GRB 141005A
GCN Circular 16903
Subject
GRB 141005A: iTelescope.Net T21 Optical Observation
Date
2014-10-07T12:57:06Z (12 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
D. Kawamura, T. Sakamoto, A. Yoshida (AGU)
We observed the field of GRB 141005A detected by Swift (trigger #614415;
D'Elia et al., GCN Circ. 16882) with the iTelescope.Net (http://www.itelescope.net)
T21 (0.43 m Planewave) telescope located at the New Mexico Skies Observatory
(NM, USA).
60 images of 20 sec exposures and 20 images of 60 sec exposures were taken in the
R filter starting from October 5 05:27:55 (UT) about 15 minutes after the trigger
and stopped on October 5 06:33:49 (UT). We do not detect the optical afterglow
both in the individual images and the stacked image at the enhanced X-ray
afterglow position (Beardmore et al., GCN Circ. 16888). The estimated five sigma
upper limit of the combined image (total exposure of 2400 sec) is ~18.4 using
the USNO-B1 catalog.
GCN Circular 16901
Subject
GRB 141005A: Additional P60 imaging and afterglow confirmation
Date
2014-10-07T06:04:59Z (12 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report:
We obtained a second epoch of imaging at the location of the optical
afterglow (Perley et al., GCN 16884; Littlejohns et al., GCN 16885;
Schmidl et al., GCN 16898) of GRB 141005A (D'Elia et al., GCN 16882)
with the robotic Palomar 60 inch telescope. Observations were obtained
in the r', i', and z' filters beginning at 2:31 UT on 2014 October 6
(0.89 d after the burst).
A source is clearly detected at the location of the afterglow candidate
originally reported in GCN 16884 (Perley et al). As noted therein, a
source is also present at this location in pre-outburst SDSS imaging of
this field.
To search for variability at this location, we performed digital image
subtraction with the P60 data, using the images from 2014 October 6 as a
reference template. We find clear evidence for fading in the i-band
(and marginal evidence in r and z-bands), confirming that this source is
indeed the optical afterglow of GRB 141005A but is blended with a bright
(i' ~ 21.7 mag) host galaxy or foreground object. Assuming no
contribution of the afterglow to our template images, we measure i' =
20.24 +/- 0.10 at 5:18 UT on 2014 October 5 (i.e., 5 min after the Swift
trigger).
GCN Circular 16898
Subject
GRB 141005A: GROND observations
Date
2014-10-06T19:22:24Z (12 years ago)
From
Sebastian Schmidl at TLS Tautenburg <schmidl@tls-tautenburg.de>
S. Schmidl (TLS Tautenburg), J. F. Graham, and J. Greiner
(both MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 141005A (Swift trigger 614415; V. D'Elia et
al., GCN #16882) 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).
We detect a source consistant with the position reported by Perley et al.
(GCN #16884). From coadded observations, starting on October 05 and
spanning from 23:50 to 00:04 UT, we report the following preliminary
magnitudes and upper limits (AB magnitude system) of:
g' > 21.6,
r' = 21.7 +/- 0.2,
i' = 21.7 +/- 0.2,
z' = 21.2 +/- 0.2,
J > 20.5,
H > 19.9, and
K > 18.2.
Given magnitudes and upper limits 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)=0.17 mag in
the direction of the burst (Schlegel et al. 1998).
GCN Circular 16897
Subject
Konus-Wind observation of GRB 141005A
Date
2014-10-06T18:30:02Z (12 years ago)
From
Anastasia Tsvetkova at Ioffe Institute <tsvetkova@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 141005A (Swift-BAT trigger 614415:
D'Elia, GCN 16882; Krimm et al., GCN 16893;
Fermi-GBM detection: Roberts, GCN 16889)
triggered Konus-Wind at T0=18787.727 s UT (05:13:07.727).
The burst light curve shows a single pulse with a duration of ~3 s.
The emission is seen up to ~1 MeV.
As observed by Konus-Wind, the burst
had a fluence of 2.3(-0.2,+0.3)x10^-6 erg/cm2,
and a 64-ms peak energy flux, measured from T0+0.390 s,
of 1.6(-0.5,+0.5)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 1 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.34(-0.49,+0.58),
and Ep = 104(-14,+18) keV (chi2 = 33/55 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -2.37 (chi2 = 31/54 dof).
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB141005_T18787/
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 16895
Subject
GRB 141005A: Swift-XRT refined Analysis
Date
2014-10-05T17:28:03Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.C. Stroh (PSU), B.P. Gompertz (U. Leicester), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), M. de Pasquale (INAF-IASFPA), A.
Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows (PSU),
J.A. Kennea (PSU) and V. D'Elia report on behalf of the Swift-XRT team:
We have analysed 10 ks of XRT data for GRB 141005A (D'Elia et al. GCN
Circ. 16882), from 79 s to 29.1 ks after the BAT trigger. The data
comprise 120 s in Windowed Timing (WT) mode (the first 7 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 16888).
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.33 (+/-0.06).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.03 (+0.23, -0.21). The
best-fitting absorption column is 3.3 (+1.0, -0.9) x 10^21 cm^-2, in
excess of the Galactic value of 1.6 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.7 x 10^-11 (5.7 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.3 (+1.0, -0.9) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^21 cm^-2
Excess significance: 3.2 sigma
Photon index: 2.03 (+0.23, -0.21)
If the light curve continues to decay with a power-law decay index of
1.33, the count rate at T+24 hours will be 3.4 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.3 x
10^-14 (1.9 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00614415.
This circular is an official product of the Swift-XRT team.
GCN Circular 16894
Subject
GRB 141005A: Swift/UVOT Upper Limits
Date
2014-10-05T17:20:24Z (12 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and V. D'Elia (ASDC) report on behalf of the
Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 141005A
94 s after the BAT trigger (D'Elia et al., GCN Circ. 16882).
This GRB was observed also by Fermi GBM (Roberts, GCN Circ. 16889), and
in the r and i bands (P60: Perley et al., GCN Circ. 16884, RATIR:
Littlejohn et al.,GCN Circ. 16885). A nearby galaxy was reported by
Perley et al., and is also seen in the UVOT images.
No optical afterglow consistent with the XRT position (Beardmore et
al. GCN Circ. 16888), or the P60 position is detected in the initial
UVOT exposures, although the event data for the UVOT b-band show a
slight brightening peaking around T+700s..
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u_FC 94 344 246 >20.1
v 5960 7392 393 >19.4
b 349 6980 639 >20.2
u 94 6775 786 >20.6
w1 5138 6570 393 >19.9
m2 4932 7445 441 >20.2
w2 5754 7186 393 >20.6
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.17 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 16893
Subject
GRB 141005A: Swift-BAT refined analysis
Date
2014-10-05T17:19:05Z (12 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), N. Gehrels (GSFC),
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 the recent telemetry downlink,
we report further analysis of BAT GRB 141005A (trigger #614415)
(D'Elia, et al., GCN Circ. 16882). The BAT ground-calculated position is
RA, Dec = 291.103, 36.098 deg, which is
RA(J2000) = 19h 24m 24.7s
Dec(J2000) = +36d 05' 54.1"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 6%.
The mask-weighted light curve shows a single peak starting at ~T-1 sec,
peaking at ~T+2 sec, and ending at ~T+7 sec. T90 (15-350 keV) is 4.34 +- 1.08 sec
(estimated error including systematics).
The time-averaged spectrum from T+0.19 to T+5.66 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.33 +- 0.18. The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.68 sec in the 15-150 keV band
is 4.2 +- 0.8 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/614415/BA/
GCN Circular 16889
Subject
GRB 141005A: Fermi GBM Detection
Date
2014-10-05T15:32:52Z (12 years ago)
From
Oliver Roberts at UCD/Fermi <oliver.roberts@ucd.ie>
O. Roberts (UCD) reports on behalf of the Fermi GBM Team:
"At 05:13:06.97 UT on the 5th of October 2014, the Fermi
Gamma-Ray Burst Monitor triggered and located GRB 141005A
(trigger 434178789 / 141005217) which was also detected by
Swift (V. D'Elia et al. 2014, GCN 16682). The GBM on-ground
location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 107 degrees.
The GBM light curve shows a single pulse with a duration (T90)
of about 3 seconds (50-300 keV). The time-averaged spectrum
from T0-0.26 s to T0+3.07 s is best fit by a power law
function with an exponential high-energy cutoff. The power law
index is -0.30 +/- 0.11 and the cutoff energy, parameterised
as Epeak, is 138 +/- 8 keV.
A Band function fits the spectrum equally well with
Epeak= 119 +/- 10 keV, alpha = -0.06 +/- 0.2 and
beta = -2.7 +/- 0.3.
The event fluence (10-1000 keV) in this time interval is
2.6 E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+1.5 seconds in the 10-1000 keV band
is 3.7 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalogue."
---------------------------------------------------------------------------------------------------------------------------------------------
Dr. Oliver J. Roberts BSc PhD
Space Science and Advanced Materials Research Group,
School of Physics,
University College Dublin,
Belfield,
Dublin 4,
Ireland
+353(0)1-716-2202
GCN Circular 16888
Subject
GRB 141005A: Enhanced Swift-XRT position
Date
2014-10-05T10:38:56Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 2816 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 141005A, 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 = 291.09317, +36.09496 which is equivalent
to:
RA (J2000): 19h 24m 22.36s
Dec (J2000): +36d 05' 41.9"
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 16885
Subject
GRB 141005A: RATIR Optical Observations
Date
2014-10-05T07:29:03Z (12 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 141005A (D'Elia, et al., GCN 16882) 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 2014/10 5.22 to 2014/10 5.27 UTC (0.05
to 1.34 hours after the BAT trigger), obtaining a total of 1.07 hours
exposure in the r and i bands.
We note evidence of the source reported by P60 (Perley, et al., GCN 16884),
with marginal evidence for fading throughout the epoch of RATIR
observations.
Further analysis is ongoing.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 16884
Subject
GRB 141005A: P60 probable afterglow deteaction
Date
2014-10-05T06:53:57Z (12 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech) reports on behalf of a larger collaboration:
The Palomar 60-inch robotic telescope automatically triggered on the
Swift-BAT alert for GRB 141005A (GCN 16882, D'Elia et al.) and began
observations of the field at 05:16:28 UT, 202 seconds after the BAT
trigger. A sequence of cycling 60-second r, i, and z band images were
acquired, ending at 05:33:20 UT.
In the initial images we identify a source inside the SPER XRT error
circle at the following position:
RA = 19:24:22.392
dec = +36:05:42.26
(J2000, +/- 0.3")
The source is faint and probably fading, from r = 20.6 +/- 0.2 and i =
20.0 +/- 0.2 in the initial exposures to r = 21.4 +/- 0.3 and i = 21.3
+/- 0.4 in the final exposures. The source is also present in archival
imaging of the field from SDSS. Measuring the flux of the source in the
same aperture in these images yields magnitudes of g=21.9, r=21.6,
i=21.3, z=20.7.
These observations suggest a faint optical afterglow superimposed on a
host galaxy or Galactic foreground star. More observations are
encouraged to characterize this object.
GCN Circular 16882
Subject
GRB 141005A: Swift detection of a burst
Date
2014-10-05T05:27:58Z (12 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
V. D'Elia (ASDC), S. D. Barthelmy (GSFC), L. Izzo (URoma/ICRA),
D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and
M. H. Siegel (PSU) report on behalf of the Swift Team:
At 05:13:06 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 141005A (trigger=614415). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 291.108, +36.069, which is
RA(J2000) = 19h 24m 26s
Dec(J2000) = +36d 04' 10"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a single peak
with a duration of about 5 sec. The peak count rate
was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 05:14:39.5 UT, 92.9 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 291.09313, 36.09517 which
is equivalent to:
RA(J2000) = 19h 24m 22.35s
Dec(J2000) = +36d 05' 42.6"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 103 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 consistent with the Galactic value of 1.56
x 10^21 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 250 seconds with the U filter starting 93
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 18.0 mag. No correction has been made for the expected extinction
corresponding to E(B-V) of 0.17.
Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.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.)