Analysis for Ground-detected GRB170710B
Analysis Summary
Notes:
- 1) No attempt has been made to eliminate the non-significant decimal places.
- 2) This is a special analysis for ground-detected GRB. The event data duration is likely to be shorter than the burst duration. In such cases, the burst durations are found using the quad-rate data, and spectral analyses are only available for event data range.
- 3) When spectral analysis covers slew times, the analysis uses an average response file made by some sub-response-files with a 5-s time interval during slew times.
==========================================================================
BAT GROUND-DETECTED GRB DATA PROCESSING REPORT
(This burst occurred during telescope slew)
Process Script Ver: batgrbproduct v2.46
Process Start Time: Mon Jul 10 17:01:54 EDT 2017
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/GRB170710B
======================================================================
Trigger: 00086619 Segment: 001
BAT Trigger Time: 521367025.6
UTC: 20170710T08:10:06.251 [includes UTCF correction]
Where From?: Ground analysis (best_duration.txt)
NOTE: BAT trigger time for ground-detected burst during slew is the T100 start time.
Analysis Position: [ source = GCN ]
RA: 43.12361967 Dec: 42.68415110 [deg; J2000]
Refined Position: [ source = BAT mosaic image ]
RA: 43.1220545845827 Dec: 42.6787730091842 [deg; J2000]
{ 02h 52m 29.3s , +42d 40' 43.6" }
+/- 0.810837503439 [arcmin] (estimated 90% radius based on SNR)
SNR: 41.0458949592
Angular difference between the GCN position (ra=43.12361967, dec=42.68415110 deg) and this refined position is 0.330 arcmin
Partial Coding Fraction: Unavailable because the burst occurred during slew.
Duration
T90: 54.4000000357628 +/- 1.6
Measured from: 1.6
to: 56 [s; relative to TRIGTIME]
T50: 30.4000000357628 +/- 1.6
Measured from: 12.8
to: 43.2 [s; relative to TRIGTIME]
=== Fluence/Peak Flux Summary ===
Model Band1 Band2 Band3 Band4 Band5 Total
15-25 25-50 50-100 100-350 15-150 15-350 keV
Fluence Power-law 2.79e-07 5.52e-07 8.52e-07 2.87e-06 2.38e-06 4.55e-06 erg/cm2
Error 2.26e-08 2.60e-08 4.35e-08 3.35e-07 1.07e-07 3.60e-07 erg/cm2
Peak flux Power-law 2.43e-01 3.42e-01 3.56e-01 6.82e-01 1.16e+00 1.62e+00 ph/cm2/s
Error 6.98e-02 6.17e-02 5.14e-02 2.04e-01 1.68e-01 2.43e-01 ph/cm2/s
Fluence Cutoff-PL 2.76e-07 5.55e-07 8.52e-07 2.65e-06 2.37e-06 4.34e-06 erg/cm2
Error 2.51e-08 2.76e-08 4.65e-08 6.01e-07 1.13e-07 6.15e-07 erg/cm2
Peak flux Cutoff-PL 1.52e-01 3.55e-01 4.22e-01 2.37e-01 1.09e+00 1.17e+00 ph/cm2/s
Error 8.22e-02 7.50e-02 6.98e-02 -------- 1.74e-01 2.45e-01 ph/cm2/s
Fluence Band -------- -------- -------- -------- -------- -------- erg/cm2
Error -------- -------- -------- -------- -------- -------- erg/cm2
Peak flux Band -------- -------- -------- -------- -------- -------- ph/cm2/s
Error -------- -------- -------- -------- -------- -------- ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.377 0.077 - - 4.14e-03 1.71e-04 50.650 57
CPL 1.276 0.209 356.9 0.0 4.62e-03 1.01e-03 50.810 56
The chi2 of BB fit is Chi-Squared which shows a significant improvement in the fit over a PL.
Check the BB fit.
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.941 0.228 - - 1.01e-02 1.45e-03 49.550 57
CPL -0.632 1.294 99.9 56.0 4.62e-02 8.69e-02 42.940 56
Model : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index : photon index: E^-{Ph_index} (minus sign is not included in the index)
Ph_90err : 90% error of the photon index
Epeak : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm : normalization at 50 keV in PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2 : Chi-Squared
dof : degree of freedom
=== Table of the duration information ==
Value tstart tstop
T100 59.200 0.000 59.200
T90 54.400 1.600 56.000
T50 30.400 12.800 43.200
Peak 1.000 5.100 6.100
Image
Note1: The mosaic image is made with timebin = 0.2 s; energybin = 15-350 keV
Note2: The mosaic image uses Galactic coordinate.
#RAcent DECcent POSerr Theta Phi Peak_Cts SNR Name
43.122 42.679 0.002 32.546 154.957 0.074 41.046 UNKNOWN
Image time interval: 1.196 to 40.840 [sec]
Lightcurves
Notes:
- 1) The mask-weighted lightcurves have units of either count/det or counts/sec/det, where a det is 0.4 x 0.4 = 0.16 sq cm.
- 2) The verticle lines correspond to following: green dotted lines are T50 interval, black dotted lines are T90 interval, blue solid line(s) is a spacecraft slew start time, and orange solid line(s) is a spacecraft slew end time (for the best duration plot, slew times are marked by green arrows).
- 3) For lightcurves in unit of count rate, time of each bin is in the middle of the bin.
Best duration plot
1 s binning
From T0-310 s to T0+310 s
From T100_start - 20 s to T100_end + 30 s
Full time interval
64 ms binning
Full time interval
From T100_start to T100_end
From T0-5 sec to T0+5 sec
16 ms binning
From T100_start-5 s to T100_start+5 s
8 ms binning
From T100_start-3 s to T100_start+3 s
2 ms binning
From T100_start-1 s to T100_start+1 s
SN=5 or 10 sec. binning (whichever binning is satisfied first)
SN=5 or 10 sec. binning (T < 200 sec)
Spectral Evolution
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) For long bursts, a spectral fit of the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
- 4) For short bursts (T90<1sec), the specrtum is also fit with Blackbody, OTTB, and Double Blackbody.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 59.200 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.37701 ( -0.0767227 0.0765902 )
Norm@50keV : 4.14018E-03 ( -0.00017057 0.000170543 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.65 using 59 PHA bins.
# Reduced chi-squared = 0.8885 for 57 degrees of freedom
# Null hypothesis probability = 7.107980e-01
Photon flux (15-150 keV) in 59.2 sec: 0.501637 ( -0.021906 0.021975 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.37997e-06 ( -1.06906e-07 1.07293e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 59.200 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.27590 ( -0.314306 0.104592 )
Epeak [keV] : 356.927 ( -668.612 -668.612 )
Norm@50keV : 4.61772E-03 ( -0.000389556 0.00163962 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.81 using 59 PHA bins.
# Reduced chi-squared = 0.9073 for 56 degrees of freedom
# Null hypothesis probability = 6.710683e-01
Photon flux (15-150 keV) in 59.2 sec: 0.500042 ( -0.023459 0.022349 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.37127e-06 ( -1.1713e-07 1.0884e-07 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 59.200 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 17.3455 ( )
R^2/D10^2 : 3.44920E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 181.01 using 59 PHA bins.
# Reduced chi-squared = 3.1757 for 57 degrees of freedom
# Null hypothesis probability = 7.906527e-15
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.244e-07 1.057e-08
25- 50 5.593e-07 3.283e-08
50-150 1.209e-06 8.821e-08
15-150 1.893e-06 9.265e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-10.038 -200)
Norm : 2.08552 (-0.0863375 0.0863375)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.33 using 59 PHA bins.
# Reduced chi-squared = 1.216 for 57 degrees of freedom
# Null hypothesis probability = 1.266916e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.074e-07 1.424e-08
25- 50 5.914e-07 2.546e-08
50-150 1.297e-06 6.394e-08
15-150 2.196e-06 1.119e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.53641 (-1.24243 1.43069)
R1^2/D10^2 : 0.373349 (-0.156616 0.315373)
kT2 [keV] : 30.1643 (-4.54071 7.765)
R2^2/D10^2 : 4.39495E-03 (-0.00232204 0.00339033)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.23 using 59 PHA bins.
# Reduced chi-squared = 1.040 for 55 degrees of freedom
# Null hypothesis probability = 3.924561e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.533e-07 4.310e-08
25- 50 5.687e-07 6.829e-08
50-150 1.537e-06 2.492e-07
15-150 2.359e-06 2.836e-07
Peak spectrum fit
Power-law model
Time interval is from 0.000 sec. to 0.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.941008 ( -0.233326 0.223252 )
Norm@50keV : 1.00626E-02 ( -0.0014515 0.00144065 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.55 using 59 PHA bins.
# Reduced chi-squared = 0.8693 for 57 degrees of freedom
# Null hypothesis probability = 7.478667e-01
Photon flux (15-150 keV) in 1 sec: 1.15578 ( -0.167446 0.16834 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.11191e-07 ( -1.62093e-08 1.62825e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 0.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.631674 ( -1.48683 1.10072 )
Epeak [keV] : 99.8967 ( -22.7914 89.1667 )
Norm@50keV : 4.62324E-02 ( -0.0462614 0.127498 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.94 using 59 PHA bins.
# Reduced chi-squared = 0.7668 for 56 degrees of freedom
# Null hypothesis probability = 8.999597e-01
Photon flux (15-150 keV) in 1 sec: 1.08950 ( -0.173046 0.17446 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.05167e-07 ( -1.72951e-08 1.72749e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 0.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 22.6016 (-3.36084 4.28834)
R^2/D10^2 : 4.03503E-02 (-0.0170872 0.0273196)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.75 using 59 PHA bins.
# Reduced chi-squared = 0.7675 for 57 degrees of freedom
# Null hypothesis probability = 9.013693e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.767e-09 1.144e-09
25- 50 2.023e-08 4.310e-09
50-150 7.724e-08 1.985e-08
15-150 1.012e-07 2.041e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-29.6387 -200)
Norm : 4.73460 (-0.702229 0.702229)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.54 using 59 PHA bins.
# Reduced chi-squared = 1.185 for 57 degrees of freedom
# Null hypothesis probability = 1.601715e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.179e-08 6.760e-09
25- 50 2.269e-08 1.269e-08
50-150 4.975e-08 2.803e-08
15-150 8.423e-08 4.748e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 10.2315 (-9.96548 -9.96548)
R1^2/D10^2 : 0.110848 (-0.112534 -0.112534)
kT2 [keV] : 26.2671 (-26.1449 -26.1449)
R2^2/D10^2 : 2.21093E-02 (-0.0223162 0.0387912)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.77 using 59 PHA bins.
# Reduced chi-squared = 0.7777 for 55 degrees of freedom
# Null hypothesis probability = 8.850116e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.961e-09 3.017e-09
25- 50 2.111e-08 1.144e-08
50-150 7.948e-08 4.681e-08
15-150 1.056e-07 5.690e-08
Webpage updated on:
Mon Jul 10 19:25:31 EDT 2017