J/ApJ/820/66 Cosmic evolution of long gamma-ray burst luminosity (Deng+, 2016) ================================================================================ Cosmic evolution of long gamma-ray burst luminosity. Deng C.-M., Wang X.-G., Guo B.-B., Lu R.-J., Wang Y.-Z., Wei J.-J., Wu X.-F., Liang E.-W. =2016ApJ...820...66D (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: GRB ; Redshifts ; Spectroscopy Keywords: gamma-ray burst: general - methods: statistical - stars: formation Abstract: The cosmic evolution of gamma-ray burst (GRB) luminosity is essential for revealing the GRB physics and for using GRBs as cosmological probes. We investigate the luminosity evolution of long GRBs with a large sample of 258 Swift/BAT GRBs. By describing the peak luminosity evolution of individual GRBs as L_p_{prop.to}(1+z)^k^, we get k=1.49+/-0.19 using the nonparametric {tau} statistics method without considering observational biases of GRB trigger and redshift measurement. By modeling these biases with the observed peak flux and characterizing the peak luminosity function of long GRBs as a smoothly broken power law with a break that evolves as L_b_{prop.to}(1+z)^kb^, we obtain k_b_=1.14^+0.99^_-0.47_ through simulations based on the assumption that the long GRB rate follows the star formation rate incorporating the cosmic metallicity history. The derived k and k_b_ values are systematically smaller than those reported in previous papers. By removing the observational biases of the GRB trigger and redshift measurement based on our simulation analysis, we generate mock complete samples of 258 and 1000 GRBs to examine how these biases affect the {tau} statistics method. We get k=0.94+/-0.14 and k=0.80+/-0.09 for the two samples, indicating that these observational biases may lead to overestimating the k value. With the large uncertainty of k_b_ derived from our simulation analysis, one cannot even convincingly argue for a robust evolution feature of the GRB luminosity. Description: Our sample includes only the redshift-known long GRBs observed with Swift/BAT from 2005 January to 2015 April. Low-luminosity GRBs are excluded since they may belong to another distinct population (e.g., Chapman et al. 2007MNRAS.382L..21C; Liang et al. 2007ApJ...662.1111L; Lu et al. 2010ApJ...725.1965L). Although the durations of some GRBs, such as GRB 050724 and GRB 060614, are larger than 2s, we do not include them in our sample since they may be from merger of compact stars (Berger et al. 2005Natur.438..988B; Gehrels et al. 2006Natur.444.1044G; Zhang et al. 2007ApJ...655L..25Z, 2009ApJ...703.1696Z). The afterglow and host galaxy observations of the high-z SGRB GRB 090426 (T_90_=1.2s) show that it may be from the collapse of a massive star (Antonelli et al. 2009A&A...507L..45A; Xin et al. 2011MNRAS.410...27X). We thus include this GRB in our sample. We finally obtain a sample of 258 GRBs. They are reported in Table 1. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 48 258 The Data of Our GRB Sample -------------------------------------------------------------------------------- See also: J/ApJS/175/179 : The BAT1 gamma-ray burst catalog (Sakamoto+, 2008) J/ApJ/711/495 : Durations of Swift/BAT GRBs (Butler+, 2010) J/ApJ/731/103 : Redshift catalog for Swift long GRBs (Xiao+, 2011) J/ApJS/195/2 : The second Swift BAT GRB catalog (BAT2) (Sakamoto+, 2011) (Lien+, 2016) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 7 A7 --- GRB GRB name (YYMMDDA) 9- 15 F7.5 --- z Redshift (1) 17- 21 F5.2 [10-7W] log10Lp The 1s peak isotropic luminosity in the 15-150keV band, log_10_L_p_ (in erg/s) 23- 26 F4.2 [10-7W] e_log10Lp Uncertainty in log10Lp 28- 33 F6.2 ph/cm2/s P The 1s peak photon flux in the 15-150keV band (in photons/cm^2^/s) (1) 35- 38 F4.2 ph/cm2/s e_P Uncertainty in P (1) 40- 43 F4.2 --- Gamma Photon index {Gamma} (1) (2) 45- 48 F4.2 --- e_Gamma Uncertainty in Gamma (1) -------------------------------------------------------------------------------- Note (1): Data taken from the NASA Web site (http://swift.gsfc.nasa.gov/). Note (2): All of the 1s peak spectra of bursts are fitted to a simple power law, giving a photon index {Gamma}. -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Tiphaine Pouvreau [CDS] 06-Feb-2018