GRB 150428A
GCN Circular 30324
Subject
GRB 150428A: late-time radio observations
Date
2021-06-26T13:58:18Z (4 years ago)
From
James Leung at U of Sydney/VAST <jleu9465@uni.sydney.edu.au>
James Leung (University of Sydney/CSIRO), Poonam Chandra (NCRA-TIFR),
Emil Lenc (CSIRO), Tara Murphy (University of Sydney), Ziteng Wang
(University of Sydney/CSIRO)
ASKAP J123409+065712 is a radio source found in a search of
Australian Square Kilometre Array Pathfinder (ASKAP) data (SB10736).
The radio source position is consistent with the enhanced Swift-XRT
position (Osborne et al., GCN Circ. 17768) and inconsistent with the
GROND source position (Knust et al., GCN Circ. 17767).
We conducted further observations of the radio source with the
Australia Telescope Compact Array (ATCA) and the upgraded Giant
Metrewave Radio Telescope (uGMRT). We summarise these observations in
the table below.
Date (UTC) | Telescope | Freq (GHz) | Peak Flux Density (uJy/beam)
------------------------------------------------------------------
2019/12/05 | ASKAP | 1.4 | 363 +/- 56
2021/05/21 | ATCA | 5.5 | 94 +/- 26
2021/06/13 | uGMRT | 1.3 | 386 +/- 17
The fitted position of the radio source from the uGMRT observation is
RA: 12:34:09.296
Dec: +06:57:13.83
Observations of the radio source do not show any evidence for fading
in epochs separated by 555 days and we therefore conclude the source
is likely the host galaxy of GRB 150428A.
We thank CSIRO and GMRT staff for supporting these observations
during these especially difficult times.
GCN Circular 17802
Subject
Konus-Wind observation of GRB 150428A
Date
2015-05-04T14:55:51Z (11 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 150428A (Swift-BAT trigger #639275:
Page, et al., GCN Circ. 17765; Baumgartner, et al., GCN Circ. 17774)
was detected by Konus-Wind in the waiting mode.
The burst light curve shows a single pulse which started approximately
at BAT trigger time T0(BAT) and has a duration of ~45 s.
As observed by Konus-Wind, the burst had a fluence of
1.61(-0.09,+0.10)x10^-5 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(BAT)+21 s, of 5.5(-0.7,+0.9)x10^-7 erg/cm2
(both in the 20 - 1200 keV energy range).
Modelling the K-W 3-channel time-integrated spectrum (from T0(BAT)-3 s
to T0(BAT)+41 s) by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.04(-0.12,+0.14), and Ep = 275(-29,+37) keV.
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/GRB150428A/
GCN Circular 17785
Subject
GRB 150428A: Swift/UVOT Upper Limits
Date
2015-04-29T00:43:45Z (11 years ago)
From
Margaret Chester at PSU <chester@swift.psu.edu>
M. M. Chester (PSU) and K. L. Page (U Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150428A
179 s after the BAT trigger (Page et al., GCN Circ. 17765). No optical
afterglow consistent with the enhanced XRT position (Osborne et al. GCN
Circ. 17768) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and one subsequent exposure are:
Filter T_start(s) T_stop(s) Exp(s) UL (3-sigma)
white_FC 179 329 147 >20.9
u 3572 3726 152 >19.9
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 17778
Subject
GRB 150428A: MASTER-net early optical observation
Date
2015-04-28T15:19:00Z (11 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory
E. Gorbovskoy, V. Lipunov, N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov,
D.Kuvshinov,
Lomonosov Moscow State University, Sternberg Astronomical Institute
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk
V.Krushinski, I.Zalozhnih, A. Popov
Ural Federal University, Kourovka
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in SAAO was pointed to the GRB150428A (Page et al, GCN 17765) 28
sec after notice time and 90 sec after trigger time at 2015-04-28 01:32:10
UT in two polarizations. On our first single and coadd images we haven`t
found optical transient within SWIFT error-box . The observations made on
a high zenith distance ~ 80 d.
We obtain a followin upper limits:
Date start T_s-T_tr T_m-T_trig Expt. Limit Coadd
(mean_time)
01:32:10.9 90 100 20 16.0 no
01:32:43.2 122 132 20 16.0 no
01:33:14.7 153 168 30 16.4 no
01:33:14.7 153 224 120 17.0 3
01:33:14.7 153 583 770 18.5 9
Also, we can not confirm Danish 1.56m OT (Andersen et. al GCN 17771),
because they do not see it on our images with upper limits specified
above.
The message may be cited.
GCN Circular 17777
Subject
GRB 150428A: Swift-XRT refined Analysis
Date
2015-04-28T14:13:12Z (11 years ago)
From
Kim Page at U.of Leicester <kpa@star.le.ac.uk>
K. L. Page (U Leicester) reports on behalf of the Swift-XRT team:
We have analysed 1.3 ks of XRT data for GRB 150428A (Page et al. GCN
Circ. 17765), from 160 s to 32.5 ks after the BAT trigger. The data
comprise 8 s in Windowed Timing (WT) mode (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.
17768).
The light curve can be modelled with a power-law decay with a decay
index of alpha=0.75 (+/-0.05).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.0 (+0.4, -0.3). The
best-fitting absorption column is 5.3 (+2.4, -1.9) x 10^21 cm^-2, in
excess of the Galactic value of 1.6 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 4.1 x 10^-11 (6.8 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 5.3 (+2.4, -1.9) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^20 cm^-2
Excess significance: 4.4 sigma
Photon index: 2.0 (+0.4, -0.3)
If the light curve continues to decay with a power-law decay index of
0.75, the count rate at T+24 hours will be 0.028 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-12 (1.9 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/00639275.
This circular is an official product of the Swift-XRT team.
GCN Circular 17774
Subject
GRB 150428A: Swift-BAT refined analysis
Date
2015-04-28T12:49:41Z (11 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
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 (GSFC/UMBC),
C. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 150428A (trigger #639275)
(Page, et al., GCN Circ. 17765). The BAT ground-calculated position is
RA, Dec = 188.539, 6.967 deg which is
RA(J2000) = 12h 34m 09.3s
Dec(J2000) = +06d 58' 00.8���
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 16%.
The mask-weighted light curve shows a multi-peaked structure that starts at
~ T-40 sec and ends at ~ T+60 sec. T90 (15-350 keV) is 53.2 +- 15.1 sec
(estimated error including systematics).
The time-averaged spectrum from T-39.0 to T+38.6 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is 1.28 +- 0.09.
The fluence in the 15-150 keV band is 6.3 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak
photon flux measured from T+17.4 sec in the 15-150 keV band is 3.0 +- 0.5 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/639275/BA/
GCN Circular 17771
Subject
GRB 150428A: Danish1.56m optical observations
Date
2015-04-28T07:29:12Z (11 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
M. I. Andersen (NBI/StarPlan), D. Xu (NAOC/CAS), M. Kuffmeier (StarPlan), and D. Evans (Keele U.) report on behalf of a larger collaboration:
We observed the field of GRB 150428A (Page et al., GCN 17765) using the Danish 1.56m telescope located at La Silla, Chile. Observations started at 01:56:33 UT on 2015-04-28 (i.e., 0.43 hr post-burst) and 12x180s R-band images were obtained.
We marginally detect a source in the stacked image at coordinates
R.A. = 12:34:09.227
Dec. = +6:57:14.07
Error Radius: ~ 1 arcsec,
consistent with the enhanced XRT position (Osborne et al., GCN 17768). Preliminary reduction shows that the source has m(R) = 22.50 +/- 0.43 mag at a median time of 0.887 hr post-burst, calibrated with two nearby SDSS stars. It could be the afterglow of the GRB.
We also detect the source reported by GROND (Knust et al., GCN 17767). It is extended in the northwest-southeast direction. Its position is not consistent with the present enhanced XRT position, as noted by P60 (Perley, GCN 17769).
GCN Circular 17770
Subject
GRB 150428A: RATIR optical observations
Date
2015-04-28T06:46:58Z (11 years ago)
Edited On
2024-11-07T19:46:24Z (a year ago)
From
Owen Littlejohns at Az State U <olittlej@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>
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), 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 150428A (Page, et al., GCN 17765) 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 2015/04 28.14 to 2015/04
28.27 UTC (1.80 to 4.88 hours after the BAT trigger), obtaining a
total of 2.49 hours exposure in the r, i and z bands.
We find no uncatalogued source within the Swift-XRT error circle
(Osborne, et al., GCN 17768). In comparison with the SDSS DR9, we
obtain the following upper limits (3-sigma):
r > 23.94
i > 23.90
z > 19.56
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. We note that the source detected
by GROND (Knust, et al., GCN 17767) and P60 (Perley, GCN 17769) is not
consistent with the enhanced X-ray position. For the GROND source, in
comparison with the SDSS DR9, we obtain the following detections and
upper limit (3-sigma):
r = 23.41 +/- 0.22
i = 22.75 +/- 0.14
z > 19.56
The RATIR observations of the GROND source, therefore, do not show
evidence of fading between the GROND and RATIR epochs of observations.
Further RATIR observations are ongoing.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
GCN Circular 17769
Subject
GRB 150428A: P60 observations
Date
2015-04-28T06:00:44Z (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 field of GRB 150428A (Page et al., GCN 17765) using the
Palomar 60-inch robotic telescope starting at UT 03:40:50 on the night
of 2015-04-28, acquiring a sequence of r, i, and z-band exposures under
excellent seeing conditions.
Stacking a series of 9x180s i-band images between 03:44 and 04:25 UT, we
detect no sources within the enhanced XRT error circle (Osborne et al.,
GCN 17768) down to a limiting magnitude of i > 22.7 mag at a median time
of 2.65 hours after the trigger. We note that the source reported by
GROND (Knust et al., GCN 17767) is not within the enhanced error circle,
but we marginally detect this source at a similar magnitude (i = 22.8
+/- 0.3 mag).
GCN Circular 17768
Subject
GRB 150428A: Enhanced Swift-XRT position
Date
2015-04-28T05:34:00Z (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 147 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 150428A, 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 = 188.53878, +6.95390 which is equivalent
to:
RA (J2000): 12h 34m 9.31s
Dec (J2000): +06d 57' 14.0"
with an uncertainty of 1.9 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 17767
Subject
GRB 150428A: GROND Dark Burst Host Candidate
Date
2015-04-28T04:15:54Z (11 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
F. Knust (MPE Garching), D. A. Kann (TLS Tautenburg), T. Kruehler (ESO),
and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 150428A (Swift trigger 639275; Page et al.,
GCN #17765) 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 02:24 UT on 2015-04-28, 53 minutes after the GRB
trigger, following a delay due to the labeling of the event as "not a GRB"
in the BACODINEs. They were performed at an average seeing of 0".9 and at
an average airmass of 1.2.
We detect a source at (J2000):
RA = 12:34:09.26
Dec. = +06:57:08.7
with an error of 0".5 in each coordinate.
Based on 25 min of total exposure time in g'r'i'z' centered 1.41 hrs after
the GRB, we estimate the following preliminary magnitudes (all in AB
system):
g' = 24.1 +/- 0.4 mag,
r' = 23.0 +/- 0.1 mag,
i' = 22.7 +/- 0.1 mag, and
z' = 23.2 +/- 0.2 mag.
At this time, we cannot establish fading. At this position, we also detect
a source in the SDSS, which implies that this would be the host galaxy of
this GRB. We note the hydrogen column density as derived from X-rays
(Page et al., GCN #17765) is much higher than the (very low) Galactic NH,
implying this may be an optically dust-suppressed event.
Given magnitudes are calibrated against SDSS field stars and are not
corrected for the expected Galactic foreground extinction corresponding to
a reddening of E_(B-V)=0.02 mag in the direction of the burst (Schlegel et
al. 1998).
GCN Circular 17765
Subject
GRB 150428A: Swift detection of a burst
Date
2015-04-28T01:53:52Z (11 years ago)
From
Kim Page at U.of Leicester <klp5@leicester.ac.uk>
K. L. Page (U Leicester), M. M. Chester (PSU), N. Gehrels (NASA/GSFC),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), T. Sakamoto (AGU),
B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf
of the Swift Team:
At 01:30:40 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 150428A (trigger=639275). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 188.543, +6.981 which is
RA(J2000) = 12h 34m 10s
Dec(J2000) = +06d 58' 51"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex structure
with a duration of about 50 sec. The peak count rate
was ~1700 counts/sec (15-350 keV), at ~17 sec after the trigger.
The XRT began observing the field at 01:33:36.7 UT, 175.9 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 188.53889, 6.95211 which is equivalent
to:
RA(J2000) = 12h 34m 09.33s
Dec(J2000) = +06d 57' 07.6"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 105 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.63 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 9.3
(+6.64/-5.03) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 179 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 none of
the XRT error circle. 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 0.02.
Burst Advocate for this burst is K. L. Page (klp5 AT leicester.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.)