| Summary table |
|---|
| Variable |
Value |
Source |
| T0 |
8:42:38 UTC |
GCN_circulars,Swift Det |
| ra |
119.2402° |
Swift |
| decl |
-66.9704° |
Swift |
| pos_error |
4.56e-04° |
Swift |
| T90 |
262.0 s |
Swift |
| T90_start |
8:42:38 UTC |
Swift |
| fluence |
2.80e-06 erg/cm² |
Swift |
| T100 |
262.0 s |
|
| GBM_located |
False |
|
| mjd |
59280.36293981481 |
GCN_circulars,Swift Det |
| IPN table |
|---|
| GRB_name |
GRB210307A |
| ra |
119.1917° |
| decl |
-66.9667° |
| pos_error |
5.00e-02° |
| Swift table |
|---|
| GRB_name |
GRB210307A |
| t_trigger |
8:42:38 UTC |
| ra |
119.2402° |
| decl |
-66.9704° |
| pos_error |
4.56e-04° |
| T90 |
262.0 s |
| fluence |
2.80e-06 erg/cm² |
| GCN 29610 table |
|---|
| GRB_name |
GRB210307A |
| GCN_number |
29610 |
| Detection_method |
Swift Det |
| t_trigger |
8:42:38 UTC |
| ra |
119.1900° |
| decl |
-66.9630° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 29610
SUBJECT: GRB 210307A: Swift detection of a burst
DATE: 21/03/07 09:04:30 GMT
FROM: Elena Ambrosi at INAF-IASF
E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC),
A. D'Ai (INAF-IASFPA), N. J. Klingler (PSU), K. L. Page (U Leicester)
and T. Sakamoto (AGU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 08:42:38 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 210307A (trigger=1036139). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 119.190, -66.963 which is
RA(J2000) = 07h 56m 46s
Dec(J2000) = -66d 57' 45"
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 120 sec. The peak count rate
was ~1300 counts/sec (15-350 keV), at ~3 sec after the trigger.
The XRT began observing the field at 96.2 s seconds after
the BAT trigger. Using promptly downlinked data we find an
uncatalogued X-ray source with a position: RA, Dec 119.239583,
-66.969694 which is equivalent to:
RA(J2000) = 07 56 57.5
Dec(J2000) = -66 58 10.9
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 73.8 arcsec 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.
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 100 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 100% of
the XRT 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
XRT 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
0.138.
This source lies within the current (Sector 35) field-of-view of TESS camera 4.
Burst Advocate for this burst is E. Ambrosi (elena.ambrosi AT 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/)
|
| GCN 29613 table |
|---|
| GRB_name |
GRB210307A |
| GCN_number |
29613 |
| Detection_method |
Optical |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 29613
SUBJECT: GRB 210307A: LCO Optical Upper Limits
DATE: 21/03/07 13:44:16 GMT
FROM: Robert Strausbaugh at U. of the Virgin Islands
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:
We observed Swift GRB 210307A (Ambrosi et al., GCN 29610) with the LCO 1-m Sinistro instrument at the Sutherland Observatory, South Africa site, on March 7, from 09:28 to 09:59 UT (corresponding to 0.60 to 1.18 hours from the GRB trigger time) with the Bessel R and I filters.
We performed a series of 4x240s exposures in R and I. We do not detect an uncatalogued optical source in either band in single frames, or in stacked images at a location consistent the initial XRT detection (Ambrosi et al., GCN 29610). Using the USNO-B.1 catalog as reference, we calculate the following upper limits:
R > 20.72
I > 20.66
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682
|
| GCN 29624 table |
|---|
| GRB_name |
GRB210307A |
| GCN_number |
29624 |
| Detection_method |
Swift-XRT Other |
| ra |
119.2383° |
| decl |
-66.9709° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 29624
SUBJECT: GRB 210307A: Swift-XRT refined Analysis
DATE: 21/03/08 16:42:03 GMT
FROM: Elena Ambrosi at INAF-IASF
A. D'Ai (INAF-IASFPA), J. D. Gropp (PSU), J.A. Kennea (PSU), A.
Tohuvavohu (U. Toronto), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB) and E.
Ambrosi (INAF-IASFPA) report on behalf of the Swift-XRT team:
We have analysed 7.0 ks of XRT data for GRB 210307A (Ambrosi et al. GCN
Circ. 29610), from 97 s to 40.0 ks after the BAT trigger. The data
comprise 149 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. Using 2981 s of PC mode data and 3 UVOT
images, we find an enhanced XRT position (using the XRT-UVOT alignment
and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =
119.23831, -66.97092 which is equivalent to:
RA (J2000): 07h 56m 57.19s
Dec(J2000): -66d 58' 15.3"
with an uncertainty of 1.5 arcsec (radius, 90% confidence).
The light curve can be modelled with a series of power-law decays
followed
by a plateau. The initial decay index is alpha= : 2.11 (+0.10, -0.11).
At T= T0+242.1 s the decay index is alpha=7.88 (+0.12, -2.58) before
breaking again at T=T0+280.5 s with an index alpha= 3.2 (+0.6, -0.4).
After T>T0+10^4 s the lightcurve is in a long lasting plateau phase.
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.520 (+0.035, -0.026). The
best-fitting absorption column is consistent with the Galactic value
of 1.4 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has
a photon index of 1.75 (+0.16, -0.14) and a best-fitting absorption
column of 1.75 (+0.61, -0.30) x 10^21 cm^-2. The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum is 4.0 x 10^-11 (4.9 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.75 (+0.61, -0.30) x 10^21 cm^-2
Galactic foreground: 1.4 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.75 (+0.16, -0.14)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01036139.
This circular is an official product of the Swift-XRT team.
|
| GCN 29629 table |
|---|
| GRB_name |
GRB210307A |
| GCN_number |
29629 |
| Detection_method |
Swift-UVOT Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 29629
SUBJECT: GRB 210307A: Swift/UVOT Upper Limits
DATE: 21/03/08 23:38:27 GMT
FROM: Mike Siegel at PSU/Swift MOC
M. H. Siegel (PSU) and E. Ambrosi (INAF-IASFPA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210307A
100 s after the BAT trigger (Ambrosi et al., GCN Circ. 29610).
No optical afterglow consistent with the XRT position
(Ambrosi et al. GCN Circ. 29610)
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 first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 100 250 147 >20.9
u_FC 313 562 246 >20.6
white 100 786 186 >21.1
v 642 836 39 >19.3
b 568 761 39 >19.9
u 313 736 265 >20.6
w1 692 711 19 >19.6
m2 667 687 19 >18.7
w2 618 812 39 >19.9
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.138 in the direction of the burst
(Schlegel et al. 1998).
|
| GCN 29632 table |
|---|
| GRB_name |
GRB210307A |
| GCN_number |
29632 |
| Detection_method |
Swift-BAT Det |
| ra |
119.2440° |
| decl |
-66.9650° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 29632
SUBJECT: GRB 210307A: Swift-BAT refined analysis
DATE: 21/03/09 03:07:58 GMT
FROM: Takanori Sakamoto at AGU
C. B. Markwardt (GSFC), E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), 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-239 to T+700 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 210307A (trigger #1036139)
(Ambrosi, et al., GCN Circ. 29610). The BAT ground-calculated position is
RA, Dec = 119.244, -66.965 deg which is
RA(J2000) = 07h 56m 58.5s
Dec(J2000) = -66d 57' 54.3"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 79%.
The mask-weighted light curve shows two isolated peaks. The initial peak starts
at T-30 sec, peaks at T0 and ends at T+40 sec. The second peak starts at
T+110 sec, peaks at T+118 sec and ends at T+150 sec. T90 (15-350 keV) is
262 +- 83 sec (estimated error including systematics).
The time-averaged spectrum from T-159.61 to T+174.53 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.56 +- 0.16. The fluence in the 15-150 keV band is 2.8 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.27 sec in the 15-150 keV band
is 1.0 +- 0.2 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/1036139/BA/
|