Utilizing Swift-XRT Data to Identify Source Classes in Fermi Unassociated Objects PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Utilizing Swift-XRT Data to Identify Source Classes in Fermi Unassociated Objects PDF full book. Access full book title Utilizing Swift-XRT Data to Identify Source Classes in Fermi Unassociated Objects by Matthew Pryal. Download full books in PDF and EPUB format.
Author: Matthew Pryal Publisher: ISBN: Category : Languages : en Pages :
Book Description
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.
Author: Matthew Pryal Publisher: ISBN: Category : Languages : en Pages :
Book Description
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.
Author: Stephen Kerby Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
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.
Author: The Cta Consortium Publisher: World Scientific ISBN: 9813270101 Category : Science Languages : en Pages : 365
Book Description
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.
Author: Felix Aharonian Publisher: Springer Science & Business Media ISBN: 364236134X Category : Science Languages : en Pages : 369
Book Description
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.
Author: Thomas K Gaisser Publisher: World Scientific ISBN: 9814759422 Category : Science Languages : en Pages : 251
Book Description
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.
Author: Nanda Rea Publisher: Springer Science & Business Media ISBN: 3642172512 Category : Science Languages : en Pages : 656
Book Description
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.
Author: Matthew Pryal
Author: Matthew Pryal
Author: Stephen Kerby
Author: The Cta Consortium
Author: Patrick L. Shopbell
Author: R. J. Hanisch
Author: Felix Aharonian
Author: James Kendall Hosmer
Author: D. R. Lorimer
Author: Thomas K Gaisser
Author: Nanda Rea