Download or read book A Likelihood Search for Very High energy Gamma ray Bursts with the High Altitude Water Cherenkov Observatory written by Kathryne Woodle and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Gamma-Ray bursts (GRBs) are extremely powerful transient events that occur at cosmological distances. Observations of energy spectra of GRBs can provide information about the intervening space between the burst and Earth as well as about the source itself. GRBs have been observed up to nearly 100 GeV by satellite instruments; however, ground-based detectors are needed to provide enough exposure and statistics to determine the behavior of GRBs at those energies. The High Altitude Water Cherenkov Observatory (HAWC) is a second-generation extensive air shower detector that primarily observes very high-energy (VHE) photons, where VHE is defined as hundreds of GeV to hundreds of TeV. HAWC is built near the peak of Sierra Negra in Mexico at an altitude of 4100m. The high altitude allows the detector to observe air showers when more information is available for reconstruction. Due to its wide field of view (~2 sr) and high duty cycle (>90%), the HAWC observatory is sensitive to gamma rays in the sub-TeV to TeV energy range and can constrain the shape and cutoff of high-energy GRB spectra, especially in conjunction with observations from other detectors such as the Fermi LAT satellite. We present a likelihood-based search for VHE emission from the Fermi LAT GRBs that occurred in the field of view of HAWC during the last two years of its construction. Of the five bursts analyzed, no significant detections were observed; upper limits have been placed for each of the bursts. With less than 1/3 of the array active, the HAWC observatory limits for GRB 130702A, which is at a close redshift of z = 0.145, reach comparable sensitivity to lower energy instruments and are not limited by the EBL. With the array complete in March 2015, the sensitivity of HAWC is now greatly enhanced compared to the data analyzed in this dissertation. The future for a VHE GRB detetion by the HAWC observatory is bright.
Download or read book A Search for Very High Energy Photons from Gamma Ray Bursts with the High Altitude Water Cherenkov Observatory written by Matthew Rosenberg and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Gamma-Ray Bursts (GRBs) are brief, intense flashes of gamma rays lasting from a fraction of a second to minutes. The prompt emission from these explosive events outshines all the stars in their entire host galaxy. Thought to be produced by the core collapse of massive stars and the merger of compact stellar remnants in distant galaxies, GRBs can liberate on the order of 10^54 ergs of gravitational potential energy in just milliseconds. In addition to constituting an interesting phenomenon in their own right, these cosmic engines accelerate particles to energy scales unattainable in laboratories on Earth and thus provide a potentially interesting probe of fundamental physics as well as source candidates for ultra-high energy cosmic rays. We present recent efforts to extend the observation of GRBs beyond ~100 GeV with the High Altitude Water Cherenkov (HAWC) observatory. Located in Puebla, Mexico at a latitude of 19 degrees north and an altitude of 4100 meters above sea level, HAWC employs a 20,000 square meter array of 300 water Cherenkov detectors to observe the relativistic charged particles produced in the extensive air showers that develop upon the collision of high-energy gamma rays with Earths atmosphere. This technique provides sensitivity to ~100 GeV 100 TeV gamma rays, allows for nearly continuous operations, and achieves a wide instantaneous field of view of ~2 sr that allows for daily monitoring of the northern sky. HAWC is thus ideally suited to capture any emission above ~100 GeV from transient events like GRBs. As GRB photons above a few TeV in energy are likely to be absorbed by the extra-galactic background light before reaching Earth, HAWCs ~100 GeV 1 TeV data is of prime importance in the search for high-energy GRB emission. However, the small air-shower data necessary to achieve this lower threshold of ~100 GeV has previously been poorly modeled in HAWC simulations and has therefore not been used in past HAWC GRB searches. We will show that these modeling discrepancies were caused by an inaccurate treatment of detector noise, outline a solution that allows HAWC to achieve its lowest possible energy threshold, and present a method to reduce the impact of detector noise on HAWCs angular resolution in this newly recovered small air-shower data. Along with new GRB search algorithms, these improvements provide up to an order of magnitude improvement in HAWCs sensitivity to gamma-ray bursts. We use these new techniques to scan archival HAWC data for gamma-ray emission coincident with GRBs detected by the Fermi and Swift satellites between December 2014 and April 2018. While no significant detections were found, a comparison of our upper limits on the flux above 100 GeV from GRBs 170206A and 171120A with Fermi measurements suggests a cut-off or spectral steepening below that energy under a redshift assumption of z less than ~0.3. However, these limits are not sufficiently strict to compellingly constrain GRB models with predictions for TeV scale gamma-ray emission.
Download or read book Search for Higher energy Radiation from Gamma ray Bursts written by Richard Schnee and published by . This book was released on 1996 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Search for Quantum Gravity written by Sabine Hossenfelder and published by Springer. This book was released on 2017-11-15 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes recent developments in the research area of quantum gravity phenomenology. A series of short and nontechnical essays lays out the prospects of various experimental possibilities and their current status. Finding observational evidence for the quantization of space-time was long thought impossible. In the last decade however, new experimental design and technological advances have changed the research landscape and opened new perspectives on quantum gravity. Formerly dominated by purely theoretical constructions, quantum gravity now has a lively phenomenology to offer. From high precision measurements using macroscopic quantum oscillators to new analysis methods of the cosmic microwave background, no stone is being left unturned in the experimental search for quantum gravity. This book sheds new light on the connection of astroparticle physics with the quantum gravity problem. Gravitational waves and their detection are covered. It illustrates findings from the interconnection between general relativity, black holes and Planck stars. Finally, the return on investment in quantum-gravitation research is illuminated. The book is intended for graduate students and researchers entering the field.
Download or read book A Search for Supersymmetric Q balls with the High Altitude Water Cherenkov Observatory written by Peter Karn and published by . This book was released on 2014 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The High Altitude Water Cherenkov (HAWC) Observatory is a gamma-ray experiment currently under construction at Sierra Negra in Mexico. When complete it will consist of a 22,000 square meter array of 300 water Cherenkov detectors. Although HAWC is designed to study gamma rays from galactic and extra-galactic sources, the large volume of instrumented water (each tank holds ∼188,000 liters) gives the opportunity to search for rare objects. One such target is the Q-ball, a very massive, subrelativistic particle that can have a large baryon number and can be stable since their creation in the early universe. If stable, Q-balls would make up some of the dark matter of the universe, but their large mass means their flux is very low. HAWC has a flexible data acquisition system which, with a dedicated trigger algorithm for non-relativistic species, allows a search for Q-balls traversing the detector. Using a 174.5 days of live time and a portion of the planned array, a search was performed with negative results. The obtained upper limits are competitive with previously published limits on Q-balls, and HAWC will be able to set a better limit than any other when it is complete.
Download or read book A Search for Very High Energy Gamma Ray Emission from Cygnus X 3 written by Andrew Harold Szentgyorgyi and published by . This book was released on 1986 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gamma ray Bursts written by Cheng Ho and published by Cambridge University Press. This book was released on 1992-03-12 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizes the current understanding of Astronomical gamma-ray bursts, short-lived flashes of high-energy radiation, which have eluded even a basic explanation for over twenty years, and describes directions for future research.
Download or read book A Search for Short Duration Very High Energy Emission from Gamma ray Bursts written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for High energy Emission from Gamma ray Bursts with a Large Water Cerenkov Detector written by Tom Yang and published by . This book was released on 1998 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for Bursts of Very High Energy Gamma Rays with Milagro written by Vlasios Vasileiou and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 2005 with total page 512 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.
Download or read book Solar Stellar and Galactic Connections between Particle Physics and Astrophysics written by Alberto Carramiñana and published by Springer Science & Business Media. This book was released on 2007-03-23 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book collects extended and specialized reviews on topics linking astrophysics and particle physics at a level between a graduate student and a young researcher. The book also includes three reviews on observational techniques used in forefront astrophysics and short articles on research performed in Latin America. The reviews, updated and written by specialized researchers, describe the state of the art in the related research topics.
Download or read book Search for a High energy gamma ray Burst by an Airborne Experiment written by R. Enomoto and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutrino Astronomy Current Status Future Prospects written by Thomas K Gaisser and published by World Scientific. This book was released on 2017-03-20 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: This review volume is motivated by the recent discovery of high-energy astrophysical neutrinos by IceCube. The aim of the book is to bring together chapters on the status of current and future neutrino observatories with chapters on the implications and possible interpretations of the present observations and their upper limits. Each chapter is a mini-review of one aspect of the subject by leading experts. Taken together, the chapters constitute an up-to-date review of high-energy astrophysical neutrinos and their potential sources.
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 A Study of Transient Very high energy Gamma ray Emission from Gamma ray Bursts and Supernovae with H E S S written by Dirk Lennarz and published by . This book was released on 2012 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
