GRB180721A: Summary Image Light curves Spectra Distribution Others

Analysis Summary

Notes:

• 1) No attempt has been made to eliminate the non-significant decimal places.
• 2) This batgrbproduct analysis is done using the HEASARC data.
• 3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Aug  6 18:17:04 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger849018
======================================================================

  Trigger: 00849018      Segment: 000

  BAT Trigger Time: 553864029.696   [s; MET]
      Trigger Stop: 553864030.72   [s; MET]
               UTC: 2018-07-21T11:06:48.396880    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 347.694926138303   Dec: 4.87966224106747  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.61
     Image Trigger?:     NO
     Rate S/N Ratio:     14.2828568570857  [ if not an image trigger ]
     Image S/N Ratio:    7.61

  Analysis Position:   [ source = BAT ]
    RA: 347.694926138303   Dec: 4.87966224106747  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 347.707005927865   Dec: 4.87392841792597  [deg; J2000]  
        { 23h 10m 49.7s , +04d 52' 26.1" }
         +/- 1.8277119833615 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.853226348159027 [arcmin] (formal 1-sigma fit error)
    SNR: 12.8518141957971
 
  Angular difference between the analysis and refined position is 0.799923 arcmin
 
  Partial Coding Fraction: 1.015625    [ including projection effects ]

  Duration
     T90: 47.6000000238419 +/- 2.98665041218178
        Measured from: 0.0839999914169312
                   to: 47.6840000152588     [s; relative to TRIGTIME]
     T50: 14.6279999017715 +/- 26.9649005406666
        Measured from: 2.69200003147125
                   to: 17.3199999332428     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 1.81599998474121     
                   to: 2.81599998474121     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.391999959945679     
                   to: 48.9160000085831     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.188118   0.349896   0.278230   0.086891
           0.040422   0.042203   0.036731   0.031634 [error]
 Peak      0.023878   0.045055   0.032743   0.013376
           0.005990   0.006504   0.005760   0.004635 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   49.308   -0.392   48.916
T90    47.600    0.084   47.684
T50    14.628    2.692   17.320
Peak    1.000    1.816    2.816
 
 
====== Spectral Analysis Summary =====================================
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^{Ph_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 both the PL model and CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedo
 
=== Time-averaged spectral analysis ===
(Best model with acceptable fit: PL)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -1.256    -0.221      0.225       -           -               -         1.21e-03     -1.56e-04          1.56e-04      52.530   57
CPL     -0.757    -0.670      1.093      127.875     -57.276      -127.875      2.13e-03     -1.05e-03          5.02e-03      51.610   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: PL)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -1.207     -0.263     0.269       -           -               -         7.50e-03     -1.18e-03          1.18e-03      58.150   57
CPL     -0.636     -0.911     1.463      120.411     -56.656      -120.411      1.46e-02     -8.03e-03          6.51e-02      57.330   56
 
 
=== 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         PL   6.04e-08  1.29e-07  2.16e-07  8.25e-07  5.94e-07  1.23e-06   erg/cm2
      90%_error_low -1.37e-08 -1.85e-08 -3.45e-08 -2.54e-07 -8.60e-08 -2.82e-07   erg/cm2
      90%_error_hi   1.46e-08  1.82e-08  3.42e-08  3.25e-07  8.70e-08  3.43e-07   erg/cm2
Peak flux       PL   2.33e-01  2.79e-01  2.42e-01  3.58e-01  8.81e-01  1.11e+00   ph/cm2/s
      90%_error_low -6.41e-02 -5.01e-02 -4.53e-02 -1.21e-01 -1.40e-01 -1.86e-01   ph/cm2/s
      90%_error_hi   6.91e-02  4.92e-02  4.47e-02  1.56e-01  1.41e-01  1.92e-01   ph/cm2/s
 
Fluence        CPL   5.53e-08  1.36e-07  2.24e-07  4.03e-07  5.71e-07  8.17e-07   erg/cm2
      90%_error_low -1.65e-08 -2.19e-08 -3.78e-08 -2.74e-07 -9.67e-08 -2.90e-07   erg/cm2
      90%_error_hi   1.70e-08  2.31e-08  3.89e-08  6.57e-07  9.58e-08  5.28e-07   erg/cm2
Peak flux      CPL   2.11e-01  2.96e-01  2.54e-01  1.88e-01  8.63e-01  9.49e-01   ph/cm2/s
      90%_error_low -7.58e-02 -5.88e-02 -5.08e-02 -1.88e-01 -1.46e-01 -2.06e-01   ph/cm2/s
      90%_error_hi   7.91e-02  6.38e-02  5.27e-02  2.17e-01  1.45e-01  2.74e-01   ph/cm2/s
 
======================================================================

Image

Pre-slew 15.0-350.0 keV image (Event data)

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  347.7070     4.8739   0.0150     5.1529  -177.8834         0.6553221     12.852 TRIG_00849018                 
 
Foreground time interval of the image:
 -0.392  19.605 (delta_t =  19.997 [sec])
Background time interval of the image:
-239.696  -0.392 (delta_t = 239.304 [sec])

Light Curves

Note: 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.

Full-time range; 1 s binning

Other quick-look light curves:

• 64 ms binning (zoomed)
• 16 ms binning (zoomed)
• 8 ms binning (zoomed)
• 2 ms binning (zoomed)
• SN=5 or 10 s binning (full-time range)
• Raw light curve

Spectra

Notes:

• 1) The fitting includes the systematic errors.
• 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using 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.

Time averaged spectrum fit using the average DRM

Power-law model

Time interval is from   -0.392 sec. to   48.916 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.25642     ( -0.221323   0.224546 )
Norm@50keV  : 1.20549E-03    ( -0.000156342   0.00015608 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          52.53 using 59 PHA bins.
# Reduced chi-squared =         0.9217 for     57 degrees of freedom 
# Null hypothesis probability =   6.430922e-01
 
Photon flux (15-150 keV)    in 49.31 sec: 0.142728 ( -0.018802  0.018835 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.93969e-07 ( -8.59902e-08  8.69966e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.392 sec. to   48.916 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.756874     ( -0.670011   1.09284 )
Epeak [keV] : 127.875      ( -57.2748 -127.874 )
Norm@50keV  : 2.12987E-03    ( -0.00104658   0.00502338 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.61 using 59 PHA bins.
# Reduced chi-squared =         0.9217 for     56 degrees of freedom 
# Null hypothesis probability =   6.414416e-01
 
Photon flux (15-150 keV)    in 49.31 sec: 0.139783 ( -0.019659  0.01956 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.71365e-07 ( -9.66915e-08  9.57723e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    1.816 sec. to    2.816 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.20735     ( -0.26328   0.268923 )
Norm@50keV  : 7.49900E-03    ( -0.00118294   0.0011808 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.15 using 59 PHA bins.
# Reduced chi-squared =          1.020 for     57 degrees of freedom 
# Null hypothesis probability =   4.328866e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.881153 ( -0.140406  0.140597 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.59329e-08 ( -1.34228e-08  1.36139e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    1.816 sec. to    2.816 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.636364     ( -0.911124   1.46262 )
Epeak [keV] : 120.411      ( -56.6719 -120.427 )
Norm@50keV  : 1.45716E-02    ( -0.00802312   0.0650766 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.33 using 59 PHA bins.
# Reduced chi-squared =          1.024 for     56 degrees of freedom 
# Null hypothesis probability =   4.254969e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.863229 ( -0.146032  0.144891 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.24303e-08 ( -1.56523e-08  1.51467e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 47.6 sec.
Hardness ratio (energy fluence ratio) = 1.67436432299

S(15-50 keV) vs. S(50-150 keV) plot

S(15-50 keV)  = 1.8939849e-07
S(50-150 keV) = 4.045702e-07

The dash-dotted line and the dashed line traces the fluences calculated from the Band function with Epeak = 15 and 150 keV, respectively. Both lines assume a canonical values of alpha = -1 and beta = -2.5.

Mask shadow pattern

IMX = -9.011741394393637E-02, IMY = 3.330606477325693E-03

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

Time interval of the image:
-239.696000 -0.392000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.0482  40.9491    8.5  55.6  168.8  -1.6915  -1.4    2.8	Cyg X-3                       
326.0775  38.4459    3.4  44.0  179.4  -1.4493  -3.4    8.7	Cyg X-2                       
  3.2584 -42.9055    2.5  44.7   12.4   1.8085   4.7 ------	UNKNOWN                       
359.2477  -9.5791    2.5  13.5  -17.2   0.9766   4.7  576.5	UNKNOWN                       
 20.4249 -38.0211    2.5  47.5   -6.6   1.7428   4.5 ------	UNKNOWN                       
 32.2938 -42.9078    3.3  57.4   -9.5   3.7520   3.5 ------	UNKNOWN                       
 12.2930  11.9418    3.1  25.2  -92.3   1.0664   3.7 ------	UNKNOWN                       
 27.3883 -20.3829    3.0  42.1  -32.1   1.2855   3.8 ------	UNKNOWN                       

Pre-slew background subtracted image of 15-350 keV band

Time interval of the image:
-0.392000 19.604590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.1681  41.0447   73.3  55.6  168.9  -0.0497  -0.2    6.1	Cyg X-3                       
326.0227  38.3941    7.1  44.0  179.3   0.1601   1.6    8.2	Cyg X-2                       
347.7071   4.8739    0.9   5.2 -177.9   0.6552  12.8 ------	UNKNOWN                       
 12.6728  45.5359    3.1  49.6 -132.7   1.0039   3.8 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
43.204590 96.044000
97.304000 962.452000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.7034  35.0803   13.4  53.5  161.5   3.0618   0.9    9.2	Cyg X-1                       
308.0451  40.8810    5.7  50.5  171.9   4.4478   2.0    5.2	Cyg X-3                       
326.2305  38.3436    6.3  38.7 -176.7   1.6941   1.8    3.1	Cyg X-2                       
342.0786 -39.6582    3.5  44.8   36.8   5.8670   3.3 ------	UNKNOWN                       
343.3238 -11.2713    2.4  16.7   45.7   3.1225   4.9 ------	UNKNOWN                       
316.2732  40.0811    2.6  45.2  176.4   6.1715   4.4 ------	UNKNOWN                       
309.4217  45.4984    3.0  52.5  177.4   8.9307   3.9 ------	UNKNOWN                       
314.8907  44.4172    2.8  48.9  179.7   6.4585   4.1 ------	UNKNOWN                       
 26.9699 -31.3103    3.9  52.1  -12.7   4.6390   3.0 ------	UNKNOWN                       
 23.4218  28.2403    5.4  41.2  -98.0   7.3919   2.2 ------	UNKNOWN