Gamma-ray Burst 190630B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 30 Jun 19 06:02:31 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     912102,   Seg_Num: 0
GRB_RA:          223.669d {+14h 54m 41s} (J2000),
                 223.853d {+14h 55m 25s} (current),
                 223.199d {+14h 52m 48s} (1950)
GRB_DEC:         +41.521d {+41d 31' 16"} (J2000),
                 +41.443d {+41d 26' 33"} (current),
                 +41.723d {+41d 43' 23"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       2689 [cnts]    Image_Peak=162 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       15957 [cnts]
BKG_TIME:        21712.84 SOD {06:01:52.84} UT
BKG_DUR:         8 [sec]
GRB_DATE:        18664 TJD;   181 DOY;   19/06/30
GRB_TIME:        21728.64 SOD {06:02:08.64} UT
GRB_PHI:         -123.80 [deg]
GRB_THETA:         8.07 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     13.41 [sigma]
IMAGE_SIGNIF:    8.43 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -1  +0  +0 +13  +0 
SUN_POSTN:        98.92d {+06h 35m 41s}  +23.18d {+23d 10' 58"}
SUN_DIST:         97.70 [deg]   Sun_angle= -8.3 [hr] (East of Sun)
MOON_POSTN:       63.64d {+04h 14m 33s}  +17.59d {+17d 35' 24"}
MOON_DIST:       118.19 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       70.67, 60.99 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      201.25, 54.47 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
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 = 265.86,-18.37 [deg].

red DSS finding chart ps-file

GCN NOTICE

 
TITLE:           GCN/SWIFT NOTICE 
NOTICE_DATE:     Sun 30 Jun 19 06:03:35 UT 
NOTICE_TYPE:     Swift-XRT Nack-Position 
TRIGGER_NUM:     912102,   Seg_Num: 0 
POINT_RA:        223.675d {+14h 54m 42s} (J2000) 
POINT_DEC:       +41.514d {+41d 30' 50"} (J2000) 
IMG_START_DATE:  18664 TJD;   181 DOY;   19/06/30 
IMG_START_TIME:  21790.72 SOD {06:03:10.72} UT,   62.1 [sec] since BAT Trigger Time 
COUNTS:          6    Min_needed= 20 
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec] 
PH2_ITER:        2    Max_iter_allowed= 4 
ERROR_CODE:      1 
COMMENTS:        SWIFT-XRT Nack Position.   
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 30 Jun 19 06:04:50 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     912102,   Seg_Num: 0
POINT_RA:        223.675d {+14h 54m 42s} (J2000)
POINT_DEC:       +41.514d {+41d 30' 50"} (J2000)
POINT_ROLL:      310.351d
IMG_START_DATE:  18664 TJD;   181 DOY;   19/06/30
IMG_START_TIME:  21794.07 SOD {06:03:14.07} UT,   65.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        0.617
N_STARS:         17
X_OFFSET:        546 [pixels]
Y_OFFSET:        523 [pixels]
X_MAX:           1505 [pixels]
Y_MAX:           1482 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00912102000msufc0065.fits
SUN_POSTN:        98.92d {+06h 35m 41s}  +23.18d {+23d 10' 57"}
SUN_DIST:         97.71 [deg]   Sun_angle= -8.3 [hr] (East of Sun)
MOON_POSTN:       63.66d {+04h 14m 39s}  +17.60d {+17d 35' 43"}
MOON_DIST:       118.19 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       70.65, 60.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.27, 54.47 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 30 Jun 19 06:05:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     912102,   Seg_Num: 0
POINT_RA:        223.675d {+14h 54m 42s} (J2000)
POINT_DEC:       +41.514d {+41d 30' 50"} (J2000)
POINT_ROLL:      310.351d
IMG_START_DATE:  18664 TJD;   181 DOY;   19/06/30
IMG_START_TIME:  21794.07 SOD {06:03:14.07} UT,   65.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        0.617
N_STARS:         17
X_OFFSET:        546 [pixels]
Y_OFFSET:        523 [pixels]
X_MAX:           1505 [pixels]
Y_MAX:           1482 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00912102000msufc0065.fits
SUN_POSTN:        98.92d {+06h 35m 41s}  +23.18d {+23d 10' 57"}
SUN_DIST:         97.71 [deg]   Sun_angle= -8.3 [hr] (East of Sun)
MOON_POSTN:       63.66d {+04h 14m 39s}  +17.60d {+17d 35' 45"}
MOON_DIST:       118.18 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       70.65, 60.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.27, 54.47 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 30 Jun 19 06:06:14 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     912102,   Seg_Num: 0
POINT_RA:        223.675d {+14h 54m 42s} (J2000)
POINT_DEC:       +41.514d {+41d 30' 50"} (J2000)
ROLL:            310.351d
IMG_START_DATE:  18664 TJD;   181 DOY;   19/06/30
IMG_START_TIME:  21794.07 SOD {06:03:14.07} UT,   65.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     583567417
X_OFFSET:        865 [pixels]
Y_OFFSET:        842 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1025
Y_GRB_POS:       1002
BINNING_INDEX:   1
IM_URL:          sw00912102000msuni0089.fits
SUN_POSTN:        98.92d {+06h 35m 41s}  +23.18d {+23d 10' 57"}
SUN_DIST:         97.71 [deg]   Sun_angle= -8.3 [hr] (East of Sun)
MOON_POSTN:       63.67d {+04h 14m 42s}  +17.60d {+17d 35' 55"}
MOON_DIST:       118.18 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       70.65, 60.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.27, 54.47 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 30 Jun 19 06:06:31 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     912102,   Seg_Num: 0
POINT_RA:        223.675d {+14h 54m 42s} (J2000)
POINT_DEC:       +41.514d {+41d 30' 50"} (J2000)
ROLL:            310.351d
IMG_START_DATE:  18664 TJD;   181 DOY;   19/06/30
IMG_START_TIME:  21794.07 SOD {06:03:14.07} UT,   65.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     583567417
X_OFFSET:        865 [pixels]
Y_OFFSET:        842 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1025
Y_GRB_POS:       1002
BINNING_INDEX:   1
IM_URL:          sw00912102000msuni0089.fits
SUN_POSTN:        98.92d {+06h 35m 42s}  +23.18d {+23d 10' 57"}
SUN_DIST:         97.71 [deg]   Sun_angle= -8.3 [hr] (East of Sun)
MOON_POSTN:       63.68d {+04h 14m 42s}  +17.60d {+17d 35' 57"}
MOON_DIST:       118.18 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       70.65, 60.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.27, 54.47 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 30 Jun 19 06:07:06 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     912102,   Seg_Num: 0
GRB_RA:          223.669d {+14h 54m 41s} (J2000),
                 223.853d {+14h 55m 25s} (current),
                 223.199d {+14h 52m 48s} (1950)
GRB_DEC:         +41.521d {+41d 31' 16"} (J2000),
                 +41.443d {+41d 26' 33"} (current),
                 +41.723d {+41d 43' 23"} (1950)
GRB_DATE:        18664 TJD;   181 DOY;   19/06/30
GRB_TIME:        21728.64 SOD {06:02:08.64} UT
TRIGGER_INDEX:   146
GRB_PHI:         -123.80 [deg]
GRB_THETA:         8.07 [deg]
DELTA_TIME:      20.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     13.41 [sigma]
IMAGE_SIGNIF:    8.43 [sigma]
LC_URL:          sw00912102000msb.lc
SUN_POSTN:        98.92d {+06h 35m 42s}  +23.18d {+23d 10' 57"}
SUN_DIST:         97.70 [deg]   Sun_angle= -8.3 [hr] (East of Sun)
MOON_POSTN:       63.68d {+04h 14m 44s}  +17.60d {+17d 36' 02"}
MOON_DIST:       118.17 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       70.67, 60.99 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      201.25, 54.47 [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 = 265.86,-18.37 [deg].

GCN Circular #24913
H. A. Krimm (NSF), N. J. Klingler (PSU), K. L. Page (U Leicester) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 06:02:08 UT, the Swift Burst Alert Telescope (BAT) triggered and located possible GRB 190630B (trigger=912102). Swift slewed immediately to the location. The BAT on-board calculated location is RA, Dec 223.669, +41.521 which is
```
   RA(J2000) = 14h 54m 41s
   Dec(J2000) = +41d 31' 16"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 5 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~0 sec after the trigger. This increase in flux occurred during a rise in background due to entry to the SAA, so it is not immediately clear from the BAT data alone that this is indeed a burst rather than a noise event.
The XRT began observing the field at 06:03:10.7 UT, 62.1 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. We are waiting for the full dataset to detect and localise the XRT counterpart.
UVOT took a finding chart exposure of 66 seconds with the White filter starting 65 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.01.
Due to the high background in the BAT and the lack of immediate counterpart detection in the XRT, the Swift team will not be able to confirm or deny whether this event is a GRB without further data.
Burst Advocate for this burst is H. A. Krimm (hkrimm AT nsf.gov). 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/)
GCN Circular #24914
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB Trigger 912102 starting at Jun. 30, 06:07:18 UT. We detected an uncataloged, faiding optical afterglow candidate at position:
```
RA:  14:54:48.19 (J2000)       
Dec: +41:31:35.84 (J2000)      
```
We estimate the clear band magnitude ~19.9 in out firt clear band image. Observation are on going, multi-band follow-ups are encouraged.
GCN Circular #24918
J. R. Cummings (CPI), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), F. Marshall (GSFC), D. M. Palmer (LANL), 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+50 sec from the recent telemetry downlink, we report further analysis of BAT GRB 190630B (trigger #912102) (Krimm, et al., GCN Circ. 24913). The BAT ground-calculated position is RA, Dec = 223.729, 41.528 deg which is
```
  RA(J2000)  =  14h 54m 55.0s 
  Dec(J2000) = +41d 31' 42.4" 
```
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows a single, weak pulse with a FRED-like shape, starting from T-3 sec, peaking at T+1 sec and fading to background by T+6 sec. We note that data is available until approximately T+250 sec. However, after T+50 sec, the background cannot be properly subtracted due to high background levels arising from Swift�??s entry into the SAA. Therefore we only use data prior to T+50 sec for analysis. The raw light curve shows no sign of any burst activity after the initial pulse. T90 (15-350 keV) is 5.6 +- 0.9 sec (estimated error including systematics).
The time-averaged spectrum from T-1.7 to T+4.7 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.36 +- 0.24. The fluence in the 15-150 keV band is 2.8 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.19 sec in the 15-150 keV band is 1.1 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
In the initial circular for GRB 190630B (Krimm, et al., GCN Circ. 24913), this event was reported as a possible burst. After the more complete analysis carried out here, we conclude that Swift trigger 912102 is indeed a GRB.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/912102/BA/
GCN Circular #24919
K.L. Page (U. Leicester), P.A. Evans (U. Leicester) and F.E. Marshall (NASA/GSFC) report on behalf of the Swift-XRT team:
We have analysed 2.4 ks of XRT data for GRB 190630B, from 47 s to 28.2 ks after the BAT trigger. The data comprise 8 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. Using 307 s of PC mode data and 1 UVOT image, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 223.70024, +41.52614 which is equivalent to:
```
RA (J2000): 14h 54m 48.06s
Dec(J2000): +41d 31' 34.1"
```
with an uncertainty of 3.1 arcsec (radius, 90% confidence).
The light curve can be modelled with a power-law decay with a decay index of alpha=1.32 (+0.08, -0.07).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 3.0 (+1.1, -0.4). The best-fitting absorption column is consistent with the Galactic value of 1.4 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.0 x 10^-11 (3.3 x 10^-11) erg cm^-2 count^-1.
A summary of the WT-mode spectrum is thus:
```
Total column:        1 (+/-20) x 10^20 cm^-2
Galactic foreground: 1.4 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:        3.0 (+1.1, -0.4)
```
If the light curve continues to decay with a power-law decay index of 1.32, the count rate at T+24 hours will be 6.5 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.0 x 10^-14 (2.1 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00912102.
This circular is an official product of the Swift-XRT team.
GCN Circular #24943
GRB 190630B: Swift/UVOT Upper Limits
K. K. Simpson (PSU) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 190630B 65 s after the BAT trigger (Krimm et al., GCN Circ. 24913). No optical afterglow consistent with the optical position (Zheng and Filippenko GCN Circ. 24914) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 65 131 65 >20.5 b 57357 57675 308 >20.69 uvm2 39177 40077 885 >20.36 u 46044 46193 145 >19.89 v 55313 55640 317 >18.87 uvw1 40084 40453 363 >20.02 uvw2 49543 49700 155 >19.09
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #24949
S. Belkin (IKI), A. Kusakin (FAPHI), I. Reva (FAPHI), A. Novichonok (KIAM), A. Pozanenko (IKI), E. Mazaeva (IKI), A. Volnova (IKI), I. Molotov (KIAM) report on behalf of larger GRB IKI FuN collaboration:
We observed the field of GRB 190630B (Krimm, et al., GCN 24913) with Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting on June, 30 (UT) 18:40:21 and Koshka Observatory starting on June, 30 (UT) 20:38:42 in R-filter. We do not detect the afterglow (Zheng, et al., GCN 24914; Zheng, et al., GCN 24931). Preliminary photometry of the field is following
```
Date       UT start t-T0    Filter Exp.  OT    Err. UL   Observatory
                     (mid, days)    (s)

2019-06-30 18:40:21 0.55999 R      6720  n/d   n/d  22.3 TSHAO
2019-06-30 20:38:42 0.63060 R      3780  n/d   n/d  21.9 Koshka
```
The photometry is based on several nearby USNO-B1.0 stars.
```
USNO-B1.0_id R2
1315-0255078 18.06
1314-0253302 17.18
1314-0253267 15.88
```

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Jochen Greiner, last update: 02-Jul-2019 [Disclaimer]