scholarly journals BATSE Observations of the Large-Scale Isotropy of Gamma-Ray Bursts

1996 ◽  
Vol 459 ◽  
pp. 40 ◽  
Author(s):  
Michael S. Briggs ◽  
William S. Paciesas ◽  
Geoffrey N. Pendleton ◽  
Charles A. Meegan ◽  
Gerald J. Fishman ◽  
...  
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
Gamma Ray Bursts

scholarly journals The Galaxy Hosts And Large-Scale Environments of Short-Hard Gamma-Ray Bursts

2005 ◽  
Author(s):  
Jason X. Prochaska ◽  
J.S. Bloom ◽  
H.-W. Chen ◽  
R.J. Foley ◽  
D.A. Perley ◽  
...  
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
The Galaxy

scholarly journals The Galaxy Hosts and Large‐Scale Environments of Short‐Hard Gamma‐Ray Bursts

2006 ◽  
Vol 642 (2) ◽  
pp. 989-994 ◽  
Author(s):  
J. X. Prochaska ◽  
J. S. Bloom ◽  
H.‐W. Chen ◽  
R. J. Foley ◽  
D. A. Perley ◽  
...  
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
The Galaxy

scholarly journals Spatial Distribution of the Gamma-ray Bursts and the Cosmological Principle

2016 ◽  
Vol 12 (S324) ◽  
pp. 89-90
Author(s):  
Attila Mészáros
Keyword(s):  
Spatial Distribution ◽  
Angular Distribution ◽  
Large Scale ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Cosmological Principle ◽  
The Universe

AbstractThe Cosmological Principle claims that in the large scale average the visible parts of the universe are isotropic and homogeneous. In year 1998 the author, together with his two colleagues, discovered that the BATSE’s short gamma-ray bursts are not distributed isotropically on the sky. This first discovery was followed by other ones confirming both the existence of anisotropies in the angular distribution of bursts and the existence of huge Gpc structures in the spatial distribution. All this means that these anisotropies should reject the Cosmological Principle, because the large scale averaging hardly can be provided. This was claimed in year 2009. The aim of this contribution is to survey these publications since 1998 till today.

scholarly journals Anomalies in the GRBs' distribution

2015 ◽  
Vol 11 (S319) ◽  
pp. 2-2
Author(s):  
Zsolt Bagoly ◽  
István Horváth ◽  
Jon Hakkila ◽  
L. Viktor Tóth
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Host Galaxies ◽  
Isotropic Distribution ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Luminous Objects ◽  
Current Sample ◽  
Different Levels

AbstractGamma-ray bursts are the most luminous objects known: they outshine their host galaxies making them ideal candidates for probing large-scale structure. Earlier it has been found that the angular distribution of different groups of GRBs (long, intermediate and short) show deviation from the full randomness at different levels (e.g. Vavrek et al. (2008)).In the current sample there are more than 361 GRBs with position and redshift: the large scale homogeneous and isotropic distribution were checked with nearest-neighbour tests and with the two-point correlation function.

scholarly journals The synchrotron polarization in decaying magnetic field in gamma-ray bursts

2020 ◽  
Vol 498 (3) ◽  
pp. 3492-3502
Author(s):  
K F Cheng ◽  
X H Zhao ◽  
J M Bai
Keyword(s):  
Magnetic Field ◽  
Energy Band ◽  
Large Scale ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Polarization Degree ◽  
Band Spectrum ◽  
Polarization Angle ◽  
Radiation Mechanism

ABSTRACT Polarization can serve as a probe of the radiation mechanism and magnetic field (MF) configuration in gamma-ray bursts (GRBs). In the case of constant MF, the synchrotron polarization in the prompt phase of GRBs has been widely studied. In this paper, we consider the case of the decaying MF. We calculate the time-averaged and instantaneous synchrotron polarizations in a pulse for different viewing angles and for the large-scale decaying MF model, which can explain the so-called Band spectrum. We find that the on-axis time-averaged polarization degree (PD) in the energy band of 50–500 keV for the decaying large-scale MF model (∼0.6 for typical parameters) is higher than that in the constant MF model (∼0.5). An interesting result is the instantaneous PD in the off-axis case will experience a turnover, i.e. the PD will evolve from a positive value to a negative one. This suggests the polarization angle (PA) change by an angle of 90°. Such a result is roughly consistent with the discovery of the PA evolution within a pulse in some bursts, such as GRB 170114A and GRB 160821A. Our result implies at least a part of bursts (off-axis bursts) should have the PA evolution in a pulse.

scholarly journals Revisiting the statistical isotropy of GRB sky distribution

2019 ◽  
Vol 490 (4) ◽  
pp. 4481-4488 ◽  
Author(s):  
Uendert Andrade ◽  
Carlos A P Bengaly ◽  
Jailson S Alcaniz ◽  
Salvatore Capozziello
Keyword(s):  
Correlation Function ◽  
Angular Correlation ◽  
Large Scale ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Significant Evidence ◽  
Standard Cosmology ◽  
Angular Correlation Function ◽  
Statistical Isotropy

ABSTRACT The assumption of homogeneity and isotropy on large scales is one of the main hypotheses of the standard cosmology. In this paper, we test the hypothesis of isotropy from the two-point angular correlation function of 2626 gamma-ray bursts (GRB) of the FERMI GRB catalogue. We show that the uncertainties in the GRB positions induce spurious anisotropic signals in their sky distribution. However, when such uncertainties are taken into account no significant evidence against the large-scale statistical isotropy is found. This result remains valid even for the sky distribution of short-lived GRB, contrarily to previous reports.

scholarly journals On the Large‐Scale Angular Distribution of Short Gamma‐Ray Bursts

2008 ◽  
Vol 673 (2) ◽  
pp. 968-971 ◽  
Author(s):  
A. Bernui ◽  
I. S. Ferreira ◽  
C. A. Wuensche
Keyword(s):  
Angular Distribution ◽  
Large Scale ◽  
Gamma Ray ◽  
Gamma Ray Bursts
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