GRB 130418A
GCN Circular 14537
Subject
GRB 130418A: TNG NIR observations
Date
2013-05-03T02:14:30Z (12 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, M. Cecconi, C. P. Padilla-Torres (INAF/TNG) report on behalf
of the CIBO collaboration:
We observed the field of GRB 130418A (De Pasquale et al., GCN 14377) with
the TNG telescope located in the Canary Islands. We obtained a set of
J-band images with the NICS camera on May 1.891 (mean observing time;
about 13.1 days from the GRB).
No source is detected at the optical afterglow position (De Pasquale et
al. GCN 14377; Gorosabel et al. GCN 14378; Quadri et al. 14379; Kuin et
al., GCN 14384; Hentunen et al., GCN 14394) down to a 3sigma limiting
magnitude of J~21.3 (calibrated against the 2MASS catalogue).
GCN Circular 14504
Subject
GRB 130418A: Bassano Bresciano Observatory lightcurve analisis
Date
2013-04-29T17:30:35Z (12 years ago)
From
Ulisse Quadri at Bassano Bresciano Obs <oabb@ulisse.bs.it>
U.Quadri, L.Strabla, R.Girelli and A.Quadri
report:
Photometric optical measurements of GRB 130418A detected by SWIFT trigger 553847
(de Pasquale et al. 2013; GCN Circ. 14377) have been done using the Schmidt
telescope 0.32m F/3.1 and Starlight CCD camera HX-516 applied at direct focus.
120 sec. exposure time and 2x2 binning were used for all photos.
All exposure were unfiltered.
Flat field and dark have been captured and all images were corrected with them.
Astrometrica software version 4.6.5.390 was used to perform differential photometry on
the reduced images.
began of period: 2013/04/18.80415 - 17 min after the burst.
end of period: 2013/04/18.92338 - 188 min after the burst.
The photometric results as follow:
------------------------------------
Date UTC Mag. 1 sigma.
------------------------------------
2013 04 18.80485 15.68 0.08
2013 04 18.80846 16.12 0.13
2013 04 18.82000 16.44 0.10
2013 04 18.90014 17.64 0.08
2013 04 18.85910 17.21 0.13
2013 04 18.87354 17.39 0.12
2013 04 18.88799 17.53 0.09
2013 04 18.90968 17.74 0.09
------------------------------------
Magnitudes were estimated with the USNO-B1 cat.
and are not corrected for galactic dust extinction.
Images and analisis are available at the following address:
http://www.osservatoriobassano.org/archivio/grb/GRB130418A-Trig-553847-2013-04-18.htm
This message may be cited.
GCN Circular 14438
Subject
GRB 130418A: Continued RATIR Optical and NIR Observations
Date
2013-04-22T21:17:15Z (12 years ago)
Edited On
2024-11-07T18:53:01Z (a year ago)
From
Nat Butler at Az State U <natbutler@asu.edu>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
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 (UCSC),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM),
Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)
report:
We observed the field of GRB 130418A (de Pasquale et al., GCN 14377) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional
on Sierra San Pedro Mártir from 2013/04 22.14 to 2013/04 22.33 UTC (80.35
to 84.95 hours after the BAT trigger), obtaining a total of 2.84 hours
exposure in the r' and i' bands and 1.19 hours exposure in the Z, Y, J, and
H bands.
At the position of the transient observed on 2013/04/19 (GCN 14388) and
2013/04/20 (GCN 14404), in comparison with SDSS DR8 and 2MASS, we obtain
the following upper limits (3-sigma) in the AB magnitude system:
r'> 23.12
i'> 22.93
Z > 22.52
Y > 21.89
J > 21.85
H > 21.25
These magnitudes are not corrected for Galactic extinction in the direction
of the GRB. The source is thus more than about 1 magnitude fainter than it
was observed to be two days ago.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
GCN Circular 14434
Subject
GRB 130418A: WSRT radio observation
Date
2013-04-22T06:50:13Z (12 years ago)
From
Alexander van der Horst at U of Amsterdam <A.J.vanderHorst@uva.nl>
A.J. van der Horst (University of Amsterdam) reports on behalf
of a large collaboration:
"We observed the position of the GRB 130418A afterglow at 4.9 GHz with
the Westerbork Synthesis Radio Telescope at April 21 13.53 UT to
April 22 01.49 UT, i.e. 2.77 - 3.27 days after the burst (GCN 14377).
We do not detect a radio source at the position of the optical
counterpart (GCN 14384). The three-sigma rms noise in the map around
that position is 69 microJy per beam. The formal flux measurement for
a point source at the position of the optical counterpart is 34 +/- 23
microJy.
We would like to thank the WSRT staff for quickly scheduling and
obtaining these observations."
GCN Circular 14417
Subject
Konus-Wind observation of GRB 130418A
Date
2013-04-20T17:42:33Z (12 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:
The long GRB 130418A (Swift-BAT trigger #553847:
De Pasquale et al., GCN 14377; Cummings et al., GCN 14392)
was observed by Konus-Wind (K-W) in the waiting mode.
K-W light curve shows a soft pulse started ~215 s before
the BAT trigger (T0(BAT)=19:00:53).
A total duration of the pulse is ~120 s.
The decay phase of the burst which had triggered Swift-BAT
is virtually indistinguishable from the K-W background.
Since the K-W ecliptic latitude response to the burst
is consistent with the BAT localization, we suggest
the pulse observed by K-W is an initial phase of GRB 130418A.
As observed by Konus-Wind, this part of the burst had
a fluence of (1.57 � 0.25)x10^-5 erg/cm2 and a 3-s peak flux,
measured from T0(BAT)-186 s, of (2.5 � 0.4)x10^-7 erg/cm2/s
(both in the 20 - 1200 keV energy range).
Fitting the K-W 3-channel time-averaged spectrum
(from T0(BAT)-215 s to T0(BAT)-95 s) by a simple
power-law model yields a photon index of 2.12 � 0.09,
which is consistent with the slope reported by BAT
for the burst tail.
Assuming z=1.218 (de Ugarte Postigo et al., GCN 14380;
Kruehler et al. GCN 14390) and a standard cosmology model
with H_0 = 70 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73,
the isotropic energy release E_iso is (6.3 � 1.0)x10^52 erg,
and the peak luminosity (L_iso)_max is (1.2 � 0.2)x10^51 erg/s.
All the quoted errors are estimated at the 1 sigma confidence level.
The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB130418A/
GCN Circular 14404
Subject
GRB 130418A: Continued RATIR Optical and NIR Observations
Date
2013-04-20T07:11:53Z (12 years ago)
Edited On
2024-11-07T19:51:35Z (a year ago)
From
Nat Butler at Az State U <natbutler@asu.edu>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
Subject: Subject: GRB 130418A: Continued RATIR Optical and NIR Observations
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 (UCSC),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM),
Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)
report:
We re-observed the field of GRB 130418A (De Pasquale, et al., GCN 14377)
with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico
Nacional on Sierra San Pedro Mártir from 2013/04 20.14 to 2013/04 20.26 UTC
(32.30 to 35.30 hours after the BAT trigger), obtaining a total of 2.13
hours exposure in the r' and i' bands and 0.89 hours exposure in the Z, Y,
J, and H bands.
Relative to our observations last night (GCN 14388), the GRB afterglow has
faded significantly, by approximately 3 magnitudes in all bands. In
comparison with SDSS DR8 and 2MASS, we find:
r' 21.74 +/- 0.12
i' 21.80 +/- 0.16
Z 21.52 +/- 0.26
Y 21.01 +/- 0.21
J 20.65 +/- 0.17
H 20.98 +/- 0.35
These magnitudes are in the AB system and not corrected for Galactic
extinction in the direction of the GRB. Uncertainties are 1-sigma.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
GCN Circular 14403
Subject
GRB 130418A: Swift-XRT refined Analysis
Date
2013-04-20T05:05:40Z (12 years ago)
From
Kim Page at U.of Leicester <klp5@leicester.ac.uk>
K.L. Page (U. Leicester) and M. De Pasquale (UCL-MSSL) report on behalf
of the Swift-XRT team:
We have analysed 2.7 ks of XRT data for GRB 130418A (De Pasquale et
al. GCN Circ. 14377), from 119 s to 15.6 ks after the BAT trigger.
The data comprise 262 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 Evans et al. (GCN. Circ 14383).
The light curve can be modelled with an initial power-law decay with an
index of alpha=0.72 (+/-0.11), followed by a break at T+801 s to an
alpha of 1.51 (+0.54, -0.30).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.24 (+/-0.06). The
best-fitting absorption column is 2.9 (+7.3, -2.9) x 10^20 cm^-2, at a
redshift of 1.218, in addition to the Galactic value of 2.7 x 10^20
cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index
of 1.70 (+0.24, -0.23) and a best-fitting absorption column of 2.6
(+3.0, -2.5) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10
keV flux conversion factor deduced from this spectrum is 4.2 x 10^-11
(4.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Galactic foreground: 2.7 x 10^20 cm^-2
Intrinsic column: 2.6 (+3.0, -2.5) x 10^21 cm^-2 at z=1.218
Photon index: 1.70 (+0.24, -0.23)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00553847.
This circular is an official product of the Swift-XRT team.
GCN Circular 14401
Subject
GRB 130418A: SMARTS optical/IR afterglow observations
Date
2013-04-19T22:41:06Z (12 years ago)
From
Bethany Cobb at GWU <bcobb@gwu.edu>
B. E. Cobb (GWU), reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained
optical/IR imaging of the error region of GRB 130418A (GCN 14377,
De Pasquale et al.) at two epochs (with mid-exposure times of
2013-04-19 00:03 UT & 01:24 UT). For each epoch, several dithered
images were obtained with total summed exposure times of
15 min in V and I and 12 min in J and K.
The fading afterglow of GRB 130418A (e.g. GCN 14377, De Pasquale
et al.; GCN 14378, Gorosabel et al.; GCN 14379, Quadri et al.)
was detected with the following magnitudes:
mid-exposure
time
(hours) V mag I mag J
mag K mag
5.03944 hours 18.41 +/- 0.03 17.57 +/- 0.03 16.46 +/- 0.10 14.82 +/-
0.10
6.38972 hours 18.59 +/- 0.03 17.69 +/- 0.03 16.70 +/- 0.10 15.05 +/-
0.10
(Optical photometry is calibrated against Landolt standard stars
and IR photometry is calibrated against a 2MASS star in the field.)
Between about 5 hrs and 6.4 hrs post-burst, the GRB afterglow fades with
a decay rate of approximately alpha = 0.6 +/- 0.2 in the optical
(where afterglow flux is proportional to t^-alpha).
GCN Circular 14400
Subject
GRB 130418A: Submm observations from SMA
Date
2013-04-19T22:04:32Z (12 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
S. Martin (ESO/ALMA), A. de Ugarte Postigo (IAA-CSIC) and G. Petitpas (SMA)
report on behalf of a larger collaboration:
We have observed the field of GRB 130418A (De Pasquale et al., GCN 14377) with
the Submillimeter Array (SMA) at Mauna Kea (Hawai, USA) in submm wavelengths.
Observations consisted of 1.25 hr on target with an average time 6.5 UT on 19
April 2013 (11.5 hr after the burst). We used 6 antennas on compact configuration,
under average weather conditions, with a precipitable water vapour of 2.5 mm or
an optical depth at 225 GHz of ~0.1. The central observing wavelength was
340 GHZ.
On a preliminary reduction we do not detect any source consistent with the
position of the GRB down to a 3-sigma limit of 14.5 mJy (r.m.s. 4.8mJy). This limit
is consistent with the 3 mm detection by CARMA (Perley, GCN 14387)
We acknowledge excellent support from the SMA staff.
GCN Circular 14395
Subject
GRB 130418A: T21 optical observation
Date
2013-04-19T16:59:36Z (12 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 130418A optical afterglow at iTelescope observatory
T21 (Mayhill, New Mexico) 0.43-m/6.8 astrograph and FLI ProLine PL6303E
CCD. One unfiltered image with 600 sec exposure time was made.
The afterglow was detected at following position RA 09:56:08.87 and DEC
+13:40:02.7.
The following magnitude was obtained from the image using NOMAD1
1036-0179295 (R = 14.910) as the comparison:
Tmid(h) +To Filter Exp.time Mag Mag err.
10.96 unfiltered 600 19.018 0.277
GCN Circular 14394
Subject
GRB 130418A: T18 and T21 optical observations
Date
2013-04-19T15:49:18Z (12 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 130418A optical afterglow at iTelescope observatories
T18 and T21. Four unfiltered and three photometric V filter images with 300 sec exposure time were made at T18 (AstroCamp Observatory, Nerpio, Spain) 0.32-m/8.0 Astorgraph and KAF-6303E CCD. Two unfiltered and four photometric V filter images with 600 sec exposure time were made at T21 (Mayhill, New Mexico) 0.43-m/6.8 astrograph and FLI ProLine PL6303E CCD.
The afterglow was detected at following position RA 09:56:08.94 and DEC +13:40:02.9.
The following magnitudes were obtained from the observations using
NOMAD1 1036-0179295 (V= 14.750, R = 14.910) as the comparison:
Tmid(sec) +T0 Filter Exp time Mag Mag err.
3119 unfiltered 300 16.200CR 0.026
3406 unfiltered 300 16.305CR 0.027
3758 unfiltered 300 16.381CR 0.027
4118 unfiltered 300 16.496CR 0.030
4835 V 300 16.895V 0.082
5195 V 300 16.979V 0.081
5546 V 300 16.983V 0.085
6432 V 600 17.320V 0.075
7093 V 600 17.342V 0.077
8026 unfiltered 600 17.328CR 0.044
8691 unfiltered 600 17.519CR 0.053
9742 V 600 17.775V 0.123
11059 V 600 17.752V 0.193
GCN Circular 14393
Subject
GRB 130418A: LOAO Observation
Date
2013-04-19T14:34:07Z (12 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
M. Im (CEOU/SNU), H.-I. Sung(KASI), and Y. Urata (NCU)
on behalf of EAFON
We observed the field of GRB 130418A (Pasquale et al., GCN 14377)
in R, I, and z filters using the 1-m telescope at Mt. Lemmon
observatory in Arizona, US.
The observation started at 2013-04-19 03:40 UT,
or about 8.6 hours after the BAT alert, and continued for
about 45 min. We clearly identify the fading afterglow in
R- and I-band, at the location reported earlier (Gorosabel et al.
GCN 14378; Quadri et al. GCN 14379; de Ugarte Postigo et al. GCN14380;
D'Avanzo et al. GCN 14381; Klotz et al. GCN14382; Kuin et al.
GCN14384; Tello et al. GCN 14385; Nardini et al. GCN 14386;
Perley et al. GCN 14387; Butler et al. GCN 14388; Covino et al.
GCN 14389; Kruehler et al. GCN 14390). On the other hand,
the detection in z-band is marginal.
Preliminary magnitudes of the afterglow, calibrated against
a USNO B-1 star at RA=140.047350 and Dec=+13.655828 are given below:
T(mid, UT) Mag
04-19 03:58:26 R=18.95 +- 0.07
04-19 04:04:16 I=18.18 +- 0.08
We thank the LOAO operator, Jae-Hyuk Yoon for performing
the observation.
GCN Circular 14392
Subject
GRB 130418A, Swift-BAT refined analysis
Date
2013-04-19T13:49:19Z (12 years ago)
From
Hans Krimm at NASA-GSFC <hans.krimm@nasa.gov>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), M. De Pasquale (UCL-MSSL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU),C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 130418A (trigger #553847)
(De Pasquale, et al., GCN Circ. 14377). The BAT ground-calculated position is
RA, Dec = 149.045, 13.674 deg which is
RA(J2000) = 09h 56m 10.8s
Dec(J2000) = +13d 40' 28.2"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 89%.
It appears that BAT triggered on the decay phase of a burst already in progress
when the source position came into the BAT field of view during a pre-planned
slew. Therefore we do not know the true time of the start of the burst, but it
was at least 50 seconds before T0, here defined as the trigger time. From T-50
sec, when the burst became visible, there is a steady decline punctuated by two
peaks at approximately T-20 and T+50, the first being harder than the second.
The decay continued to roughly T+300 sec. The burst location was no longer
visible after T+450, when another slew took it out of the BAT field. T90 cannot
be determined since BAT did not see the start of the burst, but T90 is at least
300 seconds.
The time-averaged spectrum from T-40.16 to T+285.59 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.07 +- 0.17. The fluence in the 15-150 keV band is 1.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-37.68 sec in the 15-150 keV band
is 0.6 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level. Note that these values are calculated only for the part of the burst
detected by the BAT, so the fluence should be considered a lower limit.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/553847/BA/
GCN Circular 14390
Subject
GRB130418A: VLT/X-shooter redshift confirmation
Date
2013-04-19T12:06:21Z (12 years ago)
From
Thomas Kruehler at Dark Cosmology Center <tom@dark-cosmology.dk>
T. Kruehler, D. Xu (both DARK), R. Sanchez-Ramirez (IAA-CSIC),
D. Malesani, J. Fynbo (both DARK) and H. Flores (GEPI/Obs. de Paris)
report on behalf of a larger collaboration:
We observed the optical/NIR counterpart (e.g., De Pasquale et al. GCN
14377, Gorosabel et al. GCN 14378) of GRB 130418A (De Pasquale et al.
GCN 14377) with the VLT/X-shooter spectrograph.
Our spectra cover the wavelength range 3000-25000 AA, and were taken
starting on 2013 Apr 18, 23:35:08 UT (4.57 hr after the GRB) for a
total exposure of 20 min.
We identify absorption lines of CIV, FeII and MgII at a common redshift
of z = 1.217 (see also de Ugarte Postigo et al., GCN 14380). The
doublet of CIV (1548, 1550) is also detected in a second absorption
system at z = 1.218. No emission lines are evident in our spectrum.
We thank the VLT staff, in particular Henri Boffin, Dimitri Gadotti and
Alex Correa, for the expert support in obtaining these data.
GCN Circular 14389
Subject
GRB 130418A: REM NIR observations
Date
2013-04-19T05:37:23Z (12 years ago)
From
Stefano Covino at Brera Astronomical Observatory <stefano.covino@gmail.com>
S. Covino, D. Fugazza, V. d'Elia, on behalf of the REM team report:
We imaged the field of GRB130418A (De Pasquale et al., GCN 14377) with
the
REM NIR camera equippe with the J, Hand Ks filters.
Observations started at 2013/04/18 23:12:37, i.e. about 4.2 hours after
the prompt event.
The optical counterpart detected by UVOT was well detected at
H=15.7+-0.1
(preliminary calibration) at the beginning of our observations.
GCN Circular 14388
Subject
GRB 130418A: RATIR Optical and NIR Observations
Date
2013-04-19T05:30:29Z (12 years ago)
Edited On
2024-11-07T19:40:42Z (a year ago)
From
Nat Butler at UC berkeley <natxbutler@gmail.com>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
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 (UCSC),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM),
Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)
report:
We observed the field of GRB 130418A (De Pasquale, et al., GCN 14377) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional
on Sierra San Pedro Mártir from 2013/04 19.14 to 2013/04 19.19 UTC (8.24 to
9.54 hours after the BAT trigger), obtaining a total of 1.07 hours exposure
in the r' and i' bands and 0.45 hours exposure in the Z, Y, J, and H bands.
For a source within the Swift-UVOT error circle (Kuin et al., GCN 14384),
in comparison with SDSS DR8 and 2MASS, we obtain the following detections
in the AB magnitude system:
r' 18.87 +/- 0.02
i' 18.77 +/- 0.02
Z 18.30 +/- 0.02
Y 18.07 +/- 0.02
J 18.06 +/- 0.02
H 17.53 +/- 0.02
These magnitudes are not corrected for Galactic extinction in the direction
of the GRB. Relative to the GROND detections about 3 hrs earlier (Nardini
et al., GCN 14386), the afterglow has faded by about 0.4 mag in all
optical/NIR bands. Continued observations are planned.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
GCN Circular 14387
Subject
GRB 130418A: CARMA 3mm detection
Date
2013-04-19T03:49:53Z (12 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 position of GRB 130418A (De Pasquale et al., GCN 14377)
with the Combined Array for Research in Millimeter Astronomy at a
frequency of 93 GHz (3mm) starting at 02:50 UT on 2013-04-19, 7.82 hours
after the burst. Observations continued until 03:26 UT (midpoint t=8.12
hours.)
A source is clearly detected at a position consistent with the location
of the UV, X-ray, and optical afterglow (De Pasquale et al., GCN 14377;
Gorosabel et al., GCN 14378; Quardri et al., GCN 14379). The
approximate flux at this time is ~3 mJy. Follow-up observations are
planned.
We thank the CARMA staff for their support in executing these observations.
GCN Circular 14386
Subject
GRB 130418A: GROND detection of the optical-NIR afterglow
Date
2013-04-19T02:58:43Z (12 years ago)
From
Mohit Tanga at MPE/GROND <mohit@mpe.mpg.de>
GRB 130418A: GROND detection of the optical-NIR afterglow
M. Nardini (UNIMIB), M. Tanga (MPE Garching), D. A. Kann (TLS Tautenburg)
and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field GRB 130418A (Swift trigger 553847; M. De Pasquale et
al., GCN 14377) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla
Observatory (Chile).
Observations started at 01:20:33 UT on April 19th, 6.3 hrs after the SWIFT
BAT trigger. They were performed at an average seeing of 1" and at an
average airmass of 1.38.
We detect the optical afterglow inside the 0.7" Swift/UVOT error circle
reported by De Pasquale et al., (GCN 14377) in all 7 bands. Based on the
first 4 min of total exposure we estimate preliminary magnitudes (all in
AB system) of
g' = 18.79 +- 0.03,
r' = 18.46 +-0.03,
i' = 18.22 +- 0.03,
z' = 17.95 +- 0.03,
J = 17.62 +- 0.05,
H = 17.17 +- 0.05 and
K = 16.81 +- 0.11
Given magnitudes are calibrated against SDSS as well as 2MASS field stars
and are not corrected for the expected Galactic foreground extinction
corresponding to a reddening of E_(B-V)=0.03 mag in the direction of the
burst (Schlegel et al. 1998).
GCN Circular 14385
Subject
GRB130418A: OSN 1.5m fading afterglow detection
Date
2013-04-19T02:32:19Z (12 years ago)
From
Juan Carlos Tello at IAA-CSIC <jtello@iaa.es>
J.C. Tello, R. Sanchez-Ramirez (IAA-CSIC), J. Gorosabel (IAA/CSIC-UPV/EHU),
F. Aceituno (OSN, IAA-CSIC) and A. Castro-Tirado (IAA-CSIC) on behalf of a
larger collaboration report:
We observed the field of GRB130418A reported by De Pasquale et al. (GCNC
14377) with the 1.5 meter telescope at the Sierra Nevada Observatory using
an I band filter, where we clearly detect a fading source coincident with
the UVOT afterglow position.
Preliminary results of an image taken at 21h20m (2.33h after the burst)
with a 300s exposure show the source presented a magnitude of I~17.13 when
compared to the USNO-B1.0 catalogue. Another image taken at 22h45m (3.74h
after the burst) with an exposure time of 60s shows a magnitude of I~17.51
(also preliminarily and when compared to the USNO-B1.0 catalogue).
More images were taken and will continue to be taken when the source rises
again above the local horizon.
GCN Circular 14384
Subject
GRB 130418A: Swift/UVOT Detection and request for continuing coverage
Date
2013-04-19T01:19:37Z (12 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin and M. De_Pasquale (UCL-MSSL) report on behalf of
the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 130418A
138 s after the BAT trigger (De_Pasquale et al., GCN Circ. 14377).
A source consistent with the XRT position (De Pasquale et al.
GCN Circ. 14377) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 09:56:08.88 = 149.03700 (deg.)
Dec (J2000) = +13:40:02.7 = 13.66741 (deg.)
with an estimated uncertainty of 0.50 arc sec. (radius, 90% confidence).
Preliminary detections 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 138 288 146 14.85 +/- 0.05
u 296 353 56 14.71 +/- 0.04
v 5634 5834 197 17.69 +/- 0.08
b 3567 3766 197 17.41 +/- 0.05
w1 6044 6124 78 17.25 +/- 0.11
m2 5839 6039 197 17.61 +/- 0.11
w2 5430 5630 197 18.08 +/- 0.11
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).
Due to a Moon constraint, Swift observations will stop for now. Continuing
acquisition of ground-based data, including ubv photometry will be useful
at this time.
GCN Circular 14383
Subject
GRB 130418A: Enhanced Swift-XRT position
Date
2013-04-19T00:45:26Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1098 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 130418A, 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 = 149.03689, +13.66721 which is equivalent
to:
RA (J2000): 09h 56m 8.85s
Dec (J2000): +13d 40' 02.0"
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 Circular 14382
Subject
GRB 130418A: TAROT Calern and TAROT la Silla observatory optical observations
Date
2013-04-19T00:34:28Z (12 years ago)
From
Alain Klotz at IRAP-CNRS-OMP <Alain.Klotz@free.fr>
Klotz A. (IRAP-CNRS-OMP), Gendre B. (IRAP-CNRS-OMP),
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:
We imaged the field of GRB 130418A detected by SWIFT
(trigger 553847) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.
Continuous observations started 78.7 min after the GRB trigger
due to the dusk. The elevation of the field
decreased from 58 degrees above horizon and weather conditions
were good. Four hours after the TAROT la Silla telescope
(Chile) started to observe.
The afterglow mentioned by De Pasquale (GCNC 14377)
appears clearly in the images.
The following magnitudes are obtained using the star
NOMAD-1 1036-0179295 (ra=149.0472378 dec=+13.6557094
R=14.91) for flux calibration:
Start Stop Rmag
(min) (min)
78.7 84.7 17.34
88.4 94.4 17.48
98.2 110.2 17.59
117.6 141.6 17.91
156.6 186.6 18.11
242.1 263.1 18.13
Considering a flux decay power law the corresponding
exponent is alpha=0.65.
Magnitudes are not corrected for galactic dust extinction.
This message may be cited.
GCN Circular 14381
Subject
GRB 130418A: TNG optical observations
Date
2013-04-18T23:45:34Z (12 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, A. Melandri (INAF/OAB), Avet Harutyunyan, G. Mainella
(INAF/TNG) report on behalf of the CIBO collaboration:
We observed the field of GRB 130418A (De Pasquale et al., GCN 14377) with
the TNG telescope located in the Canary Islands. We obtained a set of
images with the DOLORES camera in the B, V, R and I bands, starting on
2013 Apr 18 at 23:01:02 UT (4.0 hours after the GRB).
The optical afterglow (De Pasquale et al. GCN 14377; Gorosabel et al. GCN
14378; Quadri et al. 14379) is clearly detected in all bands. The measured
R-band magnitude is 18.1 (at t-t0=4.06 h; calibrated against the USNOB1
catalogue).
We acknowledge support from the TNG visiting astronomer F. Borsa.
GCN Circular 14380
Subject
GRB 130418A: Redshift from 10.4m GTC
Date
2013-04-18T22:49:12Z (12 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
J. Gorosabel (UPV/EHU, IAA-CSIC), R. Sanchez-Ramirez (IAA-CSIC),
J. P. U. Fynbo (DARK/NBI), N. Tanvir (U. Leicester) and
C.A. Alvarez Iglesias (IAC-ULL) report:
We have observed the afterglow of GRB 130418A (De Pasquale et al. GCN
14377) with the 10.4m GTC telescope starting at 21:45 UT (2.75 hr after the
burst). Observations consisted of 2x600s using the R1000B grating, with a
resolution of R~1000 in the range 3600 - 7900 A.
The spectrum shows a high S/N trace, with very weak MgII features at a
redshift of z = 1.218, which we identify as the redshift of the GRB.
[GCN OPS NOTE(19apr13): Per author's request, CAAI's affiliation
was changed from GTC to IAC-ULL.]
GCN Circular 14379
Subject
GRB 130418A: Bassano Bresciano Observatory optical observations
Date
2013-04-18T21:58:31Z (12 years ago)
From
Ulisse Quadri at Bassano Bresciano Obs <oabb@ulisse.bs.it>
U.Quadri, L.Strabla, R.Girelli and A.Quadri report:
We imaged the field of GRB 130418A (de Pasquale et al. 2013; GCN
Circ. 14377) detected by SWIFT(trigger 553847) with the robotic
telescope of (IAU station 565) Bassano Bresciano
Observatory, Italy.
The observations started 15 min. after the
GRB trigger,with our schmidt telescope
D=400 mm F/D=3.
Weather conditions were discrete for moon presence.
We co-added 14 unfiltered CCD exposures of 120s each.
We detect a new source of 16.3 Vmag in the error box given by SWIFT.
We detected the candidate couterpart at the following position (+/- 2 arcsec):
RA (J2000.0) = 09h 56m 08.90s
DEC(J2000.0) = +13�� 40' 02.8"
Magnitudes were estimated with the USNO-B1 cat.
and are not corrected for galactic dust extinction.
The message may be cited.
GCN Circular 14378
Subject
GRB 130418A: 1.23m I-band observations
Date
2013-04-18T20:53:45Z (12 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Gorosabel (IAA/CSIC-UPV/EHU), S. Perez-hoyos (UPV/EHU), I. Mendikoa
(UPV/EHU), A. Sanchez-Lavega (UPV/EHU), R. Hueso (UPV/EHU), J.F. Rojas
(UPV/EHU), A. de Ugarte Postigo (IAA/CSIC-DARK), report on behalf of a
larger collaboration:
We have observed the field of GRB130418A (de Pasquale et al. 2013; GCN
Circ. 14377) with 1.23m CAHA telescope equipped with PLANETCAM. The
observations started on 19:31 UT with the I-band filter. The optical
afterglow reported by de Pasquale et al. (GCN Circ. 14377) is well
detected with an approximate magnitue of I~15.6.
GCN Circular 14377
Subject
GRB 130418A: Swift detection of a burst with an optical counterpart
Date
2013-04-18T19:16:51Z (12 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
M. De Pasquale (UCL-MSSL), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), M. M. Chester (PSU),
S. T. Holland (STScI), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (UCL-MSSL),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
A. Maselli (INAF-IASFPA), P. T. O'Brien (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
B. Sbarufatti (INAF-OAB/PSU), E. Sonbas (NASA/GSFC/Adiyaman Univ.),
M. C. Stroh (PSU), C. A. Swenson (PSU) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift Team:
At 19:00:53 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130418A (trigger=553847). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 149.043, +13.649 which is
RA(J2000) = 09h 56m 10s
Dec(J2000) = +13d 38' 58"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). As is usual with image triggers, the BAT light
curve shows no significant features.
The XRT began observing the field at 19:03:03.2 UT, 129.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 149.0377, 13.6654 which is equivalent to:
RA(J2000) = +09h 56m 9.05s
Dec(J2000) = +13d 39' 55.4"
with an uncertainty of 5.3 arcseconds (radius, 90% containment). This
location is 61 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 138 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 09:56:08.92 = 149.03718
DEC(J2000) = +13:40:02.8 = 13.66744
with a 90%-confidence error radius of about 0.74 arc sec. This position is 7.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
14.96 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.03.
This source was detected on the first image trigger after it came
within the BAT's field of view, so its start time may be significantly
before the nominal trigger time. There is no significant fading
in the XRT over the ~300 second XRT observation time. Thus
it is likely that this is a very long duration event. The position
of the source is 47 degrees from the Galactic plane, but that
doesn't preclude a nearby source. Further determination of the
characteristics of the source will await further data analysis.
Burst Advocate for this burst is M. De Pasquale (m.depasquale AT ucl.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.)