Download or read book Search for TeV Gamma Ray Sources in the Galactic Plane with the HAWC Observatory written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Searching for TeV Gamma ray Emission from Compact Binaries with the HAWC Observatory written by Chang Dong Rho and published by . This book was released on 2019 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Astrophysical sources of very-high-energy (VHE) gamma-ray radiation provide unique information about astrophysical particle acceleration and cosmic-ray production. In particular, compact binary systems, composed of a compact object (a neutron star or black hole) in orbit with a massive stellar companion, provide an ideal environment for VHE gamma-ray production. They are not only powerful particle accelerators, but they also exhibit periodic emission that makes them excellent astrophysical laboratories. However, only a handful of binary systems have ever been observed in VHE gamma rays. Partly, this is because VHE gamma-ray binaries appear to be very rare, and part is due to observational bias. Most instruments operating at TeV are pointed and must allocate time to observing many kinds of objects. The High Altitude Water Cherenkov (HAWC) Observatory, on the other hand, has high uptime (duty cycle >95%) and a wide field of view (2 sr), making it well-suited for observing transient and time-varying sources such as binaries. HAWC is also currently the only detector that is sensitive to gamma-ray photons above 10 TeV. Collected HAWC data spanning33 months between November 2014 and January 2018 are used to analyze the known and candidate VHE gamma-ray binary systems in this work. "Microquasars" are a special subclass of X-ray binaries that are also candidate VHE gamma-ray sources. Unlike other types of binaries, compact objects in microquasars accrete matter from their companion star. This process forms an accretion disk around the compact object and relativistic jets of particles are released perpendicular to the accretion disk. This feature is very similar to active galactic nuclei (AGN), only smaller in size. Given the fact that direct observation of particle acceleration in distant AGN is very challenging, microquasars grant the valuable opportunity to model similar processes using nearby objects in our own Galaxy. SS 433 is a known microquasar that has two jets ("east" and "west") terminating in radio lobes of a surrounding supernova remnant, W 50. The recent observation of SS 433 with HAWC marked the first direct evidence of gamma-ray emission from the jets of a microquasar. Using HAWC data, we have measured a VHE flux of [formula not rendered] at the jet interaction region e1 in the east lobe and [formula not rendered] in the west lobe with a combined post-trial statistical significance of 5:4. The systematic studies used to confirm the VHE gamma-ray emission at 20 TeV from the SS 433 jet interaction regions is discussed in this work, along with a brief description of the theoretical interpretation associated with the observation. The HAWC data were also used to search for gamma rays from the known VHE binaries HESS J0632+057 and LS 5039. No emission was observed from HESS J0632+057, so we compute upper limits on its flux. Emission at low statistical significance is observed from LS 5039, which is located in a crowded region of the Galactic plane and is contaminated by gamma rays from nearby extended sources. A multiple-source analysis of the region surrounding LS 5039, as well as a time-series analysis of the light curve from LS 5039, are presented. At this time, data from HAWC are not significant enough to support multi-TeV emission from LS 5039"--Pages xi-xiii.
Download or read book Gamma Rays in the 100 TeV Region from Potential Galactic PeVatron Candidates written by Sei Kato and published by Springer Nature. This book was released on with total page 180 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 Search for PeV Gamma Rays with the IceCube Observatory written by Zachary Dean Griffith and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last several decades, a wealth of observations of gamma-ray emission at TeV energies has increased our understanding of the extreme physical processes happening in our Galaxy. However, fundamental questions remain unanswered. To how high an energy are cosmic rays able to be accelerated in our galaxy, and how does that connect with the features observed in the cosmic-ray energy spectrum such as the "knee'', the "second knee'', and the "ankle''? Answers to these questions can be searched for by extending gamma-ray observations to higher energies. As the only experiment sensitive to PeV gamma rays in the Southern Hemisphere, the IceCube observatory can address these issues from a unique perspective. In this work, gamma-ray candidate events are selected from data observed by the surface and in-ice arrays of the IceCube observatory. This is accomplished by leveraging characteristic properties of gamma-ray induced air showers such as low muonic content and a deep shower maximum. Using five years of data, several searches for gamma-ray emission using unbinned likelihood methods are presented. The results of all searches are consistent with background, resulting in 90% flux upper limits that are the most stringent ever placed on PeV emission. The limits set on PeV gamma-ray point sources constrain, for the first time, the energy extension of a power-law flux for sources observed by HESS to have no break in their energy spectrum at TeV energies. Additionally, the resulting limit set by a search for an angular-integrated diffuse flux from the Galactic plane provides an upper bound useful for constructing Galactic cosmic-ray transport models
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 Transient Searches with the Hawc Gamma ray Observatory written by Alison Peisker and published by . This book was released on 2021 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: The universe contains many extremely energetic astrophysical sources that emit particles on timescales from fractions of a second to thousands of years. Studying these sources through gamma-ray and multi-messenger astronomy may help to reveal the answers to several remaining fundamental questions in physics. The High Altitude Water Cherenkov (HAWC) gamma-ray observatory, an extensive air shower array, is well-suited to perform transient searches due to its large field of view and high duty cycle. In this work, a catalog search of all very-high-energy gamma-ray sources in HAWC's field of view is conducted, revealing a total of 65 sources. Then a search for evaporating primordial black holes is performed. None are detected, so upper limits are set on their burst rate density. Finally, the IceCube neutrino observatory is introduced in order to perform a multi-messenger search for flaring gamma rays and neutrinos originating from the same point in the sky. None are detected, so upper limits are placed on the rate density and total energy of sources that produce both gamma rays and neutrinos. Performing these searches contributes to the understanding of the origins of cosmic rays and how astrophysical sources accelerate their particles to the high energies that are observed on Earth.
Download or read book The TeV gamma ray Emission of the Galactic Plane written by Armelle Jardin-Blicq and published by . This book was released on 2019* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unassociated Candidate TeV Sources from The HAWC Observatory written by Nicole Firestone and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As neutrally-charged astrophysical messengers, gamma rays serve as powerful tools for determining the origins of incredibly high-energy particles from across our universe [1]. Gamma rays are considered to have the highest energy of all electromagnetic radiation, with energies spanning from 0.5 MeV to about 100 TeV [2]. Although lower-energy gamma rays can originate from within our solar system, gamma rays in the GeV and TeV ranges tend to originate from sources beyond our solar system [1]. By investigating these sources, we can understand more about the astrophysical phenomena that characterize the most extreme conditions in our universe, such as supernova remnants, gamma-ray bursts, and pulsars [3]. The High Altitude Water Cherenkov Gamma-Ray Observatory (HAWC) is one of the most sensitive gamma-ray detectors in the very high energy (VHE) regime, with the capability to observe gamma rays from 100 GeV and 100 TeV [4]. In 2017, HAWC conducted a blind search encompassing two thirds of the sky and 508 days of observations [4]. In this search, there were 16 VHE gamma-ray excesses that were unassociated with any previously discovered gamma-ray sources [4]. Now with data from 1523 days of observations, we begin to study these 16 unassociated candidate TeV sources in more detail. In this work, we update the locations of maximum significance for these candidate TeV sources and analyze the temporal progression of their significance and flux. This allows us to determine if they have faded into the diffuse gamma radiation or if they can still be considered unassociated candidate TeV sources. We then reevaluate the morphologies and spectral energy distributions of the remaining sources and discuss any recent observations from other gamma-ray observatories. We find that 10 of these 16 unassociated candidate TeV sources can still be considered candidate sources. In the future, we plan to use data from other observatories to continue to put better constrains on the morphology and spectral energy distributions for these sources and better understand their acceleration mechanisms. In addition, we plan to conduct a similar investigation with new HAWC excesses discovered with recent data from 1523 days of observations [5]. By investigating these excesses in the high-energy gamma-ray sky, we can discover and characterize new extreme astrophysical phenomena and ultimately uncover valuable information about the physical mechanisms that accelerate particles to very high energies.
Download or read book A Search for Gamma Ray Emission from the Region of the Galactic Center written by Glen Hamilton Dahlbacka and published by . This book was released on 1972 with total page 288 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 Very High Energy Gamma Ray Astronomy written by T.C. Weekes and published by CRC Press. This book was released on 2003-04-08 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: High energy gamma-ray photons are the prime probes of the relativistic or high-energy universe, populated by black holes, neutron stars, supernovae, quasars, and matter-antimatter annihilations. Through studying the gamma-ray sky, astrophysicists are able to better understand the formation and behavior of these exotic and energetic bodies. V
Download or read book TeV Gamma Ray Astrophysics written by Heinrich J. Völk and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: The `International Heidelberg Workshop on TeV Gamma-Ray Astrophysics' brought together astrophysicists from the various fields which play a role in the formation of high energy gamma-ray emission. In particular, theoretical and observational aspects of the physics and astrophysics of pulsars and quasars, the acceleration of particles at Supernova Remnants and other strong astrophysical shock fronts, and cascade processes in universal background photon fields were comprehensively discussed in more than thirty reviews by leading experts. In their entirety these reviews describe the birth of a new field of astronomy. This field concerns cosmic gamma-rays of very high energy which are observed with ground-based optical telescopes due to the Cherenkov emission of the secondary particles created by the interaction of these gamma-rays with atoms in the Earth's atmosphere. Beyond that, the workshop encompassed the latest developments and trends in theory and observation of cosmic gamma-ray sources of all energies, from nuclear gamma-ray lines in the MeV-region, through the Bremsstrahlung, Inverse Compton, and pion decay continuum emission, to gamma-rays due the decay of exotic relics from the early Universe. Audience: Specialists as well as students in physics and astrophysics and young research workers.
Download or read book Cherenkov Reflections Gamma ray Imaging And The Evolution Of Tev Astronomy written by David Fegan and published by World Scientific. This book was released on 2019-06-27 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'This book is recommended to those interested in knowing how TeV astronomy began, evolved, and remains a growth area.The author has captured the difficulties of being a pioneer, amply demonstrating the need to keep the faith and work the problem until you succeed. Cherenkov telescopes are now in operation around the world, and at the dawn of the CTA era TeV astronomy has a lot of evolving still to do.'The ObservatoryThis book documents how TeV gamma-ray astronomy painstakingly emerged from 20th century traditional cosmic-ray physics to become a keystone feature of contemporary high-energy astrophysics, fundamental to our understanding of high-energy cosmic processes and interactions. Contemporary TeV observations are based on the Imaging Atmospheric Cherenkov Technique and in excess of two hundred individual galactic and extra-galactic gamma-ray sources have now been discovered and studied in detail.The book tells the story from the perspective of the Whipple Observatory collaboration, pioneers of the imaging technique. At the same time, parallel developments by the broader community are constantly referenced, discussed and evaluated, mainly in the TeV energy regime but also where relevant at PeV energies. The narrative traces the contributions of many important participants active in the field since the mid-1950s and critically evaluates and provides commentary on the progress of research until the first sources were established beyond doubt, during the late 1980s and early 1990s. The final chapter presents a short summary of the contemporary status of TeV gamma-ray astronomy.Written predominantly from a historical perspective, the author guides readers through many decades of instrumental development and evolution, using only minimal mathematical background. This book will appeal to astrophysicists, particle physicists, traditional optical and radio astronomers, as well as others working across a variety of related cognate disciplines. It should be of interest and value to graduate students involved with contemporary fourth-generation TeV research programs such as CTA (Cherenkov Telescope Array).
Download or read book Handbook of X ray and Gamma ray Astrophysics written by Cosimo Bambi and published by Springer Nature. This book was released on with total page 5912 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gamma ray Large Area Space Telescope written by and published by . This book was released on 1998 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science With The Cherenkov Telescope Array written by The Cta Consortium and published by World Scientific. This book was released on 2018-12-31 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the science to be carried out by the upcoming Cherenkov Telescope Array, a major ground-based gamma-ray observatory that will be constructed over the next six to eight years. The major scientific themes, as well as core program of key science projects, have been developed by the CTA Consortium, a collaboration of scientists from many institutions worldwide.CTA will be the major facility in high-energy and very high-energy photon astronomy over the next decade and beyond. CTA will have capabilities well beyond past and present observatories. Thus, CTA's science program is expected to be rich and broad and will complement other major multiwavelength and multimessenger facilities. This book is intended to be the primary resource for the science case for CTA and it thus will be of great interest to the broader physics and astronomy communities. The electronic version (e-book) is available in open access.
