English
Related papers

Related papers: Wavelet Analysis and Lognormal Distributions in GR…

200 papers

Cardiovascular system study using ECG signals have evolved tremendously in the domain of electronics and signal processing. However, there are certain floating challenges unresolved in the analysis and detection of abnormal performances of…

Computer Vision and Pattern Recognition · Computer Science 2014-08-05 T. R. Gopalakrishnan Nair , A. P. Geetha , M. Asharani

Traditionally gamma-ray bursts (GRBs) are classified in the $T_{90}$-hardness ratio two-dimensional plane into long/soft and short/hard GRBs. In this paper, we suggest to add the "amplitude" of GRB prompt emission as the third dimension as…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Hou-Jun Lü , Bing Zhang , En-Wei Liang , Bin-Bin Zhang , Takanori Sakamoto

We have developed an automatic search procedure to identify low-energy spectral features in GRBs. We have searched 133,000 spectra from 117 bright bursts and have identified 12 candidate features with significances ranging from our…

Astrophysics · Physics 2009-10-30 M. S. Briggs , D. L. Band , R. D. Preece , G. N. Pendleton , W. S. Paciesas , J. L. Matteson

We searched for anomalously long GRBs (GRBs) in the archival records of the Burst and Transient Sources Experiment (BATSE). Ten obvious superlong (>500 s) GRBs with almost continuous emission episodes were found. Nine of these events are…

Astrophysics · Physics 2015-06-24 Yana Tikhomirova , Boris E. Stern

Determining the kinds of gamma-ray bursts (GRBs) has been of interest to astronomers for many years. We analyzed 1599 GRBs from the Burst and Transient Source Experiment (BATSE) 4Br catalogue using $t$-mixtures-model-based clustering on all…

High Energy Astrophysical Phenomena · Physics 2018-09-28 Souradeep Chattopadhyay , Ranjan Maitra

Decades ago two classes of gamma-ray bursts were identified and delineated as having durations shorter and longer than about 2 s. Subsequently indications also supported the existence of a third class. Using maximum likelihood estimation we…

High Energy Astrophysical Phenomena · Physics 2016-04-27 I. Horvath , B. G. Toth

High-energy gamma-ray (>GeV) emission of gamma-ray bursts (GRBs) is very important in probing the jet evolution and particle acceleration of GRBs. The observations of high-energy photons are limited except for a few very bright GRBs,…

High Energy Astrophysical Phenomena · Physics 2026-03-11 Shi Chen , Qiang Yuan , Yi-Qing Guo , Ben-Zhong Dai , He Gao , Bing Zhang

We present the results of our study of the variability time scales of a sample of 27 long Swift Gamma-Ray Bursts (GRBs) with known redshifts. The variability time scale can help our understanding of fundamental GRB parameters such as the…

High Energy Astrophysical Phenomena · Physics 2009-06-18 T. N. Ukwatta , K. S. Dhuga , W. C. Parke , T. Sakamoto , C. B. Markwardt , S. D. Barthelmy , D. F. Cioffi , A. Eskandarian , N. Gehrels , L. Maximon , D. C. Morris

Observations of Gamma-Ray Bursts with the Fermi Large Area Telescope have prompted theoretical advances and posed big challenges in the understanding of such extreme sources, despite the fact that GRB emission above 100 MeV is a fairly rare…

High Energy Astrophysical Phenomena · Physics 2015-02-12 Giacomo Vianello , Nicola Omodei , Fermi/LAT collaboration

We present a homogeneous X-ray analysis of all 318 Gamma Ray Bursts detected by the X-ray Telescope on the Swift satellite up to 2008 July 23; this represents the largest sample of X-ray GRB data published to date. In Sections 2--3 we…

Clustering is an important tool to describe gamma-ray bursts (GRBs). We analyzed the Final BATSE Catalog using Gaussian-mixture-models-based clustering methods for six variables (durations, peak flux, total fluence and spectral hardness…

High Energy Astrophysical Phenomena · Physics 2019-06-05 B. G. Tóth , I. I. Rácz , I. Horváth

A sample of 427 gamma-ray bursts (GRBs), measured by the RHESSI satellite, is studied statistically with respect to duration and hardness ratio. Standard statistical tests are used, such as $\chi^2$, F-test and the maximum likelihood ratio…

High Energy Astrophysical Phenomena · Physics 2015-05-13 J. Řípa , A. Mészáros , C. Wigger , D. Huja , R. Hudec , W. Hajdas

Gamma-ray bursts (GRBs) are highly variable and exhibit strong spectral evolution. In particular, the emission properties vary from pulse to pulse in multipulse bursts. Here we present a time-resolved Bayesian spectral analysis of a…

High Energy Astrophysical Phenomena · Physics 2021-12-20 Liang Li , Felix Ryde , Asaf Pe'er , Hoi-Fung Yu , Zeynep Acuner

We present a new method of wavelet packet decomposition to be used in gravitational wave detection. An issue in wavelet analysis is what is the time-frequency resolution which is best suited to analyze data when in quest of a signal of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Riccardo Sturani , Roberto Terenzi

The evidence for spectral features in gamma-ray bursts is summarized. As a guide for evaluating the evidence, the properties of gamma-ray detectors and the methods of analyzing gamma-ray spectra are reviewed. In the 1980's, observations…

Astrophysics · Physics 2007-05-23 Michael S. Briggs

We use the BD2 sample of gamma-ray bursts (GRBs) based on 5.9 years of BATSE DISCLA data with a variety of models of the luminosity function to derive characteristic GRB luminosities, space densities and redshift distributions. Previously…

Astrophysics · Physics 2009-10-31 Maarten Schmidt

We demonstrate how the image analysis technique of wavelet decomposition can be applied to the gamma-ray sky to separate emission on different angular scales. New structures on scales that differ from the scales of the conventional…

High Energy Astrophysical Phenomena · Physics 2016-08-03 Samuel D. McDermott , Patrick J. Fox , Ilias Cholis , Samuel K. Lee

The distribution of the apparent total energy emitted by a gamma-ray burst reflects not only the distribution of the energy actually released by the burst engine, but also the distribution of beaming angles. Using the observed energy…

Astrophysics · Physics 2009-11-06 David L. Band

The High Altitude Water Cherenkov (HAWC) Gamma-ray Observatory is an extensive air shower detector operating in central Mexico, which has recently completed its first two years of full operations. If for a burst like GRB 130427A at a…

High Energy Astrophysical Phenomena · Physics 2017-08-07 The HAWC collaboration , R. Alfaro , C. Alvarez , J. D. Álvarez , R. Arceo , J. C. Arteaga-Velázquez , D. Avila Rojas , H. A. Ayala Solares , A. S. Barber , N. Bautista-Elivar , A. Becerril , E. Belmont-Moreno , S. Y. BenZvi , A. Bernal , J. Braun , C. Brisbois , K. S. Caballero-Mora , T. Capistrán , A. Carramiñana , S. Casanova , M. Castillo , U. Cotti , J. Cotzomi , S. Coutiño de León , E. de la Fuente , C. De León , T. DeYoung , R. Diaz Hernandez , B. L. Dingus , M. A. DuVernois , J. C. Díaz-Vélez , R. W. Ellsworth , K. Engel , D. W. Fiorino , N. Fraija , J. A. García-González , F. Garfias , M. Gerhardt , A. González Muñoz , M. M. González , J. A. Goodman , Z. Hampel-Arias , J. P. Harding , A. Hernandez-Almada , S. Hernandez , B. Hona , C. M. Hui , P. Hüntemeyer , A. Iriarte , A. Jardin-Blicq , V. Joshi , S. Kaufmann , D. Kieda , R. J. Lauer , W. H. Lee , D. Lennarz , H. León Vargas , J. T. Linnemann , A. L. Longinotti , G. Luis Raya , R. Luna-García , K. Malone , S. S. Marinelli , O. Martinez , I. Martinez-Castellanos , J. Martínez-Castro , H. Martínez-Huerta , J. A. Matthews , P. Miranda-Romagnoli , E. Moreno , M. Mostafá , L. Nellen , M. Newbold , R. Noriega-Papaqui , R. Pelayo , E. G. Pérez-Pérez , J. Pretz , Z. Ren , C. D. Rho , C. Rivière , D. Rosa-González , M. Rosenberg , E. Ruiz-Velasco , H. Salazar , F. Salesa Greus , A. Sandoval , M. Schneider , H. Schoorlemmer , G. Sinnis , A. J. Smith , R. W. Springer , P. Surajbali , I. Taboada , O. Tibolla , K. Tollefson , I. Torres , T. N. Ukwatta , G. Vianello , T. Weisgarber , S. Westerhoff , J. Wood , T. Yapici , P. W. Younk , A. Zepeda , H. Zhou

After seven years of science operation, the Fermi mission has brought great advances in the study of Gamma-ray Bursts (GRBs). Over 1600 GRBs have been detected by the Gamma-ray Burst Monitor, and more than 100 of these are also detected by…

High Energy Astrophysical Phenomena · Physics 2015-07-19 Elisabetta Bissaldi , Francesco Longo , Nicola Omodei , Giacomo Vianello , Andreas von Kienlin
‹ Prev 1 4 5 6 7 8 10 Next ›