GRB 151006A
GCN Circular 18475
Subject
GRB 151006A: CALET Gamma-Ray Burst Monitor detection
Date
2015-10-27T00:49:24Z (10 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, K. Senuma,
M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
M. L. Cherry (LSU), S. Ricciarini (U of Florence)
and the CALET collaboration:
The long-duration GRB 151006A (Kocevski et al., GCN Circ. 18398; Cummings et al.,
GCN Circ. 18409; Roberts & Meegan, GCN Circ. 18404; Golenetskii et al., GCN Circ. 18413;
Bhalerao et al., GCN Circ. 18422) triggered the CALET Gamma-Ray Burst Monitor (CGBM)
at 09:54:59.97 UT on 6 October 2015. The clear burst signal was detected by the Soft
Gamma-ray Monitor (SGM; 30 keV - 20 MeV) which is a scintillation detector utilized a BGO
crystal. Due to a large incident angle of the event, no signal was detected by the Hard X-ray
Monitor (HXM; 7 keV - 1 MeV) which is a scintillation detector composed of a LaBr3(Ce) crystal.
The SGM light curve shows two spikes peaking at T0-2s and T0+2s, and the emission ending
around T0+~60s. The T90 duration measured by the SGM data is 63 +- 5 s (30 - 1000 keV).
Currently, CALET is in the commissioning phase. Further information about CALET and
CGBM can be found at http://calet.jp/en/ and http://www.en.yoshida-agu.net/research/calet-gbm
GCN Circular 18422
Subject
GRB 151006A: Astrosat CZTI detection
Date
2015-10-16T11:28:09Z (10 years ago)
From
Varun Bhalerao at IUCAA <varunb@iucaa.in>
V. Bhalerao (IUCAA), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:
Analysis of Astrosat commissioning data showed the presence of GRB 151006A (Kocevski et al. 2015, GCN 18398) in the Cadmium Zinc Telluride Imager. The source was located 60.7 degrees away from the pointing direction and was detected at energies above 60 keV. Modelling the profile as a fast rise and exponential decay, we measure T90 of 65s, 75s, and 50s in 60-80 keV, 80-100 keV and 100-250 keV bands respectively.
In addition, the GRB is clearly detected in a lightcurve created from double events satisfying Compton scattering criteria (Vadawale et al., 2015, A&A, 578, 73). This demonstrates the feasibility of measuring polarisation for brighter GRBs with CZTI.
GCN Circular 18416
Subject
GRB 151006A: Mondy optical upper limit
Date
2015-10-11T10:03:30Z (10 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), E. Klunko (ISTP), A. Volnova (IKI), I. Korobtsev
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up
collaboration:
We observed the field of Swift GRB 151006A (Kocevski et al., GCN 18398)
with AZT-33IK telescope of Sayan observatory (Mondy) starting on Oct. 18
(UT) 16:50:47. We obtained several images in R-filter of 120 s exposure.
Within XRT error circle (Goad et al., GCN 18403) we do not detect
any optical source. Upper limit is following
Date UT start t-T0 Filter Exp. UL (3 sigma)
(mid, days) (s)
2015-10-06 16:50:47 0.31306 R 35*120 22.4
Photometry is based on USNO-B1.0 stars:
USNO-B1.0_id R2
1604-0085829 18.23
1604-0085812 16.90
GCN Circular 18415
Subject
GRB 151006A: MITSuME Akeno optical upper limits
Date
2015-10-09T13:37:39Z (10 years ago)
From
Taketoshi Yoshii at Tokyo Tech <yoshii.t.ac@m.titech.ac.jp>
S.Harita, T.Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi, Y. Yano,
S. Kurita, Y.Ono, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 151006A (D. Kocevski et al. GCN Circular #18398) with the
optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2015-10-06 15:20:15 UT (~4.4 h after the burst).
We did not find any new point source within XRT circle in all three bands.
We obtained following limits for the magnitudes.
T0+[sec] MID-UT T-EXP[sec] g' Rc Ic
---------------------------------------------------------------------------------------
19514 17:24:12.2 9240 >21.3 >20.8 > 19.9
---------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration
GCN Circular 18413
Subject
Konus-Wind observation of GRB 151006A
Date
2015-10-08T11:04:52Z (10 years ago)
From
Anastasia Tsvetkova at Ioffe Institute <tsvetkova@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration, hard-spectrum GRB 151006A
(Swift-BAT trigger #657750: Kocevski et al., GCN 18398;
Cummings et al., GCN 18409;
Fermi GBM detection: Roberts & Meegan, GCN 18404)
triggered Konus-Wind at T0=35697.746 s UT (09:54:57.746).
The burst light curve shows a single FRED-like pulse
with a total duration of ~114 s.
The emission is seen up to ~10 MeV.
As observed by Konus-Wind, the burst
had a fluence of 5.30(-0.87,+0.92)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+2.928 s,
of 5.60(-2.26,+2.23)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst
(measured from T0 to T0+73.984 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.26(-0.23,+0.42),
the high energy photon index beta = -1.73(-0.13,+0.09),
the peak energy Ep = 223(-132,+514) keV,
chi2 = 85/97 dof.
The spectrum near the peak count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.40(-0.06,+0.07),
and Ep = 2600(-1200,+2900) keV (chi2 = 71/98 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -1.7 (chi2 = 71/97 dof).
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB151006_T35697/
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 18411
Subject
GRB 151006A: OSN optical upper limit
Date
2015-10-07T17:43:58Z (10 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates (IAA-CSIC), S. Jeong (IAA-CSIC/SKKU), A. Sota, J. C. Tello (IAA-CSIC),
A.J. Castro-Tirado (IAA-CSIC/UMA), S. B. Pandey (ARIES Nainital) report on behalf
of a larger collaboration:
We observed the field of GRB 151006A (Kocevski et al., GCN Circ. 18398) with the 1.5m
OSN telescope at Observatorio de Sierra Nevada (Spain). The observations
were carried out in the I band on Oct 7.13159-7.17369 (17.24 - 18.25 hours
post bust). We do not detect any new optical source within the enhanced XRT
error circle (Goad et al., GCN Circ. 18403) down to a limiting magnitude of I ~21mag.
GCN Circular 18409
Subject
GRB 151006A: Swift-BAT refined analysis
Date
2015-10-07T15:19:37Z (10 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), N. Gehrels (GSFC),
D. Kocevski (NASA/GSFC/ORAU), H. A. Krimm (GSFC/USRA),
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-239 to T+800 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 151006A (trigger #657750)
(Kocevski, et al., GCN Circ. 18398). The BAT ground-calculated position is
RA, Dec = 147.426, 70.508 deg which is
RA(J2000) = 09h 49m 42.3s
Dec(J2000) = +70d 30' 30.2"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a FRED-like structure that starts at ~T-5 s,
peaks at ~ T+1 s, and ends at ~ T+310 s. T90 (15-350 keV) is 203.9 +- 41.6 sec
(estimated error including systematics).
The time-averaged spectrum from T-4.9 to T+311.2 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.56 +- 0.06. The fluence in the 15-150 keV band is 6.9 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.49 sec in the 15-150 keV band
is 2.6 +- 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/657750/BA/
GCN Circular 18408
Subject
GRB 151006A: MITSuME Okayama Ks-band upper-limit
Date
2015-10-07T02:58:46Z (10 years ago)
From
Kenshi Yanagisawa at OAO/NAOJ <yanagi@oao.nao.ac.jp>
Kenshi Yanagisawa, Daisuke Kuroda, Yasuhiro Shimizu,
Hideyuki Izumiura(OAO/NAOJ), Michitoshi Yoshida (Hiroshima-U),
Kouji Ohta(Kyoto-U) and Nobuyuki Kawai(Tokyo Tech.) report
on behalf of the MITSuME collaboration:
We observed the field of GRB151006A (Kocevski et al., GCN 18398)
in Ks-band with a wide-field near infrared imager at Okayama
Astrophysical Observatory (Japan). The imager has effective
aperture of 0.91 m.
Observations started from 17:22 UT on 6th October, 7.4h after
the BAT trigger, to 18:17 UT. The total exposure of 26.5 min
was successfully obtained.
In our co-add image, we did not find any new point source within
the enhanced XRT error circle (Goad et al., GCN 18403) down
to limiting magnitude of Ks=15.2 (Vega, S/N=10). The photometric
calibration was made against 2MASS field stars.
T0+[sec] MID-UT T-EXP[sec] Ks
---------------------------------------------------
+26,819 17:49 1,590 >15.2
---------------------------------------------------
T0+ : Elapsed time after the burt [sec]
T-EXP: Total Exposure time [sec]
GCN Circular 18407
Subject
GRB 151006A: Swift-XRT refined Analysis
Date
2015-10-06T22:05:02Z (10 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
L.M. McCauley (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester),
P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), V. D'Elia
(ASDC), A. D'ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), B. Sbarufatti
(INAF-OAB/PSU) and D. Kocevski report on behalf of the Swift-XRT team:
We have analysed 11 ks of XRT data for GRB 151006A (Kocevski et al. GCN
Circ. 18398), from 40 s to 29.1 ks after the BAT trigger. The data
comprise 552 s in Windowed Timing (WT) mode (the first 7 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. 18399).
The light curve can be modelled with an initial power-law decay with an
index of alpha=0.3 (+0.7, -1.6), followed by a break at T+64.1 s to an
alpha of 1.377 (+0.020, -0.019).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.45 (+0.06, -0.05). The
best-fitting absorption column is 4.9 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 7.7 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.08 (+0.17, -0.16)
and a best-fitting absorption column of 4.3 (+0.9, -0.8) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.7 x 10^-11 (6.1 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 4.3 (+0.9, -0.8) x 10^21 cm^-2
Galactic foreground: 7.7 x 10^20 cm^-2
Excess significance: 7.1 sigma
Photon index: 2.08 (+0.17, -0.16)
If the light curve continues to decay with a power-law decay index of
1.377, the count rate at T+24 hours will be 4.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x
10^-13 (2.9 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/00657750.
This circular is an official product of the Swift-XRT team.
GCN Circular 18406
Subject
GRB 151006A: Fermi-LAT detection
Date
2015-10-06T21:13:33Z (10 years ago)
From
Daniel Kocevski at GSFC <daniel.kocevski@nasa.gov>
M. Ohno (Hiroshima U.), E. Bissaldi (INFN Bari), G. Vianello (Stanford University),
D. Kocevski (NASA/GSFC) and F. Longo (University & INFN Trieste)
report on behalf of the Fermi-LAT team:
At 09:54:57.83 on October 06, 2015, Fermi-LAT detected high-energy emission
from GRB 151006A, which was also detected by Fermi-GBM (trigger 465818101;
Roberts et al. GCN 18404) and Swift-BAT (Kocevski et al. GCN 18398).
The GBM location was initially inside the LAT field of view at an angle of ~30 degrees
to the LAT boresight. Using the LAT Low Energy (LLE) data selection, over 400 counts above
background were detected within a 30 s interval coinciding with the time of the GBM emission.
This data selection has insufficient spatial resolution to provide a reliable LAT localization.
Processing and analysis of standard data is ongoing.
The Fermi LAT point of contact for this burst is
Masanori Ohno (ohno@hep01.hepl.hiroshima-u.ac.jp<mailto:ohno@hep01.hepl.hiroshima-u.ac.jp>).
The Fermi-LAT is a pair conversion telescope designed to cover
the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between
NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.
GCN Circular 18405
Subject
GRB 151006A: Swift/UVOT Upper Limits
Date
2015-10-06T19:03:04Z (10 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (UCL-MSSL) and D. Kocevski (NASA/GSFC/ORAU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 151006A 36
s after the BAT trigger (Kocevski et al., GCN Circ. 18398).
No optical afterglow consistent with the XRT position (Goad et al. GCN
Circ. 18403) 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 58 208 147 >20.7
u_FC 271 521 246 >19.9
white 58 6351 520 >21.4
v 36 6754 437 >19.8
b 527 6146 236 >20.3
u 271 5941 442 >20.3
w1 5537 5736 197 >19.8
m2 625 5531 235 >19.7
w2 577 6557 432 >20.4
The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.24 in the direction of the
burst (Schlegel et al. 1998).
GCN Circular 18404
Subject
GRB 151006A: Fermi GBM detection
Date
2015-10-06T16:02:36Z (10 years ago)
From
Oliver Roberts at UCD/Fermi <oliver.roberts@ucd.ie>
O.J. Roberts (UCD) and C.Meegan (UAH) report on
behalf of the Fermi GBM Team:
"At 09:54:57.83 UT on 06 October 2015, the Fermi
Gamma-Ray Burst Monitor triggered and located
GRB 151006A (trigger 465818101/151006413), which
was also detected by Swift BAT and XRT
(Kocevski et al. 2015, GCN 18398). The GBM on-ground
location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM
trigger time using the Swift position is 30 degrees.
The GBM light curve consists of a FRED-like peak
with a duration (T90) of about 84 s (50-300 keV).
The time-averaged spectrum from T0+0 s to T0+83.7 s
is best fit by a Band function with Epeak = 227 +/- 53 keV,
alpha = -1.17 +/- 0.07, and beta = -1.68 +/- 0.04
The event fluence (10-1000 keV) in this time interval
is (1.15 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon
flux measured starting from T0+5.24 s in the 10-1000 keV
band is 4.9 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 18403
Subject
GRB 151006A: Enhanced Swift-XRT position
Date
2015-10-06T14:08:27Z (10 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 2266 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 151006A, 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 = 147.42592, +70.50299 which is equivalent
to:
RA (J2000): 09h 49m 42.22s
Dec (J2000): +70d 30' 10.8"
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 Circular 18402
Subject
GRB 151006A: MITSuME Okayama upper limits
Date
2015-10-06T11:52:48Z (10 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of MITSuME and OISTER collaboration:
We observed the field of GRB 151006A (Kocevski et al., GCNC 18398)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2015-10-06 09:56:35 UT (~93 sec after the burst).
We did not find any new point source within the enhanced XRT error circle
(Evans, GCNC 18399) in all the three bands.
Three sigma upper limits of the OT are listed below.
We used GSC2.3 catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' Rc Ic
-----------------------------------------------------
0.00707 10:05:12 540.0 >18.6 >18.6 >18.0
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 18400
Subject
GRB 151006A: Kanata/HOWPol optical imaging polarimetry
Date
2015-10-06T11:05:12Z (10 years ago)
From
Koji Kawabata at HASC,Hiroshima U <kawabtkj@hiroshima-u.ac.jp>
K. S. Kawabata, R. Itoh, M. Kawabata, T. Nakaoka, H. Mori, K. Takaki (Hiroshima
Univ.), and R. Shimotani (Kagawa Univ.) report on behalf of Kanata team:
We performed a series of optical imaging-polarimetry for the optical afterglow
of GRB151006A (Kocevski et al., GCN 18398) from 73 sec after the Swift/BAT
trigger with HOWPol attached to the 1.5-m Kanata telescope at Higashi-Hiroshima
Observatory, Japan.
We could not detect any afterglow within the XRT error circle reported in the
GCN 18398. We obtained the following preliminary upper limits in our first
image (mid-time 88 sec after the trigger) calibrated with UCAC4:
Rc > 17.7
Further analysis is ongoing.
GCN Circular 18399
Subject
GRB 151006A: Prompt enhanced Swift-XRT position
Date
2015-10-06T10:23:24Z (10 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 151006A, we find an
enhanced XRT position of the afterglow: RA, Dec: 147.4260, 70.5027
which is equivalent to:
RA (J2000) = 09 49 42.25
Dec (J2000) = +70 30 09.7
with an uncertainty of 2.3 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/657750.
Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.
GCN Circular 18398
Subject
GRB 151006A: Swift detection of a burst
Date
2015-10-06T10:05:37Z (10 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
D. Kocevski (NASA/GSFC/ORAU), S. D. Barthelmy (GSFC),
P. A. Evans (U Leicester), K. L. Page (U Leicester) and
B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:
At 09:55:01 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 151006A (trigger=657750). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 147.451, +70.509, which is
RA(J2000) = 09h 49m 48s
Dec(J2000) = +70d 30' 31"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a single FRED-like peak
structure with a duration of about 40 sec. The peak count rate
was ~4000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 09:55:50.4 UT, 48.6 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 147.4256, 70.5036 which is equivalent to:
RA(J2000) = +09h 49m 42.14s
Dec(J2000) = +70d 30' 13.0"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 36 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.
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 58 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
0.24.
Burst Advocate for this burst is D. Kocevski (dankocevski 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.)