English
Related papers

Related papers: A Cautionary Note on Gamma Ray Burst Nearest Neigh…

200 papers

We use Bayesian methods to analyze the distribution of gamma ray burst intensities reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts, presuming the distribution of burst sources (``bursters'') is isotropic. We study both…

Astrophysics · Physics 2009-10-30 Thomas J. Loredo , Ira M. Wasserman

Several pairs of observable properties of Gamma Ray Bursts (GRBs) are known to be correlated. Many such correlations are straightforward predictions of the 'cannonball' model of GRBs. We extend our previous discussions of the subject to a…

Astrophysics · Physics 2010-11-05 Shlomo Dado , Arnon Dar , A. De Rujula

A possible subclass of gamma-ray bursts -- those with few, wide pulses, spectral lags of order one to several seconds, and soft spectra -- has been identified. Their Log[N]-Log[Fp] distribution approximates a -3/2 power-law, suggesting…

Astrophysics · Physics 2009-11-10 Jay P. Norris

The prompt emission mechanism of gamma-ray bursts (GRB) even after several decades remains a mystery. However, it is believed that correlations between observable GRB properties given their huge luminosity/radiated energy and redshift…

High Energy Astrophysical Phenomena · Physics 2018-04-25 Maria Dainotti

It is usual, in gamma-ray burst (GRB) studies, to compare the average properties of bright and faint GRBs, with the assumption that brightness classes reflect distance classes. When brightness is intented to reflect the distance to the…

Astrophysics · Physics 2008-02-03 J-L. Atteia

We present a catalog of the probabilistic redshift estimates and for 1366 individual Long-duration Gamma-Ray Bursts (LGRBs) detected by the Burst And Transient Source Experiment (BATSE). This result is based on a careful selection and…

High Energy Astrophysical Phenomena · Physics 2020-11-04 Joshua A. Osborne , Amir Shahmoradi , Robert J. Nemiroff

It is often stated that gamma-ray bursts (GRBs) have typical energies of several hundreds $\keV$, where the typical energy may be characterized by the hardness H, the photon energy corresponding to the peak of $\nu F_{\nu}$. Among the 54…

Astrophysics · Physics 2009-10-30 Ehud Cohen , Tsvi Piran , Ramesh Narayan

Milagrito, a detector sensitive to gamma-rays at TeV energies, monitored the northern sky during the period February 1997 through May 1998. With a large field of view and high duty cycle, this instrument was used to perform a search for TeV…

Gamma-Ray Bursts (GRBs) are very energetic cosmological transients. Long GRBs are usually associated with Type Ib/c Supernovae (SNe), and we refer to them as GRB-SNe. Since the associated SN for a given GRB is observed only at low redshift,…

High Energy Astrophysical Phenomena · Physics 2022-10-13 M. G. Dainotti , B. De Simone , M. I. Khadir , K. Kawaguchi , T. J. Moriya , T. Takiwaki , N. Tominaga , A. Gangopadhyay

In this paper, we propose an ensemble learning algorithm called \textit{under-bagging $k$-nearest neighbors} (\textit{under-bagging $k$-NN}) for imbalanced classification problems. On the theoretical side, by developing a new learning…

Machine Learning · Statistics 2021-09-03 Hanyuan Hang , Yuchao Cai , Hanfang Yang , Zhouchen Lin

Gamma-ray bursts (GRBs) are commonly attributed to the demise of massive stars or the merger of binary compact objects. However, their varied emission characteristics strongly imply the existence of multiple GRB classes based on progenitor…

High Energy Astrophysical Phenomena · Physics 2024-07-12 Nishil Mehta , Shabnam Iyyani

The multi-messenger observation of gamma-ray burst (GRB)\,170817A from the nearby binary neutron-star merger GW170817 demonstrated that low-energy $\gamma$-ray emission can be observed at relatively large angles from GRB jet axes. If such…

High Energy Astrophysical Phenomena · Physics 2019-03-20 Imre Bartos , Kyung-hwan Lee , Alessandra Corsi , Zsuzsa Marka , Szabolcs Marka

Fast Radio Bursts (FRBs) are highly energetic millisecond-duration astrophysical phenomena typically categorized as repeaters or non-repeaters. However, observational limitations may result in misclassifications, potentially leading to a…

High Energy Astrophysical Phenomena · Physics 2025-04-16 Da-Chun Qiang , Jie Zheng , Zhi-Qiang You , Sheng Yang

Correlation analysis of Swift gamma-ray burst coordinates and nearby star locations (catalog Gliese) reveals 4 coincidences with good angular accuracy. The random probability is 4\times 10^{-5}, so evidencing that coincident stars are…

High Energy Astrophysical Phenomena · Physics 2011-04-19 B. I. Luchkov

We discuss the preliminary results of spectral analysis simulations involving anticipated correlated multi-wavelength observations of gamma-ray bursts (GRBs) using Swift's Burst Alert Telescope (BAT) and the Gamma-Ray Large Area Space…

Astrophysics · Physics 2009-11-13 Michael Stamatikos , Takanori Sakamoto , David L. Band

Gamma-Ray Bursts (GRBs) have been conventionally bifurcated into two distinct categories dubbed "short" and "long", depending on whether their durations are less than or greater than two seconds respectively. However, many authors have…

High Energy Astrophysical Phenomena · Physics 2017-03-01 Soham Kulkarni , Shantanu Desai

The Fermi Gamma-ray Burst Monitor (GBM) has detected over 1400 Gamma-Ray Bursts (GRBs) since it began science operations in July, 2008. We use a subset of over 300 GRBs localized by instruments such as Swift, the Fermi Large Area Telescope,…

The luminosity distance describing the effect of local inhomogeneities in the propagation of light proposed by Zeldovich-Kantowski-Dyer-Roeder (ZKDR) is tested with two probes for two distinct ranges of redshifts: supernovae Ia (SNe Ia) in…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-03 Nora Bretón , Ariadna Montiel

K-Nearest Neighbours (k-NN) is a popular classification and regression algorithm, yet one of its main limitations is the difficulty in choosing the number of neighbours. We present a Bayesian algorithm to compute the posterior probability…

Machine Learning · Computer Science 2017-06-05 Giuseppe Nuti

We measure the local rates of ``low-luminosity'' (LL-GRBs, i.e. L<10^{48--49}erg/sec) and ``high-luminosity'' Gamma-ray Bursts (HL-GRBs). The values are in the range n0=100--1800 Gpc^(-3)yr^(-1) and n0=100--550 Gpc^(-3) yr^(-1),…

Astrophysics · Physics 2009-01-19 Dafne Guetta , Massimo Della Valle
‹ Prev 1 4 5 6 7 8 10 Next ›