J/other/RAA/21.254 GRB isotropic energy function (Liu+, 2021)
The isotropic energy function and formation rate of short gamma-ray bursts.
Liu Z.-Y., Zhang F.-W., Zhu S.-Y.
<Res. Astron. Astrophys., 21, 254 (2021)>
=2021RAA....21..254L 2021RAA....21..254L (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays ; GRB
Keywords: gamma-ray bursts: general - methods: data analysis
Abstract:
Gamma-ray bursts (GRBs) are brief, intense, gamma-ray flashes in the
universe, lasting from a few milliseconds to a few thousand seconds.
For short gamma-ray bursts (sGRBs) with duration less than 2 seconds,
the isotropic energy (Eiso) function may be more scientifically
meaningful and accurately measured than the luminosity (Lp) function.
In this work we construct, for the first time, the isotropic energy
function of sGRBs and estimate their formation rate. First, we derive
the Lp-Ep correlation using 22 sGRBs with known redshifts and
well-measured spectra and estimate the pseduo redshifts of 334 Fermi
sGRBs. Then, we adopt the Lynden-Bell c- method to study isotropic
energy functions and formation rate of sGRBs without any assumption. A
strong evolution of isotropic energy Eiso∝(1+z)5.79 is
found, which is comparable to that between Lp and z. After removing
effect of the cosmic evolution, the isotropic energy function can be
reasonably fitted by a broken power law, which is
φ(Eiso,0)∝E_iso,0-0.45 for dim sGRBs and
φ(Eiso,0)∝E_iso,0-1.11 for bright sGRBs, with the
break energy 4.92x1049erg. We obtain the local formation rate of
sGRBs is about 17.43 events/Gpc3/yr. If assuming a beaming angle is
6° to 26°, the local formation rate including off-axis sGRBs
is estimated as ρ0,all= 155.79-3202.35events/Gpc3/yr.
Description:
We concentrate our analysis on the sGRBs detected only by the Fermi
detector to minimize the influence of different instruments (with
different sensitivities and energy bands). The Fermi GRBs are selected
from the Fermi catalog
(https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html) until
the end of January 2020, in total, there are 2698 events.
We use o sample of 334 sGRBs
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 121 333 Fermi sGRB Sample
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See also:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html : Fermi catalog
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- GRB GRB name (GRBYYMMDDNNN)
14- 19 F6.4 --- z Redshift
21- 24 F4.2 s T90 Observed frame duration
26- 29 F4.2 s e_T90 Observed frame duration error
31- 37 F7.2 keV Epeak Observed peak energy
39- 45 F7.2 keV e_Epeak Observed peak energy error
47- 51 F5.2 -- alpha Low energy spectral index
53- 56 F4.2 -- e_alpha Low energy spectral index error
58- 63 F6.2 10-13J/cm2 Sgamma Fluence (in 10-6erg/cm2)
65- 68 F4.2 10-13J/cm2 e_Sgamma Fluence (in 10-6erg/cm2)
70- 74 F5.2 10-9W/m2 Fpeak Peak flux (in 10-6erg/cm2/s)
76- 79 F4.2 10-9W/m2 e_Fpeak Peak flux error (in 10-6erg/cm2/s)
81- 90 F10.5 10+43J Eiso Isotropic energy (in 1050erg)
92- 99 F8.5 10+43J e_Eiso Isotropic energy error (in 1050erg)
102-111 F10.5 10+44W Lpeak Peak luminosity (in 1051erg/s)
113-121 F9.5 10+44W e_Lpeak Peak luminosity error (in 1051erg/s)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 17-Feb-2022