| Summary table |
|---|
| Variable |
Value |
Source |
| T0 |
4:23:54 UTC |
GCN_circulars,Swift Det |
| ra |
33.0457° |
Swift |
| decl |
-67.6268° |
Swift |
| pos_error |
2.07e-04° |
Swift |
| T90 |
31.6 s |
Swift |
| T90_start |
4:23:54 UTC |
Swift |
| fluence |
1.90e-06 erg/cm² |
Swift |
| T100 |
31.6 s |
|
| GBM_located |
False |
|
| mjd |
57490.18326388889 |
GCN_circulars,Swift Det |
| IPN table |
|---|
| GRB_name |
GRB160412A |
| ra |
33.1083° |
| decl |
-67.6500° |
| pos_error |
5.00e-02° |
| Swift table |
|---|
| GRB_name |
GRB160412A |
| t_trigger |
4:23:54 UTC |
| ra |
33.0457° |
| decl |
-67.6268° |
| pos_error |
2.07e-04° |
| T90 |
31.6 s |
| fluence |
1.90e-06 erg/cm² |
| GCN 19298 table |
|---|
| GRB_name |
GRB160412A |
| GCN_number |
19298 |
| Detection_method |
Swift Det |
| t_trigger |
4:23:54 UTC |
| ra |
33.1070° |
| decl |
-67.6450° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 19298
SUBJECT: GRB 160412A: Swift detection of a burst
DATE: 16/04/12 04:37:25 GMT
FROM: David Palmer at LANL
S. L. Gibson (U Leicester), A. Y. Lien (GSFC/UMBC),
K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Swift Team:
At 04:23:54 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160412A (trigger=682522). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 33.107, -67.645 which is
RA(J2000) = 02h 12m 26s
Dec(J2000) = -67d 38' 42"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex
peak structure with a duration of about 80 sec. The peak count rate
was ~1800 counts/sec (15-350 keV), at ~13 sec after the trigger.
The XRT began observing the field at 04:25:13.5 UT, 78.8 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 33.0482, -67.6266 which is equivalent to:
RA(J2000) = +02h 12m 11.57s
Dec(J2000) = -67d 37' 35.8"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 104 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy.
The initial flux in the 2.5 s image was 9.17e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 90 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
0.04.
Burst Advocate for this burst is S. L. Gibson (slg44 AT le.ac.uk).
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 19299 table |
|---|
| GRB_name |
GRB160412A |
| GCN_number |
19299 |
| Detection_method |
Swift-XRT Det |
| ra |
33.0459° |
| decl |
-67.6266° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 19299
SUBJECT: GRB 160412A: Enhanced Swift-XRT position
DATE: 16/04/12 10:50:42 GMT
FROM: Phil Evans at U of Leicester
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 2983 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 160412A, 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 = 33.04586, -67.62664 which is equivalent
to:
RA (J2000): 02h 12m 11.01s
Dec (J2000): -67d 37' 35.9"
with an uncertainty of 1.8 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 19301 table |
|---|
| GRB_name |
GRB160412A |
| GCN_number |
19301 |
| Detection_method |
Swift-BAT Det |
| ra |
33.0740° |
| decl |
-67.6360° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 19301
SUBJECT: GRB 160412A: Swift-BAT refined analysis
DATE: 16/04/12 12:42:18 GMT
FROM: Scott Barthelmy at NASA/GSFC
T. N. Ukwatta (LANL) S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), S. L. Gibson (U Leicester), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
(i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160412A (trigger #682522)
(Gibson, et al., GCN Circ. 19298). The BAT ground-calculated position is
RA, Dec = 33.074, -67.636 deg, which is
RA(J2000) = 02h 12m 17.7s
Dec(J2000) = -67d 38' 08.8"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 75%.
The mask-weighted light curves shows several overlapping peaks starting at
~T-10 sec, peaking at ~T+15 sec, and ending at ~T+70 sec.
T90 (15-350 keV) is 31.6 +- 4.0 sec (estimated error including systematics).
The time-averaged spectrum from T-3.35 to T+40.18 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.88 +- 0.08. The fluence in the 15-150 keV band is 1.9 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+14.40 sec in the 15-150 keV band
is 1.6 +- 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/682522/BA/
|
| GCN 19303 table |
|---|
| GRB_name |
GRB160412A |
| GCN_number |
19303 |
| Detection_method |
Swift-XRT Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 19303
SUBJECT: GRB 160412A: Swift-XRT refined Analysis
DATE: 16/04/12 16:51:07 GMT
FROM: Phil Evans at U of Leicester
P.A. Evans (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A.
Maselli (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B.
Sbarufatti (INAF-OAB/PSU), J.P. Osborne (U. Leicester) and S.L. Gibson
report on behalf of the Swift-XRT team:
We have analysed 6.1 ks of XRT data for GRB 160412A (Gibson et al. GCN
Circ. 19298), from 68 s to 30.8 ks after the BAT trigger. The data
comprise 267 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 Goad et al.
(GCN Circ. 19299).
The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=3.14 (+0.20, -0.25). At T+107 s the decay
steepens to an alpha of 5.67 (+0.18, -0.19) before breaking again at
T+377 s to a final decay with index alpha=0.26 (+/-0.08).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 3.05 (+0.11, -0.10). The
best-fitting absorption column is 4.4 (+/-0.3) x 10^21 cm^-2, in
excess of the Galactic value of 4.4 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.4 (+0.4, -0.3) and
a best-fitting absorption column of 2.6 (+1.3, -1.0) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 2.9 x 10^-11 (5.2 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 2.6 (+1.3, -1.0) x 10^21 cm^-2
Galactic foreground: 4.4 x 10^20 cm^-2
Excess significance: 3.4 sigma
Photon index: 2.4 (+0.4, -0.3)
If the light curve continues to decay with a power-law decay index of
0.26, the count rate at T+24 hours will be 0.023 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.6 x
10^-13 (1.2 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00682522.
This circular is an official product of the Swift-XRT team.
|
| GCN 19308 table |
|---|
| GRB_name |
GRB160412A |
| GCN_number |
19308 |
| Detection_method |
Swift-UVOT Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 19308
SUBJECT: GRB 160412A: Swift/UVOT Upper Limits
DATE: 16/04/12 21:09:39 GMT
FROM: Frank Marshall at GSFC
F. E. Marshall (NASA/GSFC) and S. L. Gibson (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 160412A
90 s after the BAT trigger (Gibson et al., GCN Circ. 19298).
No optical afterglow consistent with the enhanced XRT position
(Goad et al. GCN Circ. 19299)
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 90 240 147 >20.4
u_FC 303 552 246 >19.1
white 90 1878 431 >21.1
v 633 2101 175 >19.3
b 558 2026 156 >19.7
u 303 2001 362 >19.5
w1 682 2150 156 >19.8
m2 1063 2125 97 >19.2
w2 608 2076 175 >19.7
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 19314 table |
|---|
| GRB_name |
GRB160412A |
| GCN_number |
19314 |
| Detection_method |
correction |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 19314
SUBJECT: GRB 160412A: GROND upper limits
DATE: 16/04/14 09:54:48 GMT
FROM: Jan Bolmer at MPE/Garching
J. Bolmer, T. Schweyer and J. Greiner (all MPE Garching) report on behalf
of the GROND Team:
We observed the field of GRB 160412A (Swift trigger 682522; Gibson et
al., GCN #19298) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2m MPG telescope at the ESO La Silla
Observatory (Chile).
Observations started at 23:11 UT on 2016-04-12, 18.8 h after the GRB
trigger. They were performed at an average seeing of 2.5“ and at an
average airmass of 2.3.
We detect no source within or close to the Swift-XRT error circle
reported by Goad et al. (GCN #19299).
Based on 36 min of exposure in g'r'i'z' and 37 min in JHK, at a mid-time
of 023:35 UT, we derive the following preliminary upper
limits (in AB system):
g' > 23.5 mag,
r' > 23.6 mag,
i' > 22.9 mag,
z' > 22.7 mag,
J > 20.2 mag,
H > 29.6 mag, and
K_s > 19.7 mag.
Given upper limits are calibrated against GROND zeropoints (g'r'i'z')
as well as 2MASS field stars (JHK_s). No correction for the expected Galactic
foreground extinction corresponding to a reddening of E_(B-V)=0.03 mag in
the direction of the burst (Schlafly & Finkbeiner 2011) has been applied. |