| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB170803729 |
|
| T0 |
17:30:26.920 UTC |
Fermi_GBM |
| ra |
174.9338° |
Swift |
| decl |
-16.3106° |
Swift |
| pos_error |
5.70e-05° |
Swift |
| T90 |
3.584 s |
Fermi_GBM |
| T90_error |
0.32 s |
Fermi_GBM |
| T90_start |
17:30:26.920 UTC |
Fermi_GBM |
| fluence |
1.89e-06 erg/cm² |
Fermi_GBM |
| fluence_error |
2.44e-08 erg/cm² |
Fermi_GBM |
| T100 |
3.9 s |
|
| GBM_located |
False |
|
| mjd |
57968.72947824074 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB170803729 |
| trigger_name |
bn170803729 |
| ra |
174.9350° |
| decl |
-16.3119° |
| pos_error |
3.65e+00° |
| datum |
2017-08-03 |
| t_trigger |
17:30:27.112 UTC |
| T90 |
3.584 s |
| T90_error |
0.32 s |
| T90_start |
17:30:26.920 UTC |
| fluence |
1.89e-06 erg/cm² |
| fluence_error |
2.44e-08 erg/cm² |
| flux_1024 |
9.14e+00 erg/cm²/s |
| flux_1024_error |
2.51e-01 erg/cm²/s |
| flux_1024_time |
-6.40e-02 erg/cm²/s |
| flux_64 |
1.62e+01 erg/cm²/s |
| flux_64_error |
1.14e+00 erg/cm²/s |
| IPN table |
|---|
| GRB_name |
GRB170803A |
| ra |
174.9500° |
| decl |
-16.3167° |
| pos_error |
5.00e-02° |
| Swift table |
|---|
| GRB_name |
GRB170803A |
| t_trigger |
17:30:27 UTC |
| ra |
174.9338° |
| decl |
-16.3106° |
| pos_error |
5.70e-05° |
| T90 |
3.82 s |
| fluence |
9.80e-07 erg/cm² |
| GCN 21405 table |
|---|
| GRB_name |
GRB170803A |
| GCN_number |
21405 |
| Detection_method |
Swift Det |
| t_trigger |
17:30:27 UTC |
| ra |
174.9500° |
| decl |
-16.3110° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 21405
SUBJECT: GRB 170803A: Swift detection of a burst with an optical counterpart
DATE: 17/08/03 17:42:50 GMT
FROM: David Palmer at LANL
S. J. LaPorte (PSU), A. Cholden-Brown (PSU), J. A. Kennea (PSU),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and
M. H. Siegel (PSU) report on behalf of the Swift Team:
At 17:30:27 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170803A (trigger=766081). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 174.950, -16.311 which is
RA(J2000) = 11h 39m 48s
Dec(J2000) = -16d 18' 38"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multiple-peaked
structure with a duration of about 5 sec. The peak count rate
was ~15000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 17:32:27.0 UT, 120.1 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 174.93532, -16.31155 which is
equivalent to:
RA(J2000) = 11h 39m 44.48s
Dec(J2000) = -16d 18' 41.6"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 50 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.54 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 3
(+2.47/-2.15) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 88 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 11:39:44.11 = 174.93381
DEC(J2000) = -16:18:37.9 = -16.31052
with a 90%-confidence error radius of about 0.75 arc sec. This position is 6.1
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.12 with a 1-sigma error of about 0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.04.
Burst Advocate for this burst is S. J. LaPorte (extragsam AT gmail.com).
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 21406 table |
|---|
| GRB_name |
GRB170803A |
| GCN_number |
21406 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
17:30:27.112 UTC |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 21406
SUBJECT: GRB 170803A: Fermi GBM observation
DATE: 17/08/03 23:03:54 GMT
FROM: Peter Veres at UAH
P Veres and C Meegan (both UAH)
report on behalf of the Fermi GBM Team:
"At 17:30:27.112 UT on 3 August 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170803A (trigger 523474232 / 170803729)
which was also detected by the Swift/BAT (LaPorte et al., GCN 21405).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 40 degrees.
The GBM light curve consists of a single pulse
with a duration (T90) of about 3.6 s (50-300 keV).
The time-averaged spectrum from T0-0.1 s to T0+2.2 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.71 +/- 0.12 and
the cutoff energy, parameterized as Epeak, is 154 +/- 13 keV.
The event fluence (10-1000 keV) in this time interval is
(1.65 +/- 0.076)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.1 s in the 10-1000 keV band
is 9.1 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
|
| GCN 21407 table |
|---|
| GRB_name |
GRB170803A |
| GCN_number |
21407 |
| Detection_method |
Swift-XRT Det |
| ra |
174.9343° |
| decl |
-16.3100° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 21407
SUBJECT: GRB 170803A: Enhanced Swift-XRT position
DATE: 17/08/04 01:08:11 GMT
FROM: Phil Evans at U of Leicester
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 2272 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 170803A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 174.93434, -16.31002 which is equivalent
to:
RA (J2000): 11h 39m 44.24s
Dec (J2000): -16d 18' 36.1"
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
|
| GCN 21408 table |
|---|
| GRB_name |
GRB170803A |
| GCN_number |
21408 |
| Detection_method |
Swift-XRT Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 21408
SUBJECT: GRB 170803A: Swift-XRT refined Analysis
DATE: 17/08/04 03:59:45 GMT
FROM: Phil Evans at U of Leicester
B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), B. Mingo (U. Leicester), A.
Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A.
Cholden-Brown (PSU) and S.J. LaPorte report on behalf of the Swift-XRT
team:
We have analysed 6.1 ks of XRT data for GRB 170803A (LaPorte et al. GCN
Circ. 21405), from 68 s to 30.1 ks after the BAT trigger. The data
comprise 312 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 21407).
The late-time light curve (from T0+5.6 ks) can be modelled with a
power-law decay with a decay index of alpha=1.00 (+/-0.28).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.86 (+0.13, -0.12). The
best-fitting absorption column is 1.3 (+/-0.4) x 10^21 cm^-2, in
excess of the Galactic value of 3.5 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 3.7 x 10^-11 (4.5 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.3 (+/-0.4) x 10^21 cm^-2
Galactic foreground: 3.5 x 10^20 cm^-2
Excess significance: 4.5 sigma
Photon index: 1.86 (+0.13, -0.12)
If the light curve continues to decay with a power-law decay index of
1.00, the count rate at T+24 hours will be 6.3 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.3 x
10^-13 (2.8 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00766081.
This circular is an official product of the Swift-XRT team.
|
| GCN 21411 table |
|---|
| GRB_name |
GRB170803A |
| GCN_number |
21411 |
| Detection_method |
Swift-UVOT Det |
| ra |
174.9338° |
| decl |
-16.3106° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 21411
SUBJECT: GRB 170803A: Swift/UVOT Detection
DATE: 17/08/04 13:04:24 GMT
FROM: Sam Emery at MSSL-UCL
S.W.K. Emery (UCL-MSSL) and S. J. LaPorte (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170803A
88 s after the BAT trigger (LaPorte et al., GCN Circ. 21405).
GRB 170803A was also triggered by Fermi GBM
(Veres and Meegan GCN Circ. 21406)
A fading source consistent with the XRT position
(Beardmore et al., GCN Circ. 21407)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 11:39:44.11 = 174.93380 (deg.)
Dec (J2000) = -16:18:38.0 = -16.31055 (deg.)
with an estimated uncertainty of 0.44 arc sec. (radius, 90% confidence).
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 88 238 147 18.10 +/- 0.06
white 580 2241 322 19.69 +/- 0.12
u_FC 300 550 246 18.58 +/- 0.16
u 775 2366 175 >19.34
b 556 2386 191 20.02 +/- 0.35
uvw1 6216 23821 982 >20.74
uvm2 17025 17715 679 >20.57
uvw2 5602 30135 990 >21.05
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).
|
| GCN 21412 table |
|---|
| GRB_name |
GRB170803A |
| GCN_number |
21412 |
| Detection_method |
Swift-BAT Det |
| ra |
174.9470° |
| decl |
-16.3120° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 21412
SUBJECT: GRB 170803A: Swift-BAT refined analysis
DATE: 17/08/04 14:01:17 GMT
FROM: Amy Lien at GSFC
J. R. Cummings (CPI), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF/USRA), S. J. LaPorte (PSU),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (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+200 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170803A (trigger #766081)
(LaPorte et al., GCN Circ. 21405). The BAT ground-calculated position is
RA, Dec = 174.947, -16.312 deg which is
RA(J2000) = 11h 39m 47.2s
Dec(J2000) = -16d 18' 41.9"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 94%.
The mask-weighted light curve shows a multi-peaked structure that
starts at ~T-0.7 s and ends at ~T+4 s. The main peak occurs at ~T+0.1 s
T90 (15-350 keV) is 3.82 +- 0.23 sec (estimated error including systematics).
The time-averaged spectrum from T-0.69 to T+4.14 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 0.65 +- 0.28,
and Epeak of 100.2 +- 20.5 keV (chi squared 47.53 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 9.8 +- 0.4 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T-0.12 sec in the 15-150 keV band is
6.5 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.39 +- 0.06 (chi squared 71.10 for 57 d.o.f.). 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/766081/BA/
|
| GCN 21418 table |
|---|
| GRB_name |
GRB170803A |
| GCN_number |
21418 |
| Detection_method |
Swift-BAT Det |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 21418
SUBJECT: GRB 170803A: Swift/BAT spectral lag results
DATE: 17/08/05 20:05:59 GMT
FROM: Amy Lien at GSFC
J. P. Norris (BSU), S. D. Barthelmy (GSFC),
S. B. Cenko (GSFC), A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift-BAT team:
We report the spectral lag analysis for GRB 170803A
(LaPorte et al., GCN Circ. 21405) based on the BAT data.
The lag analysis finds a lag of 43 (+12, -12) ms for the
100-350 keV to 25-50 keV band, and 76 (+40, -26) ms for
the 50-100 keV to 15-25 keV band. These values are
consistent with those of long GRBs.
|