scholarly journals Gamma-ray burst afterglow plateau break time–luminosity correlations favour thick shell models over thin shell models

2014 ◽  
Vol 445 (3) ◽  
pp. 2414-2423 ◽  
Author(s):  
Hendrik J. van Eerten
2013 ◽  
Vol 437 (3) ◽  
pp. 2448-2460 ◽  
Author(s):  
K. Leventis ◽  
R. A. M. J. Wijers ◽  
A. J. van der Horst

Author(s):  
A Budai ◽  
P Raffai ◽  
B Borgulya ◽  
B A Dawes ◽  
G Szeifert ◽  
...  

Abstract We propose a method to detect possible non-stationarities of gamma-ray burst jets. Assuming that the dominant source of variability in the prompt gamma light curve is the non-stationarity of the jet, we show that there should be a connection between the variability measure and the characteristic angle of the jet derived from the jet break time of the afterglow. We carried out Monte Carlo simulations of long gamma-ray burst observations assuming three radial luminosity density profiles for jets and randomizing all burst parameters, and created samples of gamma light curves by simulating jets undergoing Brownian motions with linear restoring forces. We were able to demonstrate that the connection between the variability and the characteristic angle is an anti-correlation in case of uniform and power-law jet profiles, and a correlation in case of a Gaussian profile. We have found that as low as 50 (144) gamma-ray burst observations with jet angle measurements can be sufficient for a 3σ (5σ) detection of the connection. The number of observations required for the detection depends on the underlying jet beam profile, ranging from 50 (144) to 237 (659) for the four specific profile models we tested.


New Astronomy ◽  
2010 ◽  
Vol 15 (8) ◽  
pp. 749-754 ◽  
Author(s):  
Alexander Tchekhovskoy ◽  
Ramesh Narayan ◽  
Jonathan C. McKinney

2012 ◽  
Vol 8 (S292) ◽  
pp. 190-190
Author(s):  
J. M. Chen ◽  
L. W. Jia ◽  
E. W. Liang

AbstractGRBs are the most luminous events in the Universe. They are detectable from local to high-z universe and may serve as probes for high-z galaxies (e.g., Savaglio et al. 2009; Kewley & Dopita 2002). We compile the observations for 61 GRB host galaxies from literature. Their redshifts range from 0.0085 to 6.295. We present the statistical properties of the GRB host galaxies, including the stellar mass (M*), star-forming rate (SFR), metallicity (Z), extinction (AV), and neutral hydrogen column density (NH). We explore possible correlations among the properties of gamma-ray burst host galaxies and their cosmic evolution with observations of 61 GRB host galaxies. Our results are shown in Figure 1. A clear Z-M* relation is found in our sample, which is Z ~ M0.4. The host galaxies of local GRBs with detection of accompanied supernovae also share the same relation with high-z GRB host galaxies. A trend that a more massive host galaxy tends to have a higher star-formation rate is found. The best linear fit gives a tentative relation, i.e, SFR ~ M0.75. No any correlation is found between AV and NH. A GRB host galaxy at a higher redshift also tends to have a higher SFR. Even in the same redshift, the SFR may vary over three orders of magnitude. The metallicity of the GRB host galaxies is statistically higher than that of the QSO DLAs. The full version of our results please refer to Chen et al. (2012).


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