Download or read book Utilizing Swift XRT Data to Identify Source Classes in Fermi Unassociated Objects written by Matthew Pryal and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Large Area Telescope on board the Fermi Gamma-Ray Space Telescope has revolutionized the detection and identification of gamma-ray emitting astrophysical objects since the launch of Fermi in 2008. Gamma-rays are the highest energy photons observed in the universe and our understanding of objects that emit gamma-rays is essential to our understanding of physics at its greatest limits. The 1FGL, 2FGL, and 3FGL Fermi catalogs outline the identification of over 2000 gamma-ray emitting objects such as blazars and pulsars, but there still remains many unassociated objects in the Fermi catalogs. In this thesis we attempt to statistically show associations of these Fermi unassociated objects in the 1FGL and 2FGL catalogs by utilizing data mining and machine learning techniques to find distinct separations in the properties of known blazars and pulsars. Our analysis is unique in that we will be utilizing known X-ray fluxes for the unassociated objects observed by the Swift X-ray Telescope in addition to the gamma-ray properties available in the Fermi catalogs. Our analysis shows distinct separations in the gamma-ray properties of known blazars and pulsars when compared to X-ray flux and we were able to suggest possible associations to 136 previously unassociated Fermi objects.
Download or read book Multiwavelength Analysis and Classification of Fermi Gamma ray Sources written by Stephen Kerby and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most recent catalogue of Fermi-LAT gamma-ray point sources includes over 4000 associated sources, most of which are pulsars or blazars. However, over 2000 sources are "unassociated", defying confident classification or identification based on gamma-ray data alone. Our understanding of the high-energy sky is systematically incomplete while these unassociated sources remain unexamined. An ongoing search for low-energy counterparts using the Neil Gehrels Swift Observatory has identified over three hundred X-ray/UV/optical counterparts to Fermi unassociated sources and placed limits on the maximum X-ray flux for almost a thousand more; these discoveries facilitate spatial localization and broadband SED analysis of the unassociated sources. Analyzing Swift-XRT and -UVOT data for these counterparts, we conduct machine learning classification to identify likely blazars and pulsars from this sample. Between random forest, neural network, and support vector machine classifiers, we find that the unassociated sources with low-energy counterparts are mostly dimmer blazars while also discovering several unusual sources and new gamma-ray pulsars. Using Fermi, Swift, and archival IR and radio data, we create a sample of 106 new blazars; via another machine learning program, we show that these dimmer blazars tend to have higher synchrotron peak frequencies like BL Lac objects. These findings align with the predictions of the blazar sequence, extending and confirming that observational framework with a totally new sample. While the dim blazars in our new sample confirm the predictions of the blazar sequence, many of the unassociated targets without Swift-XRT detections may be even dimmer blazars, especially those at high galactic latitude. Furthermore, several sources are not well-explained by either pulsar or blazar models, or are coincident with stars or known galactic binaries. In-depth examination of these unique objects shows that - like the associated sources - the unassociated sources contain rare minority classes ranging from low-mass X-ray binaries and cataclysmic variables to extreme Seyfert galaxies and star-forming regions.
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 Astronomical Data Analysis Software and Systems XIV written by Patrick L. Shopbell and published by . This book was released on 2005 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astronomical Data Analysis Software and Systems II written by R. J. Hanisch and published by . This book was released on 1993 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysics at Very High Energies written by Felix Aharonian and published by Springer Science & Business Media. This book was released on 2013-04-04 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the success of Cherenkov Astronomy and more recently with the launch of NASA’s Fermi mission, very-high-energy astrophysics has undergone a revolution in the last years. This book provides three comprehensive and up-to-date reviews of the recent advances in gamma-ray astrophysics and of multi-messenger astronomy. Felix Aharonian and Charles Dermer address our current knowledge on the sources of GeV and TeV photons, gleaned from the precise measurements made by the new instrumentation. Lars Bergström presents the challenges and prospects of astro-particle physics with a particular emphasis on the detection of dark matter candidates. The topics covered by the 40th Saas-Fee Course present the capabilities of current instrumentation and the physics at play in sources of very-high-energy radiation to students and researchers alike. This book will encourage and prepare readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors.
Download or read book The Story of the Jews written by James Kendall Hosmer and published by . This book was released on 1885 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Pulsar Astronomy written by D. R. Lorimer and published by Cambridge University Press. This book was released on 2005 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 2004 book provides a concise description of pulsar research, presenting key techniques, background information and results.
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 High Energy Emission from Pulsars and their Systems written by Nanda Rea and published by Springer Science & Business Media. This book was released on 2011-02-04 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the inaugural meeting of the Sant Cugat Forum on Astrophysics was to address, in a global context, the current understanding of and challenges in high-energy emissions from isolated and non-isolated neutron stars, and to confront the theoretical picture with observations of both the Fermi satellite and the currently operating ground-based Cherenkov telescopes. Participants have also discussed the prospects for possible observations with planned instruments across the multi-wavelength spectrum (e.g. SKA, LOFAR, E-VLT, IXO, CTA) and how they will impact our theoretical understanding of these systems. In keeping with the goals of the Forum, this book not only represents the proceedings of the meeting, but also a reflection on the state-of-the-art in the topic.
Download or read book Timing Neutron Stars written by H. Ögelman and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea for organizing an Advanced Study Institute devoted largely to neutron star timing arose independently in three places, at Istanbul, Garching and Amster dam; when we became aware of each other's ideas we decided to join forces. The choice of a place for the Institute, in Turkey, appealed much to us all, and it was then quickly decided that Qe§me would be an excellent spot. When the preparations for the Institute started, early in 1987, we could not have guessed how timely the subject actually was. Of course, the recently dis covered QPO phenomena in accreting neutron stars and half a dozen binary and millisecond radio pulsars known at the time formed one of the basic motivations for organizing this Institute. But none of us could have guessed that later in 1987 we were to witness the wonderful discovery of the binary and millisecond radio pulsars in globular clusters and, -as if Nature wished to give us a special present for this the discovery in March 1988 of a millisecond pulsar in an eclipsing binary Institu- system, the first eclipsing radio pulsar ever found, and the second fastest in the sky! The discussion of this pulsar, its formation and fate was one of the highlights of this meeting, especially since its discoverers were among the participants of the Institute and could provide us with first-hand information.
Download or read book Neutron Stars and Pulsars IAU S291 written by Joeri van Leeuwen and published by Cambridge University Press. This book was released on 2013-04-25 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: IAU Symposium 291 features a rich harvest of recent scientific discoveries and looks forward to the many exciting avenues for future neutron-star research. The volume starts with general, lively, comprehensive introductions to three main themes that successfully communicate the excitement of current pulsar research. The subsequent reviews and contributions on hot topics cover: ongoing searches for pulsars, both radio and gamma-ray; neutron star formation and properties; binary pulsars; pulsar timing and tests of gravitational theories; magnetars; radio transients; radio, X-ray and gamma-ray pulse properties and emission mechanisms; and future facilities. This range of topics clearly illustrates the diverse nature and wide application of neutron-star research. Through a combination of introductory reviews and practically complete coverage of current results from across the electromagnetic spectrum, IAU S291 is the perfect reference for neutron-star researchers and also provides an excellent read for advanced undergraduate and starting graduate students.
Download or read book Galactic Astronomy written by James Binney and published by Princeton University Press. This book was released on 2021-07-13 with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the definitive treatment of the phenomenology of galaxies--a clear and comprehensive volume that takes full account of the extraordinary recent advances in the field. The book supersedes the classic text Galactic Astronomy that James Binney wrote with Dimitri Mihalas, and complements Galactic Dynamics by Binney and Scott Tremaine. It will be invaluable to researchers and is accessible to any student who has a background in undergraduate physics. The book draws on observations both of our own galaxy, the Milky Way, and of external galaxies. The two sources are complementary, since the former tends to be highly detailed but difficult to interpret, while the latter is typically poorer in quality but conceptually simpler to understand. Binney and Merrifield introduce all astronomical concepts necessary to understand the properties of galaxies, including coordinate systems, magnitudes and colors, the phenomenology of stars, the theory of stellar and chemical evolution, and the measurement of astronomical distances. The book's core covers the phenomenology of external galaxies, star clusters in the Milky Way, the interstellar media of external galaxies, gas in the Milky Way, the structure and kinematics of the stellar components of the Milky Way, and the kinematics of external galaxies. Throughout, the book emphasizes the observational basis for current understanding of galactic astronomy, with references to the original literature. Offering both new information and a comprehensive view of its subject, it will be an indispensable source for professionals, as well as for graduate students and advanced undergraduates.
Download or read book Astrophysics Of Gas Nebulae and Active Galactic Nuclei written by Donald E. Osterbrock and published by University Science Books. This book was released on 2006 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thoroughly revised and expanded throughout, the new edition is a graduate-level text and reference book on gaseous nebulae, nova and supernova remnants. Much of the new data and new images are from the Hubble Space Telescope with two wholly new chapters being added along with other new features. The previous edition which was tried and tested for thirty years has now been succeeded by a revised, updated, larger edition, which will be valuable to anyone seriously interested in astrophysics.
Download or read book The Physics of Gamma Ray Bursts written by Bing Zhang and published by Cambridge University Press. This book was released on 2019 with total page 617 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete text on the physics of gamma-ray bursts, the most brilliant explosions since the Big Bang.
Download or read book Cosmic Rays at Earth written by P.K.F. Grieder and published by Elsevier. This book was released on 2001-07-27 with total page 1117 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1912 Victor Franz Hess made the revolutionary discovery that ionizing radiation is incident upon the Earth from outer space. He showed with ground-based and balloon-borne detectors that the intensity of the radiation did not change significantly between day and night. Consequently, the sun could not be regarded as the sources of this radiation and the question of its origin remained unanswered. Today, almost one hundred years later the question of the origin of the cosmic radiation still remains a mystery.Hess' discovery has given an enormous impetus to large areas of science, in particular to physics, and has played a major role in the formation of our current understanding of universal evolution. For example, the development of new fields of research such as elementary particle physics, modern astrophysics and cosmology are direct consequences of this discovery. Over the years the field of cosmic ray research has evolved in various directions: Firstly, the field of particle physics that was initiated by the discovery of many so-called elementary particles in the cosmic radiation. There is a strong trend from the accelerator physics community to reenter the field of cosmic ray physics, now under the name of astroparticle physics. Secondly, an important branch of cosmic ray physics that has rapidly evolved in conjunction with space exploration concerns the low energy portion of the cosmic ray spectrum. Thirdly, the branch of research that is concerned with the origin, acceleration and propagation of the cosmic radiation represents a great challenge for astrophysics, astronomy and cosmology. Presently very popular fields of research have rapidly evolved, such as high-energy gamma ray and neutrino astronomy. In addition, high-energy neutrino astronomy may soon initiate as a likely spin-off neutrino tomography of the Earth and thus open a unique new branch of geophysical research of the interior of the Earth. Finally, of considerable interest are the biological and medical aspects of the cosmic radiation because of it ionizing character and the inevitable irradiation to which we are exposed. This book is a reference manual for researchers and students of cosmic ray physics and associated fields and phenomena. It is not intended to be a tutorial. However, the book contains an adequate amount of background materials that its content should be useful to a broad community of scientists and professionals. The present book contains chiefly a data collection in compact form that covers the cosmic radiation in the vicinity of the Earth, in the Earth's atmosphere, at sea level and underground. Included are predominantly experimental but also theoretical data. In addition the book contains related data, definitions and important relations. The aim of this book is to offer the reader in a single volume a readily available comprehensive set of data that will save him the need of frequent time consuming literature searches.
Download or read book Wavelet Methods for Time Series Analysis written by Donald B. Percival and published by Cambridge University Press. This book was released on 2006-02-27 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: This introduction to wavelet analysis 'from the ground level and up', and to wavelet-based statistical analysis of time series focuses on practical discrete time techniques, with detailed descriptions of the theory and algorithms needed to understand and implement the discrete wavelet transforms. Numerous examples illustrate the techniques on actual time series. The many embedded exercises - with complete solutions provided in the Appendix - allow readers to use the book for self-guided study. Additional exercises can be used in a classroom setting. A Web site offers access to the time series and wavelets used in the book, as well as information on accessing software in S-Plus and other languages. Students and researchers wishing to use wavelet methods to analyze time series will find this book essential.
