Gamma-ray Burst 181016A

(All information courtesy of the instrument teams.)

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 Oct 18 00:59:23 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     867252,   Seg_Num: 0
GRB_RA:          231.268d {+15h 25m 04s} (J2000),
                 231.567d {+15h 26m 16s} (current),
                 230.475d {+15h 21m 54s} (1950)
GRB_DEC:         -35.279d {-35d 16' 43"} (J2000),
                 -35.344d {-35d 20' 38"} (current),
                 -35.103d {-35d 06' 11"} (1950)
GRB_DATE:        18407 TJD;   289 DOY;   18/10/16
GRB_TIME:        3300.92 SOD {00:55:00.92} UT
TRIGGER_INDEX:   479
GRB_PHI:         -44.10 [deg]
GRB_THETA:        34.66 [deg]
DELTA_TIME:      52.00 [sec]
TRIGGER_DUR:     16.384 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     7.28 [sigma]
IMAGE_SIGNIF:    8.57 [sigma]
LC_URL:          sw00867252000msb.lc
SUN_POSTN:       200.92d {+13h 23m 41s}   -8.80d {-08d 47' 57"}
SUN_DIST:         38.55 [deg]   Sun_angle= -2.0 [hr] (East of Sun)
MOON_POSTN:      286.14d {+19h 04m 34s}  -21.12d {-21d 07' 00"}
MOON_DIST:        49.50 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      335.12, 17.82 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      237.89,-16.06 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 75.59,15.15 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 Oct 18 00:58:56 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     867252,   Seg_Num: 0
GRB_RA:          231.268d {+15h 25m 04s} (J2000),
                 231.567d {+15h 26m 16s} (current),
                 230.475d {+15h 21m 54s} (1950)
GRB_DEC:         -35.279d {-35d 16' 43"} (J2000),
                 -35.344d {-35d 20' 38"} (current),
                 -35.103d {-35d 06' 11"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       38189 [cnts]    Image_Peak=585 [image_cnts]
TRIGGER_DUR:     16.384 [sec] 
TRIGGER_INDEX:   479     E_range: 25-100 keV
BKG_INTEN:       138173 [cnts]
BKG_TIME:        3202.23 SOD {00:53:22.23} UT
BKG_DUR:         64 [sec]
GRB_DATE:        18407 TJD;   289 DOY;   18/10/16
GRB_TIME:        3300.92 SOD {00:55:00.92} UT
GRB_PHI:         -44.10 [deg]
GRB_THETA:        34.66 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     7.28 [sigma]
IMAGE_SIGNIF:    8.57 [sigma]
MERIT_PARAMS:     +1  +0  +0  +4  +2  -1 -100  +0 -78  +0 
SUN_POSTN:       200.92d {+13h 23m 41s}   -8.80d {-08d 47' 56"}
SUN_DIST:         38.55 [deg]   Sun_angle= -2.0 [hr] (East of Sun)
MOON_POSTN:      286.14d {+19h 04m 33s}  -21.12d {-21d 07' 01"}
MOON_DIST:        49.50 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      335.12, 17.82 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      237.89,-16.06 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
COMMENTS:        probably due to it occurring during a Malindi downlink session.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 75.59,15.15 [deg].

GCN Circular #23342
P. D'Avanzo (INAF-OAB), H. A. Krimm (NSF/USRA), D. M. Palmer (LANL), T. Sakamoto (AGU), B. Sbarufatti (PSU) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 00:55:00 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 181016A (trigger=867252). Due to an observing constraint, Swift could not slew to the burst. The BAT on-board calculated location is RA, Dec 231.268, -35.279 which is
```
   RA(J2000) = 15h 25m 04s
   Dec(J2000) = -35d 16' 43"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 40 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~0 sec after the trigger.
Due to a Sun observing constraint, Swift cannot slew to the BAT position until 09:03 UT on 2019 January 03. There will thus be no XRT or UVOT data for this trigger before this time.
Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT brera.inaf.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular #23343
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), P. D'Avanzo (INAF-OAB), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 181016A (trigger #867252) (D'Avanzo, et al., GCN Circ. 23342). The BAT ground-calculated position is RA, Dec = 231.273, -35.307 deg which is
```
  RA(J2000)  =  15h 25m 05.6s 
  Dec(J2000) = -35d 18' 23.6" 
```
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 50%.
The mask-weighted light curve shows a single peak starting at ~T-20 sec, peaking at T+0 sec, and declining to background around T+90 sec. T90 (15-350 keV) is 111.6 +- 26.3 sec (estimated error including systematics).
The time-averaged spectrum from T-18.00 to T+110.14 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.51 +- 0.20. The fluence in the 15-150 keV band is 1.9 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.39 sec in the 15-150 keV band is 0.7 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/867252/BA/

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Jochen Greiner, last update: 16-Oct-2018 [Disclaimer]