GRB 140419A
GCN Circular 16281
Subject
GRB 140419A: Continued Mondy optical observations
Date
2014-05-16T15:49:12Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up
collaboration:
We continued observation of the Swift GRB 140419A (Marshall et al., GCN
16118) with AZT-33IK telescope of Sayan observatory (Mondy) on Apr.
25-26. We took several images in R-filter with the exposure of 60
seconds. On a stacked image from Apr. 25 we detect the optical afterglow
(Zheng et al., GCN 16119; Guver et al., GCN 16120; Butler et al., GCN
16121; Kuin et al., GCN 16123; Hentunen et al., GCN 16126). On the
stacked frame from Apr. 26 in the Swift/XRT error circle (Osborne et
al., GCN 16124) we do not detect any source.
Details of a photometry are the following:
date UT start t-T0 Filter Exp. OT
(mid, days) (s)
2014-04-25 14:48:25 6.47713 R 90*60 22.81+/-0.17
2014-04-26 14:21:55 7.45841 R 90*60 >21.7 (3 sigma)
The photometry is based on nearby SDSS star, R (gri -> R transformations
by Lupton 2005):
SDSS id R
J082752.69+461357.4 17.381+/-0.018
GCN Circular 16168
Subject
GRB 140419A: Continued Mondy optical observations
Date
2014-04-24T15:28:48Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up
collaboration:
We continued observation of the Swift GRB 140419A (Marshall et al., GCN
16118) with AZT-33IK telescope of Sayan observatory (Mondy) on Apr.
19-21. We took several images in R-filter. On a stacked image we clearly
detected the optical afterglow (Zheng et al., GCN 16119; Guver et al.,
GCN 16120; Butler et al., GCN 16121; Kuin et al., GCN 16123; Hentunen
et al., GCN 16126). Details of a photometry are the following:
date UT start t-T0 Filter Exp. OT
(mid, days) (s)
2014-04-22 14:49:26 3.45342 R 120*60 22.18 +/- 0.09
The photometry is based on nearby SDSS star, R (gri -> R transformations
by Lupton 2005):
SDSS id R
J082752.69+461357.4 17.381 �� 0.018
GCN Circular 16149
Subject
GRB 140419A, LOAO R-band observations
Date
2014-04-23T12:04:51Z (11 years ago)
From
Changsu Choi at Seoul Nat U <changsu@astro.snu.ac.kr>
Changsu Choi, Myungshin Im (CEOU/SNU), Hyun-Il Sung (KASI), and Yuji Urata
(NCU), on behalf of EAFON
We observed the field of GRB 140419A Swift GRB 140419A (Marshall et al., GCN
16118) in R-band using the 1-m telescope at Mt. Lemmon Optical Observatory
(LOAO) in Arizona, US
We obtained R-band images at two epochs on Apr. 19 and on Apr. 21.
We marginally identify the afterglow in a stacked image for each night.
The photometry is based on R1-mag of USNO-B1 stars in the observed field.
Details of Photometry are below:
date UT(mid time) Filter mag
2014/04/19 07:30:51 R 18.64 +/-0.29
2014/04/21 03:39:38 R 21.43 +/-0.27
We thank the LOAO operator, Jae-Hyuk Yoon for performing the observation.
GCN Circular 16141
Subject
GRB 140419A: Mondy optical observations
Date
2014-04-22T14:44:54Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up
collaboration:
We observed the field of the Swift GRB 140419A (Marshall et al., GCN
16118) with AZT-33IK telescope of Sayan observatory (Mondy) on Apr.
19-21. We took several images in R-filter of 60 s exposure. On stacked
images we clearly detected the optical afterglow (Zheng et al., GCN
16119; Guver et al., GCN 16120; Butler et al., GCN 16121; Kuin et al.,
GCN 16123; Hentunen et al., GCN 16126) except the combined image of
Apr. 19 due to unfavorable weather conditions. Our photometry is
consistent with the decaying law derived from RATIR observations
(Littlejohns et al., GCNs 16139, 16136).
The details of the photometry are the following:
date UT start t-T0 Filter Exp. OT Uplim
(mid, days) (s) 3sigma
2014-04-19 16:26:35 0.52030 R 10*60 n/d 19.3
2014-04-20 14:49:15 1.47495 R 83*60 21.12 +/- 0.10 21.6
2014-04-21 14:58:36 2.49015 R 107*60 21.60 +/- 0.15 22.2
The photometry is based on nearby SDSS star, R (gri -> R transformations
by Lupton 2005):
SDSS id R
J082752.69+461357.4 17.381 +/- 0.018
GCN Circular 16140
Subject
GRB 140419A: Refined NOT photometry
Date
2014-04-21T20:30:09Z (11 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu (DARK/NBI) reports:
The photometry of the NOT SDSS r-band data in GCN 16138 has been
refined. The detected object is not point-like but somewhat extended
in the NOT image. The photometry in GCN 16138 only covers a seemingly
bright part of the extended object. If the whole object is covered,
the brightness changes to m(R)=21.60+/-0.20 calibrated with the same
nearby SDSS stars, which now is consistent with the decaying law
derived from pre- and post-NOT observations (e.g., from RATIR; GCN
16139).
We thank Antonino Cucchiara for pointing out the difference in magnitudes.
GCN Circular 16139
Subject
GRB 140419A: Continued RATIR Optical and NIR Observations
Date
2014-04-21T19:19:13Z (11 years ago)
From
Owen Littlejohns at Az State U <olittlej@asu.edu>
Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC),
Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja
(GSFC), Enrico Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM), Leonid
Georgiev (UNAM), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM),
Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 140419A (Marshall, et al., GCN 16118) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional
on Sierra San Pedro M��rtir from 2014/04 21.14 to 2014/04 21.29 UTC (47.30
to 50.93 hours after the BAT trigger), obtaining a total of 2.49 hours
exposure in the r and i bands and 1.04 hours exposure in the Z, Y, J, and
H bands.
We continue to detect the UVOT optical transient (Zheng, et al., GCN 16116;
Guver et al., GCN 16120). For a source located at the position of the KAIT
optical counterpart candidate (Zheng, et al., GCN 16119), in comparison with
the SDSS DR9 and 2MASS, we obtain the following detections and upper limit
(3-sigma):
r 21.92 +/- 0.07
i 21.77 +/- 0.07
Z 21.74 +/- 0.13
Y 21.58 +/- 0.19
J 21.54 +/- 0.21
H > 21.66
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison to the first two
epochs of RATIR observations (Littlejohns, et al., GCN 16136; Butler, et
al., GCN 16121) we note that the decay in the NIR bands appears steeper,
now consistent with 1.4 < alpha < 1.6 in the i, Z, Y, J and H bands (see
also; Xu et al., GCN 16138). The XRT data for this GRB
(http://www.swift.ac.uk/xrt_curves/00596426/) may support a temporal break
at low significance after 100 ks. Further XRTdata can constrain this
possibility.
Conversely, the decay observed in the r band has become shallower, with
alpha = 0.8. This shallow decay in the r band could be attributed to the
presence of an underlying host galaxy or contamination from the nearby
bright star.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 16138
Subject
GRB140419A: NOT optical observations
Date
2014-04-21T17:59:57Z (11 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu (DARK/NBI), T. Kruehler (ESO), N. Tanvir (U. Leicester), F.
Taddia, C. Fremling (Stockholm U.) report on behalf of a larger
collaboration:
We observed the optical afterglow of GRB 140419A (Marshall et al., GCN
16118; Zheng et al., GCN 16119; Kuin et al., GCN 16123) using the 2.5
Nordic Optical Telescope equipped with ALFOSC. We obtained 4x300s,
3x300s, 4x200s frames in the SDSS g-, r-, and i-filters, respectively,
with floating clouds, starting at 23:10 UT on 2014-04-20 .
Photometry is calibrated with nearby SDSS stars, and results are as follows:
Tmid-T0(hr) Mag MagErr
43.24 >22.5
43.54 23.16 0.15
43.86 >20.3
Compared with previous measurements (e.g., from RATIR and KAIT), the
afterglow may be decaying more quickly.
GCN Circular 16137
Subject
GRB 140419A: KAIT Refined Analysis
Date
2014-04-21T05:21:29Z (11 years ago)
From
Weikang Zheng at UC Berkeley <zwk@astro.berkeley.edu>
WeiKang Zheng, Alexei V. Filippenko, Adam Morgan (UC Berkeley), and
S. B. Cenko (NASA/Goddard Space Flight Center) report on behalf of the
KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT) at
Lick Observatory responded to Swift GRB 140419A (Marshall et al.,
GCN 16118) starting at 04:10:00 UT, 189 s after the burst.
Observations were performed with an automatic sequence in the
V, I, and clear (roughly R) filters, and the exposure time was
20 s per image. The bright optical afterglow (Zheng et al.,
GCN 16119; Guver et al., GCN 16120) was well detected in
all three filters. Preliminary analysis shows that the afterglow
decays with a single power law (with alpha = -1.15) from the
beginning of our observations until about 3 hours later when the
position moved beyond our reach. The power-law index is consistent
with the value reported by Butler et al. (GCN 16121; GCN 16136).
We find (V - I) about 1.7 mag (no extinction correction), and no
obvious color change was detected during our observations. A
preliminary light curve is posted at
http://astro.berkeley.edu/~zwk/grb/GRB140419A/GRB140419A_kait.png
GCN Circular 16136
Subject
GRB 140419A: Continued RATIR Optical and NIR Observations
Date
2014-04-21T01:18:52Z (11 years ago)
From
Owen Littlejohns at Az State U <olittlej@asu.edu>
Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC),
Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja
(GSFC), Enrico Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM), Leonid
Georgiev (UNAM), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM),
Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 140419A (Marshall, et al., GCN 16118) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio Astron��mico
Nacional on Sierra San Pedro M��rtir from 2014/04 20.14 to 2014/04 20.29
UTC (23.23 to 26.83 hours after the BAT trigger), obtaining a total of
2.49 hours exposure in the r and i bands and 1.04 hours exposure in the Z,
Y, J, and H bands.
We continue to detect the UVOT optical transient (Zheng, et al., GCN 16116;
Guver et al., GCN 16120). For a source within the GCN-16119 error circle,
in comparison with the SDSS DR9 and 2MASS, we obtain the following
detections:
r 21.35 +/- 0.04
i 20.76 +/- 0.04
Z 20.61 +/- 0.06
Y 20.45 +/- 0.07
J 20.35 +/- 0.08
H 20.32 +/- 0.10
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison to the previous
epoch of RATIR observations (Butler, et al., GCN 16121) we find that the
source has continued to fade with an approximate power-law index of
alpha = 1.2 in all six bands.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 16134
Subject
Konus-Wind observation of GRB 140419A
Date
2014-04-20T15:07:10Z (11 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration, intense GRB 140419A
(Swift-BAT trigger #596426: Marshal et al., GCN 16118;
Baumgartner et al., GCN 16127)
triggered Konus-Wind at T0=14811.110 s UT (04:06:51.110).
The burst light curve shows a broad, hard-spectrum pulse
from ~T0-10 s to ~T0+40 s and a complex of narrow,
softer pulses around ~T0+50 s.
The total duration of the burst is ~80 s.
The emission is seen up to several MeV, however
the energy channels above ~2 MeV are strongly affected
by the high and variable solar particle background.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140419_T14811/
As observed by Konus-Wind, the burst
had a fluence of 5.8(-1.9,+2.8)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+7.744 s,
of 4.7(-1.9,+1.8)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum (measured from T0 to T0+76.032 s)
is best fit in the 20 keV - 1.9 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.63 (-0.22,+0.36),
the high energy photon index beta = -2.3 (-2.5,+0.4),
the peak energy Ep = 293 (-84,+84) keV,
chi2 = 51.1/59 dof.
The spectrum near the maximum count rate
(measured from T0+6.144 to T0+17.408 s)
is best fit in the 20 keV - 1.9 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.52 (-0.20,+0.24),
the high energy photon index beta = -2.3 (-2.7,+0.4),
the peak energy Ep = 363 (-75,+96) keV,
chi2 = 70.7/60 dof.
Assuming the redshift z=3.956 (Tanvir et al., GCN 15645)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~1.9x10^54 erg,
the peak luminosity L_iso is ~7.5x10^53 erg/s,
and the rest-frame peak energy Ep,i is ~1450 keV.
These estimates place GRB 140419A among the most
energetic GRBs.
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 16133
Subject
GRB 140419A, Optical Observations
Date
2014-04-20T14:50:33Z (11 years ago)
From
Shashi Bhushan Pandey at ROTSE <shaship@umich.edu>
S. B. Pandey and Brajesh Kumar (ARIES Nainital India, on behalf of larger
Indian GRB collaboration)
We observed the Swift GRB 140419A field (Marshall et al., GCN 16118) using
1.04m ST telescope at ARIES Nainital. Observations were started at 14:44:38
UT on 2014-04-19 (approximately 10.6 h after the burst). Several frames
with an exposure time of 300 s each in R_c band were obtained in good sky
conditions.
The optical counterpart of GRB 140419A (Zheng et al., GCN 16119; Guver et
al., GCN 16120; Butler et al.,GCN 16121; Kuin et al., GCN 16123; Hentunen
et al., GCN 16126; Cenko et al., GCN 16129) is clearly detected in each
individual frames. The preliminary photometry of the first frame is 19.8 +-
0.1 mag. The photometry was performed in comparison to nearby USNO stars.
This massage may be cited.
GCN Circular 16132
Subject
GRB 140419A: MITSuME Ishigakijima Optical Observation
Date
2014-04-20T10:22:25Z (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 collaboration:
We observed the field of GRB 140419A (Marshall et al., GCNC 16118)
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 2014-04-19 12:40:26 UT (~8.6 h after the burst).
We detected the previously reported afterglow (Marshall et al., GCNC 16118;
Zheng et al., GCNC 16119) in all the three bands.
Photometric results of the OT are listed below.
We used SDSS catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err
----------------------------------------------------------------------
0.39781 13:39:41 5820.0 20.6 0.1 19.5 0.1 19.1 0.1
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 16131
Subject
GRB 140419A: MITSuME Okayama Optical Observation
Date
2014-04-20T07:34:30Z (11 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 the MITSuME collaboration:
We observed the field of GRB 140419A (Marshall et al., GCNC 16118)
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 2014-04-19 11:17:09 UT (~7.2 h after the burst).
We detected the previously reported afterglow (Marshall et al., GCNC 16118;
Zheng et al., GCNC 16119) in Rc and Ic bands.
Three sigma upper limit and photometric results of the OT are listed below.
We used SDSS catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' Rc Rc_err Ic Ic_err
-----------------------------------------------------------------------
0.36126 12:47:03 8700.0 >20.1 19.8 0.3 19.1 0.3
------------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 16130
Subject
GRB 140419A: Swift UVOT refined analysis
Date
2014-04-19T21:55:33Z (11 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and F. E. Marshall (NASA/GSFC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 140419A
97 s after the BAT trigger (Marshall et al. GCN Circ. 16118).
Optical and IR photometry and positions were reported, as well as a redshift
(Cenko, et al., GCN Circ. 16129; Hentunen et al., GCN Circ. 16126; Tanvir
et
al., GCN Circ. 16125; Kuin et al., GCN Circ. 16123; Butler et al., GCN
Circ.
16121; Guver et al., GCN Circ. 16120; and Zheng et al., GCN Circ. 16119.)
A source consistent with the XRT position is detected in the initial UVOT
exposures.
The preliminary UVOT position is:
RA (J2000) = 08:27:57.56 = 126.98982 (deg.)
Dec (J2000) = +46:14:25.3 = 46.24037 (deg.)
with an estimated uncertainty of 0.50 arc sec. (radius, 90% confidence).
Due to the GRB lying on the edge of a large scattered light feature from
the
bright star nearby, photometry errors are large until a good background
template can be made at late times.
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 97 246 147 16.2 +/- 0.2
v 638 658 19 16.1 +/- 0.2
b 564 756 39 18.4 +/- 0.2
u 309 2003 362 >21.0
w1 687 707 19 >18.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 16129
Subject
GRB 140419A: P60 Observations
Date
2014-04-19T20:26:32Z (11 years ago)
From
S. Bradley Cenko at NASA/GSFC <brad.cenko@nasa.gov>
S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report on behalf of a larger collaboration:
We observed the optical afterglow (Zheng et al., GCN 16119; Guver et al., GCN 16120; Butler et al., GCN 16121; Kuin et al., GCN 16123; Hentunen et al., GCN 16126) of the Swift GRB 140419A (Marshall et al., GCN 16118) with the robotic Palomar 60 inch telescope. Observations were obtained in the r', i', and z' filters beginning at 4:40 UT on 2014 April 19 (33 minutes after the Swift trigger).
The optical afterglow is clearly detected in all three filters. Using nearby point sources from SDSS for calibration, we measure the following magnitudes in our initial images:
r' = 16.91 +/- 0.03 at dt = 33.7 min
i' = 16.56 +/- 0.03 at dt = 35.1 min
z' = 16.45 +/- 0.04 at dt = 36.5 min
The redder r'-i' color is consistent with the Lyman break falling in the observed r' bandpass, as reported by Tanvir et al. (GCN 16125).
Further observations are planned.
GCN Circular 16128
Subject
GRB 140419A: Swift-XRT refined Analysis
Date
2014-04-19T17:31:39Z (11 years ago)
From
Alessandro Maselli at INAF/IASF Palermo <maselli@ifc.inaf.it>
A. Maselli, M. De Pasquale (INAF-IASFPA), P. A. Evans (U Leicester) and
F. E. Marshall (NASA/GSFC) report on behalf of the Swift-XRT team:
We have analysed 10 ks of XRT data for GRB 140419A (Marshall et al. GCN
Circ. 16118), from 79 s to 24.3 ks after the BAT trigger. The data
comprise 849 s in Windowed Timing (WT) mode (the first 5 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. 16124).
The late-time light curve (from T0+5.4 ks) can be modelled with a
power-law decay with a decay index of alpha=1.29 (+/-0.07).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.803 (+0.029, -0.028). The
best-fitting absorption column is 1.7 (+2.8, -1.7) x 10^21 cm^-2, at a
redshift of 3.956, in addition to the Galactic value of 3.9 x 10^20
cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index
of 1.83 (+/-0.06) and a best-fitting absorption column of 1.2 (+/-0.6)
x 10^22 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum is 3.6 x 10^-11 (4.0 x
10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Galactic foreground: 3.9 x 10^20 cm^-2
Intrinsic column: 1.2 (+/-0.6) x 10^22 cm^-2 at z=3.956
Photon index: 1.83 (+/-0.06)
If the light curve continues to decay with a power-law decay index of
1.29, the count rate at T+24 hours will be 0.042 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.5 x
10^-12 (1.7 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/00596426.
This circular is an official product of the Swift-XRT team.
GCN Circular 16127
Subject
GRB 140419A: Swift-BAT refined analysis
Date
2014-04-19T15:19:34Z (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),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC),
C. B. Markwardt (GSFC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+485 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 140419A (trigger #596426)
(Marshall, et al., GCN Circ. 16118). The BAT ground-calculated position is
RA, Dec = 127.001, 46.234 deg, which is
RA(J2000) = 08h 28m 00.4s
Dec(J2000) = +46d 14' 03.7"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 33%.
The mask-weighted light curve shows two slightly overlapping clusters of
peaks, starting at ~T-10 sec, peaking at ~T+10 and ~T+51 sec, and ending
at ~T+220 sec. T90 (15-350 keV) is 94.7 +- 11.0 sec (estimated error
including systematics).
The time-averaged spectrum from T-8.69 to T+222.32 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.21 +- 0.04. The fluence in the 15-150 keV band is 1.59 +- 0.03 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+51.42 sec in the 15-150 keV band
is 4.9 +- 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/596426/BA/
[GCN OPS NOTE(22apr14): Per author's request, the fluence value
was changed from "1.6 +- 0.0" to "1.59 +- 0.03". Acknowledgement
to F.Marshall for pointing out the missing error value.]
GCN Circular 16126
Subject
GRB 140419A: T24 optical observations
Date
2014-04-19T13:23:00Z (11 years ago)
From
Veli-Pekka Hentunen at Taurus Hill Obs,A95 <veli-pekka.hentunen@kassiopeia.net>
Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill
Observatory, Varkaus, Finland) report:
We have detected GRB 140419A optical afterglow at iTelescope observatory
T24 (Auberry, California) using 0.61-m/6.5 astrograph and FLI-PL09000 CCD.
The observations were started at 2014-04-19 06:34:54 (UT) and stopped at
06:56:31 (UT). Four unfiltered images with 300 sec exposure time were made.
The afterglow was detected at the following position RA 08:27:57.56 and
DEC +46:14:25.2.
The following magnitude was obtained from the observations using
NOMAD1 1362-0196617 (R=17.110) as a comparison star:
Tmid(s)+T0 Filter Exp. time Mag Mag err.
9536 unfiltered 4x300s 17.86CR 0.12
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GCN Circular 16125
Subject
GRB 140419A: Gemini-N redshift
Date
2014-04-19T13:21:37Z (11 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick),
A. Cucchiarra (ORAU/GSFC), D. Perley (Caltech), S. B. Cenko (GSFC)
D. Coulson, L. Fuhrman report:
We observed the afterglow of GRB 140419A (Marshall et al. GCN 16118;
Zheng et al. GCN 16119; Guver et al. GCN 16120; Butler et al. GCN 16121)
with the GMOS-N spectrograph on Gemini-N. Observations began
at 06:24 UT, approximately 2.3 hr post burst, and two different
settings covered a total wavelength range from about 4400AA to 10100AA.
The spectra reveal several strong absorption lines and in particular
there is a marked break at about 6027 AA which we identify as
Ly-a at a redshift z=3.956. Blueward is a clear Ly-a forest.
At the same redshift we see strong lines of CIV (1548/1551) and
SiIV (1394/1403), and weaker lines of NV (1239/1243), CII (1335),
SiII (1527), AlII (1671). We therefore infer z=3.956 as the redshift of
the burst.
We note that there also appears to be an intervening system at z=2.686.
[GCN OPS NOTE(19apr14): Per author's request, DC and LF were added
to the author list.]
GCN Circular 16124
Subject
GRB 140419A: Enhanced Swift-XRT position
Date
2014-04-19T11:56:14Z (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 3698 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 140419A, 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 = 126.98969, +46.24009 which is equivalent
to:
RA (J2000): 08h 27m 57.53s
Dec (J2000): +46d 14' 24.3"
with an uncertainty of 1.5 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 16123
Subject
GRB140419A: UVOT detects fading afterglow in white but not in u filter
Date
2014-04-19T07:56:22Z (11 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
NPM Kuin (MSSL-UCL), and F. E. Marshall (NASA/GSFC) report on behalf of
the Swift Team:
UVOT started observing GRB 140419A starting 96 seconds after the BAT
trigger.
The initial finding chart exposures with the White and U filter show a
fading source in the white filter which we identify with the afterglow:
The estimated magnitudes are as follows:
filter starttime endtime magnitude error
wh 96 246 16.01 0.06
u 308 558 >19.6
wh 862 1012 17.96 0.09.
The source is not seen in the u filter, which suggests a redshift larger
then
2.8.
No correction has been made for the expected extinction corresponding to
E(B-V) of 0.03.
GCN Circular 16122
Subject
GRB 140419A: CARMA early 3mm detection
Date
2014-04-19T07:07:57Z (11 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech) reports on behalf of a larger collaboration:
We observed the location of GRB 140419A (Marshall et al., GCN 16118)
with the Combined Array for Research in Millimeter Astronomy at a mean
frequency of 93 GHz starting at 05:23:45, 77 minutes after the GRB
trigger.
In the first hour of observations, we marginally detect a weak source
consistent with the location of the optical afterglow (Zheng et al., GCN
16119; Guver et al., GCN 16120) with a flux of approximately 1.5 mJy.
Observations are continuing.
We thank J. Carpenter and D. Segura-Cox for assistance with rapidly
scheduling and executing the observations.
GCN Circular 16121
Subject
GRB 140419A: RATIR Optical and NIR Observations
Date
2014-04-19T05:30:28Z (11 years ago)
From
Nat Butler at Az State U <natbutler@asu.edu>
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes��s
Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC), and
Harvey Moseley (GSFC) report:
We observed the field of GRB 140419A (Marshall, et al., GCN 16118) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional on
Sierra San Pedro M��rtir from 2014/04 19.18 to 2014/04 19.20 UTC (9 to 40
minutes after the BAT trigger), obtaining a total of 0.36 hours exposure in
the r and i bands and 0.15 hours exposure in the Z, Y, J, and H bands.
We detect the UVOT optical transient (see also, Zheng, et al., GCN 16116;
Guver et al., GCN 16120). In comparison with the SDSS DR9 and 2MASS, we
obtain the following detections:
r 16.22 +/- 0.01
i 15.81 +/- 0.01
Z 15.66 +/- 0.01
Y 15.46 +/- 0.02
J 15.31 +/- 0.01
H 15.26 +/- 0.02
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. The source appears to be fading
approximately as t^(-1) in all of our bands during the observation.
Further observations are ongoing. We thank the staff of the Observatorio
Astron��mico Nacional in San Pedro M��rtir.
GCN Circular 16120
Subject
GRB 140419A: ROTSE-III Detection of Optical Counterpart
Date
2014-04-19T04:40:43Z (11 years ago)
From
Tolga Guver at UA <tolga@physics.arizona.edu>
GRB 140419A: ROTSE-III Detection of Optical Counterpart
T. Guver (Istanbul Univ.), F. V. Ferrante (SMU), H. Flewelling
(IfA/Hawaii), R. Kehoe (SMU), G. Dhungana (SMU) report on behalf of
the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
140419A (Swift trigger 596426, GCN 16118). The first image was at
04:07:18.7 UT, 27.3 s after the burst (8.7 s after the GCN notice
time). The unfiltered images are calibrated relative to USNO A2.0. We
detect a new object, not visible in the DSS (second epoch), with
coordinates:
08:27:57.7 +46:14:25.9 (J2000), with positional uncertainty of 1' or better
start UT mag mlim(of image)
----------------------------------
04:07:18.7 13.5 15.0
The object first detected with a magnitude of ~13.5, brightened to
12.5 magnitudes in ~70 seconds then the brightness decayed fast to
~14.3 magnitudes at about 350 seconds.
A jpeg image is available at
http://www.rotse.net/images/gsq596426_3b01_img.jpg Note that the
object marked 8 is the candidate in question.
Continuing observations are in progress.
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GCN Circular 16119
Subject
GRB 140419A (Swift trigger 596426) : KAIT optical candidate
Date
2014-04-19T04:29:15Z (11 years ago)
From
Weikang Zheng at UC Berkeley <zwk@astro.berkeley.edu>
WeiKang Zheng, Alexei V. Filippenko, Adam Morgan (UC Berkeley), and
S. B. Cenko (NASA/Goddard Space Flight Center) report on behalf of the
KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift trigger 596426. A bright
(R~13.5) optical counterpart un-cataloged in DSS image was detected
at location of Ra, DEC (J2000):
08:27:57.56
+46:14:25.11
with uncertainty of about 1". We suggest this to be the afterglow of
the GRB. Follow-up observations encouraged.
GCN Circular 16118
Subject
GRB 140419A: Swift detection of a burst with optical afterglow
Date
2014-04-19T04:21:34Z (11 years ago)
From
Caryl Gronwall at PSU/Swift-UVOT <caryl@astro.psu.edu>
F. E. Marshall (NASA/GSFC), J. R. Cummings (NASA/UMBC),
C. Gronwall (PSU), J. A. Kennea (PSU), A. Maselli (INAF-IASFPA),
T. Sakamoto (AGU), M. H. Siegel (PSU) and T. N. Ukwatta (MSU) report
on behalf of the Swift Team:
At 04:06:51 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140419A (trigger=596426). Swift slewed immediately to the
burst. The BAT on-board calculated location is
RA, Dec 126.999, +46.221 which is
RA(J2000) = 08h 28m 00s
Dec(J2000) = +46d 13' 15"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multi-peaked
structure with a duration of about 80 sec. The peak count rate
was ~5611 counts/sec (15-350 keV), at ~52 sec after the trigger.
The XRT began observing the field at 04:08:17.5 UT, 86.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 126.9909, 46.2416 which is equivalent to:
RA(J2000) = +08h 27m 57.82s
Dec(J2000) = +46d 14' 29.8"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 76 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 5.09e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White
filter starting 96 seconds after the BAT trigger. A bright
uncatalogued source is identified in the 2.7'x2.7' sub-image near the
position of the XRT afterglow. However, a more precise position is
unavailable at this time. The approximate magnitude in the White
filter is 16.1. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.03.
Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov).
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.)