batgrbproduct analysis for trigger=745797

Analysis for Trigger 745797

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) Some mask-weighted light curve plots might be missing because the time range is not completely covered by the event data range.

Special note:

Due to the low partial coding fraction of this burst, the light curves and burst durations are created using the special DETECTION mask aperture. However, the spectral analysis is done using the default FLUX aperture for more accurate results, and thus the spectral analysis is only available after T+56.7 s (see figure below), when the burst came into the BAT calibrated field of view.

FLUX-mask-weighted light curve (pcodethresh=0.05; aperture=CALDB:FLUX)

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Wed Apr 26 14:19:58 EDT 2017
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger745797
======================================================================

  Trigger: 00745797      Segment: 000

  BAT Trigger Time: 513110407.296   [s; MET]
      Trigger Stop: 513110415.488   [s; MET]
               UTC: 2017-04-05T18:39:48.432100    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 219.810293944594   Dec: -25.24359290963  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.82
     Image Trigger?:     NO
     Rate S/N Ratio:     57.5325994545701  [ if not an image trigger ]
     Image S/N Ratio:    9.82

  Analysis Position:   [ source = BAT ]
    RA: 219.810293944594   Dec: -25.24359290963  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 219.82396483382   Dec: -25.2364074660541  [deg; J2000]  
        { 14h 39m 17.8s , -25d 14' 11.1" }
         +/- 1.31214961623829 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.471966533934874 [arcmin] (formal 1-sigma fit error)
    SNR: 20.633396604929



  Partial Coding Fraction: 0.06933594    [ including projection effects ]

  Duration
     T90: 165.31200003624 +/- 32.8929220435928
        Measured from: -16.8159999847412
                   to: 148.496000051498     [s; relative to TRIGTIME]
     T50: 47.5200000405312 +/- 2.54092891581977
        Measured from: 0.751999974250793
                   to: 48.272000014782     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 4.30799996852875     
                   to: 5.30799996852875     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -27.1040000319481     
                   to: 242.495999991894     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     6.726083  11.928841  12.148617   3.838516
           0.312249   0.314560   0.289388   0.228585 [error]
 Peak      0.214446   0.306150   0.378312   0.076191
           0.036772   0.041449   0.043702   0.031248 [error]

     [ fluence units of on-axis counts / fully illuminated detector ] 

======================================================================

=== 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 5.30e-07 9.66e-07 1.35e-06 3.96e-06 3.88e-06 6.81e-06   erg/cm2
              Error 6.25e-08 6.55e-08 1.15e-07 7.40e-07 2.75e-07 8.15e-07   erg/cm2
Peak flux Power-law -------- -------- -------- -------- -------- --------   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   ph/cm2/s
 
Fluence   Cutoff-PL 5.30e-07 9.66e-07 1.34e-06 3.94e-06 3.91e-06 6.87e-06   erg/cm2
              Error 0.00e+00 0.00e+00 1.15e-07 0.00e+00 2.75e-07 9.45e-07   erg/cm2
Peak flux Cutoff-PL -------- -------- -------- -------- -------- --------   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   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    1.515    0.119    -      -           2.20e-03 1.43e-04   63.350 57
CPL   1.516    0.137    9999.4    0.0      2.21e-03 6.41e-04   63.370 56
 
 
(1-s peak is outside the event data range; spectral analysis not available)
 
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  269.600  -27.104  242.496
T90   165.312  -16.816  148.496
T50    47.520    0.752   48.272
Peak    1.000    4.308    5.308

Click here for the BAT GCN circular template

Special notes of this burst

Image

15.0-350.0 keV image (Event data with DETECTION mask)

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  219.8240   -25.2364   0.0094    41.3808    77.7865        28.5629485     20.633 TRIG_00745797                 
 
Foreground time interval of the image:
-27.104  50.605 (delta_t =  77.709 [sec])
Background time interval of the image:
-131.195 -27.104 (delta_t = 104.091 [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.
3) For lightcurves in unit of count rate, time of each bin is in the middle of the bin.

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)

Quad-rate summed light curves (from T0-300s to T0+1000s)

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 an average DRM

Power-law model

Time interval is from   56.700 sec. to  242.496 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.51480     ( -0.118421   0.118727 )
Norm@50keV  : 2.20437E-03    ( -0.000143329   0.000142976 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.35 using 59 PHA bins.
# Reduced chi-squared =          1.111 for     57 degrees of freedom 
# Null hypothesis probability =   2.624303e-01
 
Photon flux (15-150 keV)    in 185.8 sec: 0.276308 ( -0.018512  0.018569 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.87664e-06 ( -2.73299e-07  2.7496e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   56.700 sec. to  242.496 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.51618     ( -0.157876   0.116146 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 2.20664E-03    ( -0.000507137   0.000774694 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.37 using 59 PHA bins.
# Reduced chi-squared =          1.132 for     56 degrees of freedom 
# Null hypothesis probability =   2.325820e-01
 
Photon flux (15-150 keV)    in 185.8 sec: 0.277438 ( -0.023788  0.021511 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.9136e-06 ( -3.11581e-07  2.37047e-07 ) ergs/cm2

Band function

Time interval is from   56.700 sec. to  242.496 sec.
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -1.02757   ( 1.02913   1.02913 )
beta        : -1.53310    ( -0.173372   0.133229 )
Epeak [keV] : 56.9407      ( -53.6627 -53.6627 )
Norm@50keV   : 4.78800E-03    ( -0.00301462   255799 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.12 using 59 PHA bins.
# Reduced chi-squared =          1.148 for     55 degrees of freedom 
# Null hypothesis probability =   2.111987e-01
 
Photon flux (15-150 keV)    in 185.8 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]    : 15.4139  (  )
R^2/D10^2   : 2.71644E-02  (   )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =         145.60 using 59 PHA bins.
# Reduced chi-squared =         2.5544 for     57 degrees of freedom 
# Null hypothesis probability =   1.080687e-09
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.499e-07   3.103e-08
25- 50  1.018e-06   9.392e-08
50-150  1.665e-06   2.067e-07
15-150  2.932e-06   2.397e-07

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (-37.8363      -200)
Norm        : 1.12253       (-0.0720918     0.0720918)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          67.05 using 59 PHA bins.
# Reduced chi-squared =          1.176 for     57 degrees of freedom 
# Null hypothesis probability =   1.704699e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.212e-07   3.874e-08
25- 50  1.003e-06   9.141e-08
50-150  2.199e-06   4.810e-07
15-150  3.723e-06   6.354e-07

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 6.97273        (-1.11264      1.29837)
R1^2/D10^2  : 0.324599        (-0.145308      0.28888)
kT2 [keV]   : 31.6654        (-6.06891      11.0321)
R2^2/D10^2  : 1.91091E-03    (-0.00114478   0.00199572)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.75 using 59 PHA bins.
# Reduced chi-squared =          1.123 for     55 degrees of freedom 
# Null hypothesis probability =   2.474991e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.230e-07   1.231e-07
25- 50  9.770e-07   1.697e-07
50-150  2.453e-06   6.998e-07
15-150  3.953e-06   9.773e-07

S(25-50 keV) vs. S(50-100 keV) plot

S(25-50 keV)  = 9.66e-07
S(50-100 keV) = 1.35e-06

T90 vs. Hardness ratio plot

T90                                   = 165.31200003624 sec.
Hardness ratio (energy fluence ratio) = 1.39752

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 1.4405
Count Ratio (50-100 keV) / (15-25 keV) = 1.07452

Mask shadow pattern (with DETECTION mask)

IMX = 1.863853558528538E-01, IMY = -8.610831229835769E-01

TIME vs. PHA plot around the beginning of event data (event_start to event_start+0.64s) with DETECTION mask

TIME vs. DetID plot around the beginning of event data (event_start to event_start+0.64s) with DETECTION mask

100 us light curve (15-350 keV; (event_start to event_start+0.64s)

Spacecraft aspect plot

Bright source in the event data image

Event data image of 15-350 keV band

Time interval of the image:
-27.104000 50.604600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
245.0193 -15.5905    4.4  23.8  113.6  -0.6572  -2.6    3.8	Sco X-1                       
256.1332 -38.0218    0.0  12.4   34.8  -0.1799  -1.1   12.7	4U 1700-377                   
256.2902 -36.2461    0.0  11.2   41.0   0.1280   0.7   12.7	GX 349+2                      
262.8677 -24.5779    0.0   5.4  137.5  -0.4946  -2.8   12.7	GX 1+4                        
264.5410 -44.4380    7.3  15.5   -1.0  -0.2661  -1.6    8.7	4U 1735-44                    
268.2219  -1.5752   23.6  27.5  177.9  -0.1003  -0.5   11.4	SW J1753.5-0127               
270.1271 -25.0954    4.4   5.1 -144.8  -0.4512  -2.6    8.6	GX 5-1                        
270.2859 -25.7696    7.7   4.7 -138.2   0.2708   1.5    1.8	GRS 1758-258                  
274.0533 -14.0183    6.8  16.6 -159.1  -0.3009  -1.7    3.0	GX 17+2                       
275.8760 -30.2177    9.6   8.3  -85.2  -0.2052  -1.2    9.3	H1820-303                     
285.1141 -24.7743    3.2  17.2 -105.8  -0.5875  -3.6    9.7	HT1900.1-2455                 
288.8859  11.0761    8.4  45.6 -154.3  -0.3515  -1.4    9.4	GRS 1915+105                  
263.0403 -33.8545   81.6   5.7   23.8  -0.0239  -0.1    2.8	GX 354-0                      
224.0955 -16.1367    3.4  40.9   92.9   4.1724   3.4 ------	UNKNOWN                       
219.8240 -25.2364    0.6  41.4   77.8  28.5590  20.6 ------	UNKNOWN                       
283.2185 -26.1987    2.5  15.1 -102.6   0.7911   4.7 ------	UNKNOWN

Webpage updated on:
Wed Apr 26 16:41:20 EDT 2017