as eclipses, black holes, gamma ray bursts, star births, and quasars
Download or read book Understanding Limitations in the Determination of the Diffuse Galactic Gamma ray Emission written by A. W. Strong and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We discuss uncertainties and possible sources of errors associated with the determination of the diffuse Galactic {gamma}-ray emission using the EGRET data. Most of the issues will be relevant also in the GLAST era. The focus here is on issues that impact evaluation of dark matter annihilation signals against the diffuse {gamma}-ray emission of the Milky Way.
Download or read book Science With The New Generation Of High Energy Gamma ray Experiments The Variable Gamma ray Sources Their Identifications And Counterparts Proceedings Of The Fourth Workshop written by Marco Maria Massai and published by World Scientific. This book was released on 2007-10-02 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 Diffuse Gamm ray Emission written by and published by . This book was released on 2007 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Galactic diffuse emission is potentially able to reveal much about the sources and propagation of cosmic rays (CR), their spectra and intensities in distant locations. It can possibly unveil WIMP dark matter (DM) through its annihilation signatures. The extragalactic background may provide vital information about the early stages of the universe, neutralino annihilation, and unresolved sources (blazars) and their cosmological evolution. The g-ray instrument EGRET on the CGRO contributed much to the exploration of the Galactic diffuse emission. The new NASA Gamma-ray Large Area Space Telescope (GLAST) is scheduled for launch in 2007; study of the diffuse g-ray emission is one of the priority goals. We describe current understanding of the diffuse emission and its potential for future discoveries.
Download or read book Particles and Astrophysics written by Maurizio Spurio and published by Springer. This book was released on 2014-10-06 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an introduction to “multi-messenger” astrophysics. It covers the many different aspects connecting particle physics with astrophysics and cosmology and introduces astrophysics using numerous experimental findings recently obtained through the study of high-energy particles. Taking a systematic approach, it comprehensively presents experimental aspects from the most advanced laboratories and detectors, as well as the theoretical background. The book is aimed at graduate students and post-graduate researchers with a basic understanding of particle and nuclear physics. It will also be of interest to particle physicists working in accelerator/collider physics who are keen to understand the mechanisms of the largest accelerators in the Universe. The book draws on the extensive lecturing experience of Professor Maurizio Spurio from the University of Bologna.
Download or read book Gamma Ray Astrophysics written by Carl E. Fichtel and published by . This book was released on 1981 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Discovery of Localized TeV Gamma ray Sources and Diffuse TeV Gamma ray Emission from the Galactic Plane with Milagro Using a New Background Rejection Technique written by Aws Ahmad Abdo and published by . This book was released on 2007 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Measurement of the Spatial Distribution of Diffuse TeV Gamma Ray Emission from the Galactic Plane with Milagro written by and published by . This book was released on 2008 with total page 15 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 Astronomy with Radioactivities written by Roland Diehl and published by Springer Science & Business Media. This book was released on 2010-10-02 with total page 577 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the reader to the field of nuclear astrophysics, i.e. the acquisition and reading of measurements on unstable isotopes in different parts of the universe. The authors explain the role of radioactivities in astrophysics, discuss specific sources of cosmic isotopes and in which special regions they can be observed. More specifically, the authors address stars of different types, stellar explosions which terminate stellar evolutions, and other explosions triggered by mass transfers and instabilities in binary stars. They also address nuclear reactions and transport processes in interstellar space, in the contexts of cosmic rays and of chemical evolution. A special chapter is dedicated to the solar system which even provides material samples. The book also contains a description of key tools which astrophysicists employ in those particular studies and a glossary of key terms in astronomy with radioactivities.
