GRB 141109A
GCN Circular 17072
Subject
GRB 141109A: further VLA observations
Date
2014-11-18T02:18:28Z (11 years ago)
From
Alessandra Corsi at Texas Tech U <alessandra.corsi@ttu.edu>
A. Corsi and D.R. Bhakta (Texas Tech. U.) report on behalf of a larger collaboration:
We imaged again the position of GRB 141109A (D'Avanzo et al., GCN 17037) with
the Karl G. Jansky Very Large Array (VLA) from 2.4 d to 8.3 d after the BAT trigger.
For the radio counterpart consistent with the location of the GRB NIR, optical, and
X-ray afterglows (Covino et al., GCN 17039; Xu et al., GCN 17040; Osborne et al.
GCN 17043; Corsi, GCN 17070), we estimate the following preliminary fluxes:
Mean Epoch (d) | Freq. (GHz) | Flux (uJy) | map rms (uJy)
-------------------------
2.4 | 21.8 | 51 | 9
-------------------------
6.3 | 14.0 | 50 | 6
-------------------------
8.3 | 6.2 | 57 | 6
GCN Circular 17070
Subject
GRB 141109A: VLA detection
Date
2014-11-16T22:57:57Z (11 years ago)
From
Alessandra Corsi at Texas Tech U <alessandra.corsi@ttu.edu>
A. Corsi (Texas Tech U.) reports on behalf of a larger collaboration:
We imaged the position of GRB 141109A (D'Avanzo et al., GCN 17037) with the
Karl G. Jansky Very Large Array (VLA) in K-band at about 7.5 hours after the burst.
A provisional reduction shows a source consistent with the location of the GRB NIR,
optical, and X-ray afterglows (e.g., Covino et al., GCN 17039; Xu et al., GCN 17040;
Osborne et al. GCN 17043). At this time, we estimate a preliminary flux of about
142 uJy at 21.8 GHz. The map rms is about 9.3 uJy.
Further observations are ongoing.
GCN Circular 17063
Subject
GRB 141109A: TAROT La Silla observatory optical observations
Date
2014-11-12T23:17:57Z (11 years ago)
From
Alain Klotz at IRAP-CNRS-OMP <Alain.Klotz@free.fr>
Klotz A., Turpin D. (IRAP-CNRS-OMP),
Boer M., Gendre B., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:
We imaged the field of GRB 141109A detected by SWIFT
(trigger 618024) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.
The observations started 93s after the GRB trigger
(18s after the notice). The elevation of the field increased from
10 degrees above horizon and weather conditions were good.
The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
This image was obtained when the gamma emission was still
very active. We do not detect any OT with a limiting magnitude of:
t0+93s to t0+153s : Rlim = 12.9
The optical afterglow reported by Covino (GCNC 17039)
is detected in co added images (in tracking mode):
t0+465s to t0+655s : Rlim = 17.3
t0+665s to t0+868s : R = 16.8
t0+879s to t0+1069s : R = 16.1
t0+1093s to t0+1283s : R = 16.7
t0+1293s to t0+1497s : Rlim = 17.2
The TAROT photometry indicates that the optical afterglow
reached the maximum of light about 16 minutes after the
Swift trigger.
Magnitudes were estimated with the nearby NOMAD1 stars
and are not corrected for galactic dust extinction.
GCN Circular 17062
Subject
GRB 141109A: AAO optical observations
Date
2014-11-12T19:34:55Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), R. Inasaridze (AAO), A. Volnova (IKI), Molotov (KIAM),
A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 141109A (D'Avanzo et al., GCN
17037) with AS-32 (0.7m) telescope of Abastumani Observatory.
Observations were performed under mean seeing (FWHM) of 2.4". We
obtained several unfiltered images on Nov. 10 starting on (UT) 01:05:04.
At the position reported in (Covino, GCN 16932) we marginally
detected (S/N =2) the afterglow of GRB 141109A (Covino, GCN 16932; Xu
et al., GCN 17040; Graham et al., GCN 17041). Preliminary photometry is
following:
date UT start t-T0 Filter Exp. OT OT_err
(mid, days) (s)
2014-11-10 01:05:04 0.836 clear 37*120 21.7 0.4
The photometry is based on several SDSS-DR9 stars R magnitudes
transformed from SDSS-DR9 based on Lupton transformations:
SDSS-DR9 R
J093801.18-003731.5 17.6330
J093759.83-003741.8 17.2029
J093815.45-003332.9 18.2004
GCN Circular 17059
Subject
GRB 141109A: Terskol photometry
Date
2014-11-11T17:27:57Z (11 years ago)
From
Vladimir Sokolov at SAO RAS <sokolov@sao.ru>
I.V. Sokolov (TF INASAN, Russia), V.N. Komarova, A.S Moskvitin,
V.V. Sokolov, T.S.Sokolova (SAO RAS, Russia), report:
We observed the field of GRB 141109A (D'Avanzo et al., GCN 17037)
with the 2-meter telescope Zeiss-2000 (Terskol peak) on
November, 10, in 20.7 hours after the trigger.
10 x 300 sec. images in I filter were obtained.
The transient discovered by REM (Covino, GCN 17039) is clearly
detected in the stack frame. The OT magnitude is I = 21.1 +/- 0.1.
Photometry is based on the nearby SDSS stars. Their magnitudes
were converted with the transformation equations from Lupon, 2005.
GCN Circular 17057
Subject
GRB 141109A: Swift/UVOT Detection
Date
2014-11-10T22:55:16Z (11 years ago)
From
Frank Marshall at GSFC <femarsha@khamseen.gsfc.nasa.gov>
F.E. Marshall (NASA/GSFC) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 141109A
139 s after the BAT trigger (D'Avanzo et al., GCN Circ. 17037).
A source consistent with the optical position (Covino, GCN Circ. 17039;
Xu et al., GCN Circ. 17040) is detected in the initial UVOT exposures.
The preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 139 289 147 20.0 +/- 0.2
white 3991 4191 197 20.8 +/- 0.2
v 5656 5856 197 >18.9
b 3786 3986 197 >20.3
u 297 6276 227 >19.7
w1 6066 6266 197 >20.1
m2 5861 6061 197 >20.7
w2 4197 4339 140 >20.9
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 Circular 17056
Subject
GRB 141109A: NOT r-band observation
Date
2014-11-10T21:27:58Z (11 years ago)
From
Zach Cano at U of Iceland <zewcano@gmail.com>
���Z. Cano (U. Iceland), D. Malesani (DARK/NBI), K. Nilsson (FINCA), T.
Kangas (U. Turku), P. Jakobsson (U. Iceland) report on behalf of a larger
collaboration:
We observed the field of GRB 141109A (D'Avanzo et al., GCN Circ. 17037)
with the 2.5-m Nordic Optical Telescope (NOT) with ALFOSC starting at 04:39
UT on 10-Nov-2014. We obtained 3x300 s frames in the SDSS r-band filter.
We clearly detect the optical afterglow of GRB 141109A (Covino, GCN Circ.
17039; Xu et al., GCN Circ. 17040; Graham et al., GCN Circ. 17041; Im et
al., GCN Circ. 17042; Xin et al., GCN Circ. 17053), which has an apparent
magnitude of r=22.1 +- 0.1 at a mid exposure time of +22.8 hr. The
magnitude is not corrected for foreground extinction, and is calibrated
using several nearby SDSS stars in the FOV.���
GCN Circular 17055
Subject
Konus-Wind observation of GRB 141109A
Date
2014-11-10T17:35:48Z (11 years ago)
From
Valentin Pal'shin at Ioffe Inst <val@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, V. Pal'shin, D. Frederiks, P. Oleynik,
M.Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind
team report:
The most intense part of the long GRB 141109A (Swift-BAT trigger
#618024: D'Avanzo, et al., GCN Circ. 17037, Baumgartner, et al., GCN
Circ. 17044) was detected by Konus-Wind in the waiting mode.
The burst light curve shows two pulses started at ~T0(BAT)+31 s with a
total duration of ~94 s, and a weak tail seen in the soft energy range
G1 up to ~T0(BAT)+300 s.
As observed by Konus-Wind, the burst had a fluence of
1.37(-0.18,+0.20)x10^-5 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(BAT)+81 s, of (4.9 +/- 0.8)x10^-7 erg/cm2 (both in the
20 - 1200 keV energy range).
Modeling the K-W 3-channel time-integrated spectrum (from T0(BAT)+31 s
to T0(BAT)+125 s) by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.24(-0.25,+0.37), and Ep = 191(-43,+76) keV.
Assuming z = 2.993 (Xu et al., GCN 17040) and a standard cosmology model
with H_0 = 71 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73, the
isotropic energy release is E_iso = 3.31(-0.59,+0.78)x10^53 erg, and
the isotropic peak luminosity is L_iso = (4.8 +/- 0.9)x10^52 erg/s in 1
keV to 10 MeV at the GRB rest frame extrapolating the best exponential
cutoff function fit.
All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.
The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB141109A/
GCN Circular 17053
Subject
GRB141109A : Xinglong TNT optical observation
Date
2014-11-10T13:24:14Z (11 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L. P. Xin, X. F. Wang, J. Y. Wei, Y. L. Qiu, J. S. Deng,
J. Wang, X. H. Han and C. Wu on behalf of EAFON report:
We began to observe GRB 141109A (D'Avanzo et al., GCNC 17037)
with Xinglong 0.8-m TNT telescope at 2014-11-09, 19:45:06(UT),
about 13.95 hour after the burst.
The optical counterpart reported by ( Covino GCN 17039; Xu et al., 17040)
was detected in 24*300 sec R-band coadded image.
The brightness of the optical emission is estimated to be
about R=21.84 mag at the mid-time of 15.07 hours after the burst.
Combined with the reports ( Covino GCN 17039 and Xu et al., 17040 ),
the decay slope of this OT is roughtly about \alpha~1.12,
if we fit the data with a single power law.
The message may be cited.
GCN Circular 17049
Subject
GRB 141109A: MITSuME Ishigakijima upper limits
Date
2014-11-10T01:20:00Z (11 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ),
K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima),
K. Ohta (Kyoto) and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME and OISTER collaboration:
We observed the field of GRB 141109A (D'Avanzo et al., GCNC 17037)
with the optical three color (g', Rc and Ic) CCD camera attached
to the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.
The observation started on 2014-11-09 18:02:45.43 UT, (~12.2 h after the burst).
We could not detect the previously reported afterglow (Covino, GCNC 17039;
Xu et al., GCNC 17040; Graham et al., GCNC 17041) in all the three bands.
Three sigma upper limits of the OT are listed below.
We used SDSS catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' Rc Ic
-----------------------------------------------------
0.53718 18:43:28 3660.0 >20.9 >20.9 >20.1
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 17048
Subject
GRB 141109A: Swift-XRT refined Analysis
Date
2014-11-09T23:04:08Z (11 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf
of the Swift-XRT team:
We have analysed 5.7 ks of XRT data for GRB 141109A (D'Avanzo et al.
GCN Circ. 17037), from 119 s to 46.5 ks after the BAT trigger. The
data comprise 409 s in Windowed Timing (WT) mode (the first 8 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
Osborne et al. (GCN Circ. 17043).
The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=0.80 (+0.25, -0.14). At T+212 s the decay
steepens to an alpha of 3.25 (+0.51, -0.20) before breaking again at
T+363 s to a final decay with index alpha=1.254 (+0.021, -0.020). Some
flaring activity is observed between T+300 s and T+500 s.
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.673 (+0.028, -0.027). The
best-fitting absorption column is 1.73 (+0.11, -0.10) x 10^21 cm^-2,
in excess of the Galactic value of 3.3 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.99 (+0.14, -0.13)
and a best-fitting absorption column of 1.3 (+/-0.4) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.4 x 10^-11 (4.4 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: 3.3 x 10^20 cm^-2
Excess significance: 4.5 sigma
Photon index: 1.99 (+0.14, -0.13)
If the light curve continues to decay with a power-law decay index of
1.254, the count rate at T+24 hours will be 0.033 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-12 (1.4 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/00618024.
This circular is an official product of the Swift-XRT team.
GCN Circular 17044
Subject
GRB 141109A: Swift-BAT refined analysis
Date
2014-11-09T18:02:52Z (11 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
P. D'Avanzo (INAF-OAB), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 141109A (trigger #618024)
(D'Avanzo, et al., GCN Circ. 17037). The BAT ground-calculated position is
RA, Dec = 144.563, -0.581 deg, which is
RA(J2000) = 09h 38m 15.0s
Dec(J2000) = -00d 34' 52.4"
with an uncertainty of 3.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.
The mask-weighted light curve shows a weak peak from ~T+0 to ~T+40 sec,
then the bulk of the emission came from ~T+60 to ~T+190 sec, and then a tail
extending out to ~T+380 sec. T90 (15-350 keV) is 200 +- 47 sec
(estimated error including systematics).
The time-averaged spectrum from T+0.60 to T+323.15 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.52 +- 0.07. The fluence in the 15-150 keV band is 6.8 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+117.39 sec in the 15-150 keV band
is 2.5 +- 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/618024/BA/
GCN Circular 17043
Subject
GRB 141109A: Enhanced Swift-XRT position
Date
2014-11-09T14:35:35Z (11 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1173 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 141109A, 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 = 144.53083, -0.60795 which is equivalent
to:
RA (J2000): 09h 38m 7.40s
Dec (J2000): -00d 36' 28.6"
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 17042
Subject
GRB 141109A: CQUEAN Detection at 0.85 - 1.05 micron
Date
2014-11-09T14:01:05Z (11 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
Myungshin Im, Yongjung Kim, Minhee Hyun (CEOU/SNU),
Woojin Park, and Soojong Pak (Kyunghee Univ.)
We observed the field of GRB 141109A (D'Avanzo et al. GCN 17037),
using CQEUAN (Park et al. 2012) on the 2.1-m Otto-Struve telescope
at the McDonald Observatory in Texas, US. The observation started
at 2014-11-09 10:47:05 UT, or about 5 hrs after the BAT alert.
A series of images were taken with medium-band filters centered at
0.875, 0.925, 0.975, and 1.025 micron.
We identify the optical/NIR counterpart reported in Covino et al.
(GCN 17039), Xu et al. (GCN 17040), and Graham et al. (GCN 17041),
in all of the medium-band images. A preliminary magnitude
at 0.875 micron is 20.2 +- 0.1 AB mag. Further analysis of the data
is ongoing.
GCN Circular 17041
Subject
GRB 141109A: GROND afterglow observation
Date
2014-11-09T12:04:14Z (11 years ago)
From
Sebastian Schmidl at TLS Tautenburg <schmidl@tls-tautenburg.de>
J. Graham (MPE Garching), S. Schmidl (TLS Tautenburg), and J. Greiner (MPE
Garching) report on behalf of the GROND team:
We observed the field of GRB 141109A (Swift trigger 618024; P. D'Avanzo
et al., GCN 17037) simultaneously in g'r'i'z'JHK with GROND (Greiner et
al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La
Silla Observatory (Chile).
Observations started at 06:51 UT on November 09, 2014, approximately 1
hour after the GRB trigger. They were performed at an average seeing of
1.7" and at an average airmass of 1.6.
We detect the optical/NIR aftergow reported by Covino et al. (GCN 17039)
and Xu et al. (GCN 17040).
Based on total exposures of 25.0 minutes in g'r'i'z' and 20.0 minutes in
JHK, at a midtime of 2.3 hrs after the burst, we measure the following
preliminary magnitudes (AB magnitude system):
g' = 20.7 +/- 0.1 mag,
r' = 19.7 +/- 0.1 mag,
i' = 19.4 +/- 0.1 mag,
z' = 19.2 +/- 0.1 mag,
J = 19.0 +/- 0.1 mag,
H = 18.8 +/- 0.1 mag, and
K = 18.5 +/- 0.1 mag.
The magnitudes are calibrated against SDSS and 2MASS field stars and are
not corrected for the Galactic foreground extinction corresponding to a
reddening of E_(B-V)= 0.04 in the direction of the burst (Schlegel et al.
1998).
GCN Circular 17040
Subject
X-shooter redshift of GRB 141109A
Date
2014-11-09T10:43:29Z (11 years ago)
From
Paul Vreeswijk at Weizmann Inst of Science <paul.vreeswijk@weizmann.ac.il>
D. Xu (DARK/NBI), P. M. Vreeswijk (Weizmann), J. P. U. Fynbo
(DARK/NBI), V. D'Elia (ASI/ASDC and INAF/Roma), K. Wiersema,
N. R. Tanvir (Univ. Leicester), A. de Ugarte Postigo (IAA-CSIC),
S. Covino (INAF/OAB) report on behalf of a larger collaboration:
We observed the optical afterglow of the Swift GRB 141109A (D'Avanzo
et al., GCN 17037), using the X-shooter spectrograph at ESO's
VLT. Observations started at 07:45 UT on 2014 Nov 9 (1.9 hr after the
GRB), and consisted of 2x1200 s exposures in each of the UVB, VIS, and
NIR arms, covering the wavelength range 3000-20,000 AA.
In the acquisition image, we detect a point source, which is not
detected in the SDSS, at the position (J2000):
RA = 09:38:07.44
Dec = -00:36:29.9
with an uncertainty of about 0.5". This position is consistent with
that of the NIR afterglow reported by Covino et al. (GCN 17039). We
measure a (preliminary) magnitude of R=19.2+-0.1 (Vega).
We detect a variety of absorption features throughout the entire
spectrum. In particular, a wide trough is visible centered around 4800
AA, which we interpret as due to H I absorption at redshift z~3.
Identification of several metal features as due to, among others, Si
II, C II, Fe II, C IV, SiIV, allows us to refine the value to
z=2.993. The presence of several fine structure lines of Fe II, Si II,
O I, Ni II and C II confirms this is the redshift of the GRB.
We note the presence of two strong intervening system at z ~ 1.67 and
z ~ 2.5 (detected in Mg II).
We acknowledge excellent support from the ESO observing staff at
Paranal, in particular Valentin Ivanov and Marcelo Lopez. We also
thank the visiting astronomer Simone Zaglia from the ESO-GAIA survey,
who made these observation possible.
GCN Circular 17039
Subject
GRB 141109A: REM NIR candidate afterglow
Date
2014-11-09T09:56:07Z (11 years ago)
From
Stefano Covino at Brera Astronomical Observatory <stefano.covino@gmail.com>
S. Covino (INAF/OAB) on behalf of the REM team:
We observed the field of the GRB141109A (D'Avanzo et al., GCN 17037) simultaneously in the optical and near infrared with the the 60-cm robotic telescope REM at La Silla Observatory (Chile).
The observations started at 05:52:08 UT, about 2 min after the GRB, when the source was less than 10deg from the local horizon.
A candidate afterglow in the XRT error box is detected at the coordinates:
RA(J2000) = 09:38:07:40
DEC(J2000) = -00:36:30.13
A very preliminary photometry indicates it was H~15.7 about 35 min after the burst.
[GCN OPS NOTE(09nov14): Per author's request, "REM was added tot he Subject-line.]
GCN Circular 17037
Subject
GRB 141109A: Swift detection of a burst
Date
2014-11-09T06:05:41Z (11 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
P. D'Avanzo (INAF-OAB), S. D. Barthelmy (GSFC),
M. G. Bernardini (INAF-OAB), M. M. Chester (PSU),
A. Melandri (INAF-OAB), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Swift Team:
At 05:49:55 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 141109A (trigger=618024). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 144.507, -0.602, which is
RA(J2000) = 09h 38m 02s
Dec(J2000) = -00d 36' 04"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a multi-peak
structure with a duration of at least 170 sec. The peak count rate
was ~3000 counts/sec (15-350 keV), at ~118 sec after the trigger.
The XRT began observing the field at 05:52:04.3 UT, 129.2 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 144.5334, -0.6093 which is equivalent to:
RA(J2000) = +09h 38m 8.02s
Dec(J2000) = -00d 36' 33.5"
with an uncertainty of 6.5 arcseconds (radius, 90% containment). This
location is 98 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 0.1 s image was 1.18e-08 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 139 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 P. D'Avanzo (paolo.davanzo AT brera.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/too.html.)