scholarly journals Formation Rate, Evolving Luminosity Function, Jet Structure, and Progenitors for Long Gamma‐Ray Bursts

2004 ◽  
Vol 611 (2) ◽  
pp. 1033-1040 ◽  
Author(s):  
Claudio Firmani ◽  
Vladimir Avila‐Reese ◽  
Gabriele Ghisellini ◽  
Alexander V. Tutukov
Keyword(s):  
Luminosity Function ◽  
Gamma Ray ◽  
Formation Rate ◽  
Gamma Ray Bursts ◽  
Jet Structure

scholarly journals The luminosity function and formation rate of a complete sample of long gamma-ray bursts

2019 ◽  
Vol 488 (4) ◽  
pp. 4607-4613 ◽  
Author(s):  
Guang-Xuan Lan ◽  
Hou-Dun Zeng ◽  
Jun-Jie Wei ◽  
Xue-Feng Wu
Keyword(s):  
Luminosity Function ◽  
Gamma Ray ◽  
Formation Rate ◽  
Gamma Ray Bursts ◽  
Likelihood Method ◽  
Complete Sample ◽  
Empirical Density ◽  
Power Law Function ◽  
Current Sample ◽  
First Time

ABSTRACT We study the luminosity function and formation rate of long gamma-ray bursts (GRBs) by using a maximum likelihood method. This is the first time this method is applied to a well-defined sample of GRBs that is complete in redshift. The sample is composed of 99 bursts detected by the Swift satellite, 81 of them with measured redshift and luminosity for a completeness level of $82\, {\rm per\, cent}$. We confirm that a strong redshift evolution in luminosity (with an evolution index of $\delta =2.22^{+0.32}_{-0.31}$) or in density ($\delta =1.92^{+0.20}_{-0.21}$) is needed in order to reproduce the observations well. But since the predicted redshift and luminosity distributions in the two scenarios are very similar, it is difficult to distinguish between these two kinds of evolutions only on the basis of the current sample. Furthermore, we also consider an empirical density case in which the GRB rate density is directly described as a broken power-law function and the luminosity function is taken to be non-evolving. In this case, we find that the GRB formation rate rises like $(1+z)^{3.85^{+0.48}_{-0.45}}$ for $z\lesssim 2$ and is proportional to $(1+z)^{-1.07^{+0.98}_{-1.12}}$ for $z\gtrsim 2$. The local GRB rate is $1.49^{+0.63}_{-0.64}$ Gpc−3 yr−1. The GRB rate may be consistent with the cosmic star formation rate (SFR) at $z\lesssim 2$, but shows an enhancement compared to the SFR at $z\gtrsim 2$.

scholarly journals The Luminosity Function of Long Gamma-Ray Burst and their rate at z ≥ 6

2008 ◽  
Vol 4 (S255) ◽  
pp. 212-216
Author(s):  
R. Salvaterra ◽  
S. Campana ◽  
G. Chincarini ◽  
T. R. Choudhury ◽  
S. Covino ◽  
...  
Keyword(s):  
Star Formation ◽  
Luminosity Function ◽  
Gamma Ray ◽  
Formation Rate ◽  
Gamma Ray Bursts ◽  
Test Model ◽  
The Past ◽  
Model Predictions ◽  
Low Metallicity ◽  
Luminosity Evolution

AbstractWe compute the luminosity function (LF) and the formation rate of long gamma ray bursts (GRBs) in three different scenarios: i) GRBs follow the cosmic star formation and their LF is constant in time; ii) GRBs follow the cosmic star formation but the LF varies with redshift; iii) GRBs form preferentially in low–metallicity environments. We then test model predictions against the Swift 3-year data, showing that scenario i) is robustly ruled out. Moreover, we show that the number of bright GRBs detected by Swift suggests that GRBs should have experienced some sort of luminosity evolution with redshift, being more luminous in the past. Finally we propose to use the observations of the afterglow spectrum of GRBs at z ≥ 5.5 to constrain the reionization history, and then applied our method to the case of GRB 050904.

The X-ray luminosity function of short gamma-ray bursts

2021 ◽  
Vol 366 (4) ◽  
Author(s):  
Zhi-Ying Liu ◽  
Fu-Wen Zhang ◽  
Si-Yuan Zhu
Keyword(s):  
Luminosity Function ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
X Ray

scholarly journals The luminosity function of Swift long gamma-ray bursts

2011 ◽  
Vol 416 (3) ◽  
pp. 2174-2181 ◽  
Author(s):  
Xiao-Feng Cao ◽  
Yun-Wei Yu ◽  
K. S. Cheng ◽  
Xiao-Ping Zheng
Keyword(s):  
Luminosity Function ◽  
Gamma Ray ◽  
Gamma Ray Bursts
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