J/ApJ/844/126 New spectral lag measurements of 50 Fermi/GBM GRBs (Shao+, 2017)
A new measurement of the spectral lag of gamma-ray bursts and its implications
for spectral evolution behaviors.
Shao L., Zhang B.-B., Wang F.-R., Wu X.-F., Cheng Y.-H., Zhang Xi, Yu B.-Y.,
Xi B.-J., Wang X., Feng H.-X., Zhang M., Xu D.
<Astrophys. J., 844, 126 (2017)>
=2017ApJ...844..126S 2017ApJ...844..126S
ADC_Keywords: GRB
Keywords: gamma-ray burst: general; methods: data analysis;
radiation mechanisms: nonthermal
Abstract:
We carry out a systematical study of the spectral lag properties of 50
single-pulsed gamma-ray bursts (GRBs) detected by the Fermi Gamma-Ray
Burst Monitor. By dividing the light curves into multiple consecutive
energy channels, we provide a new measurement of the spectral lag that
is independent of energy channel selections. We perform a detailed
statistical study of our new measurements. We find two similar
power-law energy dependencies of both the pulse arrival time and pulse
width. Our new results on the power-law indices would favor the
relativistic geometric effects for the origin of spectral lag.
However, a complete theoretical framework that can fully account for
the diverse energy dependencies of both arrival time and pulse width
revealed in this work is still lacking. We also study the spectral
evolution behaviors of the GRB pulses. We find that a GRB pulse with
negligible spectral lag would usually have a shorter pulse duration
and would appear to have a "hardness-intensity tracking" behavior, and
a GRB pulse with a significant spectral lag would usually have a
longer pulse duration and would appear to have a "hard-to-soft"
behavior.
Description:
This work made extensive use of the data from the Gamma-Ray Burst
Monitor (GBM) on board the Fermi Gamma-ray Space Telescope. For the
first step, we searched in the official GBM online burst catalog
(Gruber+ 2014ApJS..211...12G 2014ApJS..211...12G ; von Kienlin+ 2014, J/ApJS/211/13) for
bright bursts with a total fluence F>5x10-6erg/cm-2 in 10-1000keV.
See section 2 for the details on the sample selection.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 139 50 Our sample of 50 GRBs detected by GBM and results
on the spectral lag
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See also:
J/ApJ/609/935 : Gamma-ray burst formation rate (Yonetoku+, 2004)
J/A+A/525/A53 : GBM parameters for detected FERMI bursts (Guetta+, 2011)
J/ApJ/740/104 : BATSE GRB pulse catalog - preliminary data (Hakkila+, 2011)
J/ApJS/199/18 : The Fermi GBM catalog (Paciesas+, 2012)
J/ApJ/754/121 : GRBs from Fermi/GBM and LAT (The Fermi Team, 2012)
J/ApJ/756/112 : Fermi/GBM GRB time-resolved spectral analysis (Lu+, 2012)
J/ApJ/763/15 : Fermi GRB analysis. III. T90 distributions (Qin+, 2013)
J/ApJS/207/39 : IPN supplement to the Fermi GBM (Hurley+, 2013)
J/A+A/564/A125 : AGN Torus model comparison of AGN in the CDFS (Buchner+, 2014)
J/ApJS/211/13 : The second Fermi/GBM GRB catalog (4yr) (von Kienlin+, 2014)
J/ApJS/216/32 : Localizations of GRBs with Fermi GBM (Connaughton+, 2015)
J/ApJS/218/11 : The 5yr Fermi/GBM magnetar burst catalog (Collazzi+, 2015)
J/ApJ/811/93 : Fermi/GBM GRB minimum timescales (Golkhou+, 2015)
J/A+A/573/A81 : Spectral properties of energetic GRBs (Yu+, 2015)
J/A+A/588/A135 : Fermi/GBM GRB time-resolved spectral catalog (Yu+, 2016)
J/ApJ/818/110 : Short GRBs with Fermi GBM and Swift BAT (Burns+, 2016)
J/ApJS/223/28 : The third Fermi/GBM GRB catalog (6yr) (Bhat+, 2016)
J/ApJS/229/31 : IPN supplement to the 2nd Fermi GBM catalog (Hurley+, 2017)
http://fermi.gsfc.nasa.gov/ssc/ : Fermi Science Support Center home page
http://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html : Fermi GBM burst
online catalog
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 I09 --- Fermi Burst identifier (Trigger ID: YYMMDDNNN) (1)
11- 16 F6.2 s T90 [1.4/140] 90% duration of the burst
18- 21 F4.2 s e_T90 [0.09/7] Uncertainty in T90 (2)
23- 26 F4.2 s Bin [0.05/3] Manually determined time bin size
28- 34 F7.3 s t0 [-20/35] Earliest arrival time of the most
energetic photons
36- 40 F5.3 s e_t0 [0.01/9] Lower uncertainty in t0 (2)
42- 47 F6.3 s E_t0 [0.03/14] Upper uncertainty in t0 (2)
49- 54 F6.3 s tau [0.9/98] Limiting spectral lag at 1keV
56- 61 F6.3 s e_tau [0.01/47] Lower uncertainty in tau (2)
63- 68 F6.3 s E_tau [0.03/65] Upper uncertainty in tau (2)
70- 74 F5.3 --- Beta [0.02/0.9] Power law index, Β
76- 80 F5.3 --- e_Beta [0.002/0.4] Lower uncertainty in Beta (2)
82- 86 F5.3 --- E_Beta [0/3.5] Upper uncertainty in Beta (2)
88- 93 F6.3 s omega [0.5/50] Limiting half pulse width at 1keV
95- 99 F5.3 s e_omega [0.05/6] Lower uncertainty in omega (2)
101-105 F5.3 s E_omega [0.07/7] Upper uncertainty in omega (2)
107-111 F5.3 --- gamma [0.01/0.7] Power law index, γ
113-117 F5.3 --- e_gamma [0.01/0.05] Lower uncertainty in gamma (2)
119-123 F5.3 --- E_gamma [0.01/0.08] Upper uncertainty in gamma (2)
125-126 A2 --- NaI NaI detector (3)
128-133 F6.3 s dt-HR [0.1/12] Hardness-intensity time delay
135-139 F5.3 s e_dt-HR [0.009/5] Uncertainty in dt-HR
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Note (1): Data provided by the official GBM online burst catalogs:
Gruber+ (2014ApJS..211...12G 2014ApJS..211...12G); von Kienlin+ (2014, J/ApJS/211/13 ;
<Fermi bnYYMMDDNN> in Simbad).
Note (2): All of the errors in this work indicate a confidence interval
of 1σ uncertainty.
Note (3): Only the data from the brightest NaI detector are used for analysis
in this work.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Mar-2018