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Download or read book Fermi LAT Search for Dark Matter in Gamma-Ray Lines and the Inclusive Photon Spectrum written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Andrea Marie Albert
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (858 download)
Download or read book Search for Gamma-ray Spectral Lines with the Fermi Large Area Telescope and Dark Matter Implications written by Andrea Marie Albert and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Measurements indicate that ~85% of the matter in the universe neither emits nor reflects light--appropriately called "dark matter". We believe dark matter may be primary composed of new particles, but we know very little about their nature. What dark matter is and how it interacts is one of the top cosmological mysteries today. Detecting a signal from particle dark matter would not only offer insight into the fundamental nature of dark matter, but it would also be strong evidence for physics existing beyond the Standard Model. A promising dark matter candidate is a weakly interacting massive particle (WIMP). Measurements indicate that the Milky Way Galaxy resides in a halo of dark matter, making it an ideal laboratory for investigating these elusive particles. As WIMPs are predicted to be heavy, their interactions should produce high-energy gamma rays that would be detected by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope (Fermi). If WIMPs annihilate directly into gamma rays, the gamma-ray energy would be the same as the rest mass energy of the WIMPs, which is currently unknown. This process would cause a "pile-up" of gamma rays at a specific energy, producing a sharp line (or bump) in the otherwise relatively smooth gamma-ray energy spectrum. This distinctive signal would not only be strong evidence for the existence of WIMPs, but would also provide information about their mass. We have searched for spectral lines in the energy range 5 to 300 GeV using 3.7 years of Fermi LAT data, reprocessed with updated calorimeter calibration constants, and an improved energy dispersion model from previous LAT Collaboration line searches. We search in five regions selected to optimize sensitivity to different theoretically-motivated density distributions of WIMPs. We do not find any globally significant lines in our a priori search regions and present 95% confidence limits for annihilation cross section and decay lifetimes. We extensively discuss potential systematic effects in the search. Finally, we consider claims of evidence for a spectral line at 130 GeV, compare our results to previous work, and discuss why this search finds a somewhat lower statistical significance for a potential line than other works.
Author : Wang Ping
Publisher : Stanford University
ISBN 13 :
Total Pages : 167 pages
Book Rating : 4.F/5 ( download)
Download or read book The Search for WIMP Dark Matter Continuum Gamma-ray Emission from Dark Matter Satellites in the Milky Way Using the Fermi LAT written by Wang Ping and published by Stanford University. This book was released on 2011 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on the search for unknown dark matter (DM) satellites in the Milky Way using the Fermi Large Area Space Telescope (LAT). The Fermi Gamma-ray Space Telescope (Fermi) is a next generation space observatory, which was successfully launched on June 11th, 2008. The LAT is the principal scientific instrument onboard. Its unprecedented angular resolution and sensitivity in the 100 MeV to > 300 GeV energy range makes it an excellent instrument for probing the sky for DM satellites. Current N-body simulations based on the Lambda-CDM cosmology model predict a large number of as yet unobserved DM satellites in our galaxy; some satellites are predicted to be extended sources (> 1deg extension) as seen by the LAT. Our work assumes that a significant component of DM is a Weakly Interacting Massive Particle (WIMP) in the 100 GeV mass range. The annihilation of WIMPs results in many high energy gamma rays that can be well measured by the LAT. The WIMP produced gamma-ray spectrum from the putative DM satellites is considerably harder than most astrophysical sources. Also, DM satellites have no astronomical counterparts in the X-ray and radio bands, and the emission has no time variability. My thesis will focus on a blind analysis in the search for unknown DM satellites using one year of LAT data, and setting constraints on some WIMP models based on the results of our analysis in which we find no candidates.
Author :
Publisher :
ISBN 13 :
Total Pages : 6 pages
Book Rating : 4.:/5 (893 download)
Download or read book Fermi LAT Search for Photon Lines from 30 to 200 GeV. written by and published by . This book was released on 2010 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dark matter (DM) particle annihilation or decay can produce monochromatic [gamma]-rays readily distinguishable from astrophysical sources. [gamma]-ray line limits from 30 GeV to 200 GeV obtained from 11 months of Fermi Large Area Space Telescope data from 20-300 GeV are presented using a selection based on requirements for a [gamma]-ray line analysis, and integrated over most of the sky. We obtain [gamma]-ray line flux upper limits in the range 0.6-4.5 x 10−9 cm−2s−1, and give corresponding DM annihilation cross-section and decay lifetime limits. Theoretical implications are briefly discussed.
Author :
Publisher :
ISBN 13 :
Total Pages : 4 pages
Book Rating : 4.:/5 (727 download)
Download or read book Detecting Dark Matter Annihilation Lines with Fermi written by and published by . This book was released on 2009 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dark matter constitutes one of the most intriguing but so far unresolved issues in physics today. In many extensions of the Standard Model the existence of a stable Weakly Interacting Massive Particle (WIMP) is predicted. The WIMP is an excellent dark matter particle candidate and one of the most interesting scenarios include an annihilation of two WIMPs into two gamma-rays. If the WIMPs are assumed to be non-relativistic, the resulting photons will both have an energy equal to the mass of the WIMP and manifest themselves as a monochromatic spectral line in the energy spectrum. This type of signal would represent a 'smoking gun' for dark matter, since no other known astrophysical process should be able to produce it. In these proceedings we give an overview of the different approaches to a search for dark matter lines that the Fermi-LAT collaboration is pursuing and the various challenges involved.
Author :
Publisher :
ISBN 13 :
Total Pages : 7 pages
Book Rating : 4.:/5 (925 download)
Download or read book Indirect Searches for Dark Matter with the Fermi Large Area Telescope written by and published by . This book was released on 2015 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce [gamma] rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for [gamma]-ray spectral lines and [gamma]-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.
Author : Tanushree Basak
Publisher : Morgan & Claypool Publishers
ISBN 13 : 1643271326
Total Pages : 63 pages
Book Rating : 4.6/5 (432 download)
Download or read book An Approach to Dark Matter Modelling written by Tanushree Basak and published by Morgan & Claypool Publishers. This book was released on 2018-09-05 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the field of particle and astrophysics, one of the major unresolved problems is to understand the nature and properties of dark matter, which constitutes almost 80% of the matter content of the universe. This book gives a pedagogical introduction to the field of dark matter in general, and in particular to the model building perspective. Starting from the evidence and need for dark matter, it goes into the deeper understanding of how to accommodate a dark matter candidate in a particle physics model. This book focuses on teaching the basic tools for model building of dark matter, starting from the easiest to gradually the difficult one. Although there are plenty of dark matter models available in the literature, this book concentrates on the important ones. This book aims to motivate the reader to propose a new dark matter model complying with all observational constraints.
Author : Gilles Vertongen
Publisher :
ISBN 13 :
Total Pages : 31 pages
Book Rating : 4.:/5 (837 download)
Download or read book Hunting Dark Matter Gamma-ray Lines with the Fermi LAT written by Gilles Vertongen and published by . This book was released on 2011 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Gilles Vertongen
Publisher :
ISBN 13 :
Total Pages : 28 pages
Book Rating : 4.:/5 (724 download)
Download or read book Hunting 1-500 GeV Dark Matter Gamma-ray Lines with the Fermi LAT written by Gilles Vertongen and published by . This book was released on 2010 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Wang Ping
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (722 download)
Download or read book The Search for WIMP Dark Matter Continuum Gamma-ray Emission from Dark Matter Satellites in the Milky Way Using the Fermi LAT written by Wang Ping and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on the search for unknown dark matter (DM) satellites in the Milky Way using the Fermi Large Area Space Telescope (LAT). The Fermi Gamma-ray Space Telescope (Fermi) is a next generation space observatory, which was successfully launched on June 11th, 2008. The LAT is the principal scientific instrument onboard. Its unprecedented angular resolution and sensitivity in the 100 MeV to> 300 GeV energy range makes it an excellent instrument for probing the sky for DM satellites. Current N-body simulations based on the Lambda-CDM cosmology model predict a large number of as yet unobserved DM satellites in our galaxy; some satellites are predicted to be extended sources (> 1deg extension) as seen by the LAT. Our work assumes that a significant component of DM is a Weakly Interacting Massive Particle (WIMP) in the 100 GeV mass range. The annihilation of WIMPs results in many high energy gamma rays that can be well measured by the LAT. The WIMP produced gamma-ray spectrum from the putative DM satellites is considerably harder than most astrophysical sources. Also, DM satellites have no astronomical counterparts in the X-ray and radio bands, and the emission has no time variability. My thesis will focus on a blind analysis in the search for unknown DM satellites using one year of LAT data, and setting constraints on some WIMP models based on the results of our analysis in which we find no candidates.
Download or read book The Search for Dark Matter with the Fermi Gamma Ray Space Telescope written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fermi Gamma-Ray Space Telescope has been scanning the gamma ray sky since it was launched by NASA in June 2008 and has a mission lifetime goal of 10 years. Largely due to our particle physics heritage, one of the main physics topics being studied by the Fermi LAT Collaboration is the search for dark matter via indirect detection. My talk will review the progress of these studies, something on how the LAT detector enables them, and expectations for the future. I will discuss both gamma-ray and (electron + positron) searches for dark matter, and some resulting theoretical implications.
Author : Roman Pasechnik
Publisher : Frontiers Media SA
ISBN 13 : 2889639908
Total Pages : 180 pages
Book Rating : 4.8/5 (896 download)
Download or read book Phenomena Beyond the Standard Model: What Do We Expect for New Physics to Look Like? written by Roman Pasechnik and published by Frontiers Media SA. This book was released on 2020-09-03 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
Author : Yvonne Vasetta Edmonds
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (745 download)
Download or read book A Search for Spectral Lines from WIMP Annihilation in the Milky Way Using the Fermi Large Area Telescope written by Yvonne Vasetta Edmonds and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The most popular class of dark matter candidates is the class of weakly-interacting massive particles (WIMPs). The Fermi Large Area Telescope has the possibility of indirectly detecting WIMPs by the flux from their annihilation/decay products. When a WIMP annihilates or decays directly into a photon gamma and another particle Y the photons are monochromatic. Detection of the resulting spectral line(s) would provide convincing evidence for particulate dark matter and could provide the WIMP mass. In the case of no detection, knowledge of the dark matter distribution can be used to place limits on the annihilation cross section and lifetime for the WIMP(s) to Y-gamma channel. We present the spectrum from 4.8 to 264 GeV and spectral line flux upper limits, obtained from a subset of this spectrum, from 7 to 200 GeV. The spatial region of the dataset covers a large portion of the sky, the high latitudes plus the Galactic Center. We report upper limits on the WIMP cross sections for annihilation to gamma-gamma and Z-gamma and lower limits on the WIMP lifetime for decay to gamma-neutrino. We discuss the implications of the spectrum and line flux limits for several dark matter models with optimistic branching ratios for photon channels.
Author : The Cta Consortium
Publisher : World Scientific
ISBN 13 : 9813270101
Total Pages : 365 pages
Book Rating : 4.8/5 (132 download)
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.
Author : Gianfranco Bertone
Publisher : Cambridge University Press
ISBN 13 : 0521763681
Total Pages : 763 pages
Book Rating : 4.5/5 (217 download)
Download or read book Particle Dark Matter written by Gianfranco Bertone and published by Cambridge University Press. This book was released on 2010-01-07 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the dark matter problem in particle physics, astrophysics and cosmology for graduate students and researchers.
Author :
Publisher :
ISBN 13 :
Total Pages : 8 pages
Book Rating : 4.:/5 (94 download)
Download or read book Dark Matter Searches with the Fermi-LAT in the Direction of Dwarf Spheroidals written by and published by . This book was released on 2015 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :
Publisher :
ISBN 13 :
Total Pages : 47 pages
Book Rating : 4.:/5 (925 download)
Download or read book Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background written by and published by . This book was released on 2015 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ~ 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. As a result, we quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals.
