GRB 130907A
GCN Circular 15240
Subject
GRB 130907A: Maidanak optical observations
Date
2013-09-21T17:24:34Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Pozanenko (IKI), A. Volnova (IKI), B. Hafizov (UBAI), O. Burhonov
(UBAI) report on behalf of larger GRB follow-up collaboration:
We observed the field of Swift GRB 130907A (Page et al., GCN 15183) with
AZT-22 telescope equipped with SNUCAM of Maidanak observatory starting
Sep., 10 (UT) 11:04:47. We obtained 2 frames with exposures of 300 s in
R filter. On stacked images we clearly detect the source reported by Lee
et al., (GCN 15192). The astrometry of the source is following
RA(J2000) 14 23 34.01
Dec(J2000) +45 36 36.6
with uncertainty of 0.18 arcsec in both coordinates.
The details of the photometry are following:
t_start, filter Exposure, t-t0, OT
(UT) sec mid,days
11:04:47 R 2*300 2.56166 21.44 +/- 0.16
The photometry is based on a nearby SDSS-DR9 star J142338.63+453547.2
with R mag = 18.181 +/- 0.013 (transformation by Lupton 2005)
GCN Circular 15223
Subject
GRB 130907A: Continued RATIR Optical and NIR Observations
Date
2013-09-13T04:41:50Z (12 years ago)
Edited On
2024-11-07T19:52:17Z (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>
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 130907A (Page et al., GCN 15183) 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 2013/09 13.13 to 2013/09 13.16 UTC (125.49 to
126.24 hours 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.
For the source reported in Lee et al. (GCN 15192), in comparison with SDSS
DR9 and 2MASS, we obtain the following upper limits (3-sigma) in the AB
magnitude system (not corrected for Galactic extinction in the direction of
the GRB) :
r > 22.68
i > 22.62
Z > 21.30
Y > 20.70
J > 20.42
H > 19.69
We conclude from our most constraining limit (i-band), that the source has
faded by at least 0.9 mags since our observation 2 nights ago (Butler et
al., GCN 15209). These magnitudes are now significantly fainter than the
DR9 catalog magnitudes of SDSS galaxy mentioned by Lee et al.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
GCN Circular 15220
Subject
GRB 130907A: MASTER refined analysis
Date
2013-09-12T18:46:58Z (12 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Gorbovskoy, V. Lipunov, D.Denisenko, V.Kornilov, A.Belinski, N.Tyurina,
D.Kuvshinov, N.Shatskiy, P.Balanutsa, A.Kuznetsov, V.V.Chazov,
A.Sankovich, D.Zimnukhov
Sternberg Astronomical Institute, Moscow 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
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University
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 Kislovodsk was pointed to the GRB130907A 18 sec after notice
time and 43 sec after GRB time at 2013-09-07 21:42:00 UT in two
polarizations. The observations were performed at low elevation (zenith
angle 84 deg)and under the changing transparency conditions. The OT (Page et. al.
GCN15183) appears on the 4th image in the series and is visible on four
consecutive images (20, 30, 40 and 50 sec exposures) in both tubes with
the signal-to-noise ratio from 3 to 6. Starting with T0+5 min, the image
quality was further deteriorating with the OT visible only on the sum of
two pairs of synchronous images.
Our photometry results are presented in Table 1.
Table 1.
-------
Start date and time exptime T_start-T_trig T_mid-T_trig P| mag. err_P P- mag err_P- P| + P- err. (P| + P-)
-----------------------+--------+----------------+--------------+--------+---------+----------+---------+----------+---------------
2013-09-07 21:42:00.31 10 47 52 <10.5 --- <10.5 --- <11.0 ---
2013-09-07 21:42:22.79 10 69 74 <10.5 --- <10.5 --- <11.0 ---
2013-09-07 21:42:43.59 20 91 101 <11.0 --- <11.0 --- <11.5 ---
2013-09-07 21:43:16.66 20 123 133 12.2 0.2 13.0 0.3 12.5 0.2
2013-09-07 21:43:47.44 30 154 169 13.3 0.4 13.6 0.6 13.5 0.4
2013-09-07 21:44:29.95 40 197 217 13.7 0.5 13.7 0.6 13.9 0.5
2013-09-07 21:45:21.88 50 249 274 13.7 0.5 14.4 0.8 14.0 0.6
2013-09-07 21:46:23.87 60+80 311 387 <13.8 --- <13.7 --- 13.9 0.6
*) All time intervals in seconds. P| and P- is an unfiltered magnitude
with RA and DEC orientated polaroid correspondingly.
The sign '<' before magnitude means the value is upper limit.
The light curve and movie available here
http://master.sai.msu.ru/static/GRB/GRB130907A/grb130907A.html
The epoch of our observations completely covers Swift BAT weak, soft peak
from T+210 sec to T+240 sec (Cummings et. al. GCN15202).
Our first automatic and not so exact (due to difficult observing
conditions) estimation of the OT magnitude, given in the previous
telegram (Gorbovskoy et. al GCN15184), belongs to epoch of the 5th
exposure with t_mid=217 sec. after the trigger. This fact isn't clear from
the telegram text that could mislead some researchers.
We apologize for this inaccuracy.
The message may be cited.
GCN Circular 15211
Subject
GRB 130907A: AMI radio detection
Date
2013-09-11T13:29:18Z (12 years ago)
From
Alexander van der Horst at U of Amsterdam <A.J.vanderHorst@uva.nl>
G.E. Anderson, R.P. Fender, T.D. Staley (University of Southampton),
A.J. van der Horst and B.A. Rowlinson (University of Amsterdam)
report on behalf of a large collaboration:
"We observed the position of the GRB 130907A afterglow at 15 GHz with
the Arcminute Microkelvin Imager at September 8 09.90 UT to 11.90 UT,
i.e. 12.2 - 14.2 hours after the burst (GCN 15183).
We detect a radio source at the position of the optical counterpart
(GCN 15187) with a flux density of 1.06 +/- 0.11 mJy.
These observations were triggered via the system described in
Staley et. al (2013, MNRAS, 428, 3114).
Further follow-up observations are planned."
GCN Circular 15209
Subject
GRB 130907A: Continued RATIR Optical and NIR Observations
Date
2013-09-11T05:14:23Z (12 years ago)
Edited On
2024-11-07T20:01:16Z (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>
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 130907A (Page et al., GCN 15183) 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 2013/09 11.12 to 2013/09 11.16 UTC (77.18 to
78.08 hours after the BAT trigger), obtaining a total of 0.71 hours
exposure in the r and i bands and 0.30 hours exposure in the Z and Y.
For the source reported in Lee et al. (GCN 15192), in comparison with SDSS
DR9 and 2MASS, we obtain the following detections and upper limits
(3-sigma):
r 22.40 +/- 0.14
i 21.73 +/- 0.10
Z > 21.80
Y > 21.05
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. The source has faded by about 0.4
mags in the r and i bands relative to our observations last night (Butler
et al., GCN 15208).
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
GCN Circular 15208
Subject
GRB 130907A: RATIR Optical and NIR Observations
Date
2013-09-10T05:56:06Z (12 years ago)
Edited On
2024-11-07T18:52:49Z (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 130907A (Page et al., GCN 15183) 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 2013/09 10.12 to 2013/09 10.16 UTC (53.18 to
54.12 hours after the BAT trigger), obtaining a total of 0.71 hours
exposure in the r and i bands and 0.30 hours exposure in the Z, Y, J, and H
bands.
For the source reported in Lee et al. (GCN 15192), in comparison with SDSS
DR9 and 2MASS, we obtain the following detections and upper limits
(3-sigma):
r 21.92 +/- 0.12
i 21.38 +/- 0.09
Z > 21.37
Y > 20.87
J > 20.58
H > 19.97
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. The source has faded by about two
magnitudes in all bands since our measurements two nights ago (Lee et al.,
GCN 15192). We note that the source intensity in the r and i bands is now
comparable to the cataloged values for the spatially coincident galaxy SDSS
J142333.95+453626.2.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
GCN Circular 15207
Subject
GRB 130907A: WSRT radio detection
Date
2013-09-10T00:48:04Z (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 130907A afterglow at 4.9 GHz with
the Westerbork Synthesis Radio Telescope at September 9 09.99 UT to
20.69 UT, i.e. 1.51 - 1.96 days after the burst (GCN 15183).
We detect a radio source with a flux density of 0.19 +/- 0.03 mJy
at the position of the optical counterpart (GCN 15187).
We would like to thank the WSRT staff for quickly scheduling and
obtaining these observations."
GCN Circular 15205
Subject
GRB 130907A: Further Swift-BAT refined analysis
Date
2013-09-09T19:41:01Z (12 years ago)
From
Hans Krimm at NASA-GSFC <hans.krimm@nasa.gov>
H. A. Krimm (GSFC/USRA), J. R. Cummings (GSFC/UMBC), D. M. Palmer (LANL),
C. B. Markwardt (GSFC) for the Swift-BAT team):
Using the complete data set from T-239 to T+963 sec, we report further analysis
of BAT GRB 130907A (trigger #569992) (Page, et al., GCN Circ. 15183). The
initial report on the BAT data was presented in Cummings, et al., GCN Circ. 15202.
The burst started while Swift was slewing from another target, and the burst
location came into the BAT coded field of view at about T-80 seconds. The
initial pair of peaks at T-117 that triggered Konus-Wind (Golenetskii, et al.,
GCN Circ. 15203) and INTEGRAL/SPI-ACS (Savchenko, et al., GCN Circ. 15204) were
seen from outside the coded field in the non-weighted rates.
The mask-weighted light curve is described in Cummings, et al., GCN Circ. 15202.
Although there are no discrete peaks later than T+240 seconds, the burst is
still detected in the mask-weighted rate out to T+963 sec, when this data cuts
off and continues to be detected onboard in a 64-second image starting at
T+1388, and possibly later. Since the BAT event data does not cover the full
extent of the burst, we cannot reliably calculate T90 at this point, but it is
at least 360 seconds.
The time-averaged spectrum from T-73.7 to T+767.4 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.17 +- 0.02. The fluence in the 15-150 keV band is 1.4 +- 0.01 x 10^-4
erg/cm2. We note that this time interval does not cover the entire burst
duration, so should be considered a lower limit.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/569992/BA/
GCN Circular 15204
Subject
GRB 130907A: INTEGRAL/SPI-ACS light curve
Date
2013-09-09T15:33:25Z (12 years ago)
From
Volker Beckmann at APC <beckmann@apc.univ-paris7.fr>
V. Savchenko, V. Beckmann (APC), C. Ferrigno, E. Bozzo, M. Beck (ISDC),
J. Borkowski (CAMK/Torun), D. G�tz (CEA/Saclay), S. Mereghetti (INAF/IASF-Milano), A. von Kienlin, A. Rau (MPE), and K. Hurley (SSL/Berkeley)
GRB 130907A, detected by Swift/BAT (Palmer et al. GCN 15183), Fermi/LAT (Vianello et al. GCN 15196) and Konus-Wind (Frederiks et al, GCN 15203), has been independently detected by the SPI Anti-Coincidence System (ACS) on-board INTEGRAL. The SPI-ACS light curve reveals the rich multi-peak structure of this burst starting at 2013-09-07T21:39:16. Several bright peaks are followed by a major activity episode at about T0+100s. The maximum count-rate of 94,000 counts/sec (approximately corresponding to 1e-5 erg/cm2/s in the 75 keV-1 MeV range, Vigano and Mereghetti 2009) over the time bin length of 50 msec is reached at T0+115s. The total duration of this GRB is
about 250 seconds.
The SPI-ACS light curve of this GRB is available at:
http://www.isdc.unige.ch/integral/ibas/cgi-bin/ibas_acs_web.cgi/?trigger=2013-09-07T21-39-16.00-00000-00000-0
All SPI-ACS light curves are available (both as images and data files) at http://isdc.unige.ch/Soft/ibas/ibas_acs_web.cgi.
The light curves, binned at 50 ms, are derived from 91 independent detectors with different lower energy thresholds (mainly between 50 keV and 150 keV). SPI-ACS has no upper energy threshold and can detect photons with energies up to at least 100 MeV. The ACS response varies as a function of the GRB incident angle. For these reasons we caution that the count rates cannot be easily translated into physical flux units.
GCN Circular 15203
Subject
Konus-Wind observation of GRB 130907A
Date
2013-09-09T10:52:42Z (12 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, and T. Cline on behalf
of the Konus-Wind team, report:
The long-duration intense GRB 130907A
(Swift-BAT trigger 569992: Page, et al., GCN 15183;
Cummings, et al., GCN 15202)
triggered Konus-Wind at T0=77955.997 s UT (21:39:15.997),
or ~118 s before the BAT trigger.
The burst light curve shows multiple bright, partially overlapped
pulses from ~T0-4 s till ~T0+210~s.
The emission is seen up to ~15 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB130907_T77955/
As observed by Konus-Wind, the burst
had a fluence of (7.9 � 0.5)x10-4 erg/cm2,
and a 256-ms peak flux, measured from T0+139.008 s,
of (2.2 � 0.1)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum (measured from T0 to T0+206.080 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.91 � 0.02,
the high energy photon index beta = -2.42 � 0.07,
the peak energy Ep = 394 � 11 keV,
chi2 = 90/92 dof.
The spectrum near the maximum count rate
(measured from T0+139.264 s to T0+143.872 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.65 � 0.03,
the high energy photon index beta = -2.22 � 0.05,
the peak energy Ep = 390 � 16 keV,
chi2 = 111/96 dof.
Assuming the NOT redshift z=1.238 (de Ugarte Postigo, et al., GCN 15187),
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 of GRB 130907A:
the isotropic energy release E_iso is (3.3 � 0.1)x10^54 erg,
the peak luminosity L_iso is (2.0 � 0.1)x10^53 erg/s,
and the rest-frame peak energy Ep,i = (880 � 25) keV
All the quoted results are preliminary.
GCN Circular 15202
Subject
GRB 130907A, Swift-BAT refined analysis
Date
2013-09-09T01:35:56Z (12 years ago)
From
Hans Krimm at NASA-GSFC <hans.a.krimm@nasa.gov>
J. R. Cummings (GSFC/UMBC),S. D. Barthelmy (GSFC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),
M. J. Page (UCL-MSSL),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-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 130907A (trigger #569992)
(Page, et al., GCN Circ. 15183). The BAT ground-calculated position is
RA, Dec = 215.898, 45.602 deg which is
RA(J2000) = 14h 23m 35.5s
Dec(J2000) = +45d 36' 08.0"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a very complicated structure with six main
peaks from T-55 sec to T+95 sec. Each of these peaks shows several sub-peaks.
The strongest peak is at ~T+57 sec. After T+95 sec, the count rate drops
significantly, but doesn't return all the way to the background level. Then
there is another weak, soft peak from T+210 sec to T+240 sec. This late peak
is coincident with the start of a long flare seen in the XRT. There may be
further BAT emission beyond the end of the currently available event data.
T90 (15-350 keV) is 115.14 +- 0.67 sec (estimated error including systematics).
The time-averaged spectrum from T-50.7 to T+234.6 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.11 +- 0.02. The fluence in the 15-150 keV band is 1.2 +- 0.0 x 10^-4 erg/cm2.
The 1-sec peak photon flux measured from T+57.66 sec in the 15-150 keV band
is 25.6 +- 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/569992/BA/
GCN Circular 15201
Subject
GRB 130907A: T21 optical observations
Date
2013-09-08T22:35:10Z (12 years ago)
From
Veli-Pekka Hentunen at Taurus Hill Obs,A95 <veli-pekka.hentunen@kassiopeia.net>
Veli-Pekka Hentunen, Markku Nissinen, Harri Vilokki and Tuomo Salmi (Taurus
Hill Observatory, Varkaus, Finland) report:
We have detected GRB 130907A optical afterglow at iTelescope observatory
T21 (Mayhill, New Mexico) 0.43-m/6.8 astrograph and FLI-PL6303E CCD.
Six unfiltered images and seven photometric R filter images with 300 sec
were made.
The afterglow was detected at the following position RA 14:23:34.06 and
DEC +45:36:27.1 J2000.
The following magnitudes were obtained from the observations using
NOMAD1 1356-0257141 (R=15.220) as a comparison star:
Tmid(h)+T0 Filter Exp. time Mag Mag err.
4.70 unfiltered 3x300 20.00CR 0.49
5.22 R 7x300 20.06R 0.47
5.77 unfiltered 3x300 20.36CR 0.47
GCN Circular 15200
Subject
GRB 130907A: VLA detection
Date
2013-09-08T22:25:42Z (12 years ago)
From
Alessandra Corsi at GWU <corsi@email.gwu.edu>
A. Corsi (GWU) reports on behalf of a larger collaboration:
We imaged the position of GRB 130907A (Page et. al. GCN 15183)
with the Karl G. Jansky Very Large Array (VLA) in K-band, starting at
about 4 hours after the burst. A provisional reduction shows a source
consistent with the location of the GRB optical afterglow reported by
de Ugarte Postigo et al. (GCN 15187). At this time, we estimate a
preliminary flux of about 1.2 mJy at 24.5 GHz.
Further observations are planned.
GCN Circular 15199
Subject
GRB 130907A: Swift-XRT refined Analysis
Date
2013-09-08T21:53:03Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
D.N. Burrows (PSU), J.A. Kennea (PSU), P.A. Evans (U. Leicester), B.P.
Gompertz (U. Leicester), J.P. Osborne (U. Leicester), V. D'Elia (ASDC),
A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), V. Mangano (PSU) and
M.J. Page report on behalf of the Swift-XRT team:
We have analysed 20 ks of XRT data for GRB 130907A (Page et al. GCN
Circ. 15183), from 70 s to 60.0 ks after the BAT trigger. The data
comprise 3.7 ks in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Osborne et al. (GCN. Circ 15198).
The late-time light curve (from T0+5.7 ks) can be modelled with a
power-law decay with a decay index of alpha=1.686 (+0.017, -0.016).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.761 (+0.015, -0.014). The
best-fitting absorption column is 1.96 (+0.05, -0.04) x 10^21 cm^-2,
in excess of the Galactic value of 1.0 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.98 (+/-0.06) and a
best-fitting absorption column of 1.85 (+0.17, -0.16) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.9 x 10^-11 (5.5 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.85 (+0.17, -0.16) x 10^21 cm^-2
Galactic foreground: 1.0 x 10^20 cm^-2
Excess significance: 17.7 sigma
Photon index: 1.98 (+/-0.06)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00569992.
This circular is an official product of the Swift-XRT team.
GCN Circular 15198
Subject
GRB 130907A: Enhanced Swift-XRT position
Date
2013-09-08T20:33:59Z (12 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 11208 s of XRT Photon Counting mode data and 18 UVOT
images for GRB 130907A, 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 = 215.89216, +45.60725 which is equivalent
to:
RA (J2000): 14h 23m 34.12s
Dec (J2000): +45d 36' 26.1"
with an uncertainty of 1.4 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 15197
Subject
Errata of GRB name in GCN 15196: should have been GRB 130907A instead of GRB 120916A
Date
2013-09-08T19:23:00Z (12 years ago)
From
Giacomo Vianello at SLAC <giacomov@slac.stanford.edu>
We made an error in the Subject of GCN 15196.
It should have been :
"GRB 130907A: Fermi-LAT detection of a burst"
instead of:
"GRB 120916A: Fermi-LAT detection of a burst"
We apologize for this error and for the confusion this might have caused.
GCN Circular 15195
Subject
GRB 130907A: Swift/UVOT Detection
Date
2013-09-08T17:37:39Z (12 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates (UCL-MSSL) and M. J. Page (UCL-MSSL)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 130907A
74 s after the BAT trigger (Page et al., GCN Circ. 15183).
A source consistent with the XRT position (Page et al. GCN Circ. 15183)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 14:23:34.04 = 215.89183 (deg.)
Dec (J2000) = +45:36:27.1 = 45.60753 (deg.)
with an estimated uncertainty of 0.50 arc sec. (radius, 90% confidence).
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 74 224 147 15.45 +/- 0.02
v 616 636 20 16.29 +/- 0.16
b 542 562 20 16.78 +/- 0.12
u 286 536 246 15.87 +/- 0.04
w1 666 1113 117 18.54 +/- 0.31
m2 641 1606 117 >19.2
w2 592 786 38 >18.7
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 15194
Subject
GRB 130907A: Early Tautenburg detections, red afterglow
Date
2013-09-08T13:13:03Z (12 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
S. Schmidl (TLS Tautenburg), D. A. Kann (MPE Garching), S. Klose, S.
Stecklum, F. Ludwig (all TLS Tautenburg), and J. Greiner (MPE Garching)
report:
We observed the field of the intense GRB 130907A (Swift trigger 569992,
Page et al., GCN #15183) with the 1.34m Tautenburg Schmidt telescope.
Starting at 22:02:18 UT (21 minutes after the trigger), we obtained in
total 3 x 120 sec Ic-band images and 12 Rc-band images of 120 sec and 60
sec exposure. Observations were obtained at high airmass of 2.6 - 3.2. The
afterglow is clearly detected on all frames.
Using the star at RA (J2000) = 14:23:28.93, Dec. (J2000) = +45:37:33.65,
for which we derive Rc = 15.10, Ic = 14.51 using SDSS magnitudes and the
transformations of Lupton (2005), we derive preliminary magnitudes for the
first image in each filter of:
Time (d) Filter mag error
0.0152 Ic 15.26 0.03
0.0172 Rc 16.57 0.03
not corrected for the very small reddening of 0.01 mag along the line of
sight (Schlegel et al. 1998).
We note Swift was slewing when GRB 130907A started, the extended raw BAT
light curve (http://gcn.gsfc.nasa.gov/notices_s/sw00569992000msbx.gif)
shows the GRB began about 120 seconds before Swift T_0. Adding this time
to our observing times, we find the data is well-described by a single
power-
law decay with alpha = 1.39 +/- 0.02. The detection by Trotter et al. (GCN
#15191) agrees excellently with the extrapolation of our data, while the
RATIR detection (Lee et al., GCN #15192), after transforming to Vega mag,
indicates that the decay has slowed, which is confirmed by Trotter et al.
(GCN #15193). The very early detection by Gorbovskoy et al. (GCN #15184)
lies several magnitudes under a back-extrapolation of our data.
We derive a very large Rc-Ic color of about 1.2 mag from the fit,
indicating possible strong reddening (see also the Skynet light curve, GCN
#15193, and the multicolor RATIR mags, GCN #15192), which would be in
accordance with the very strong absorption lines detected by de Ugarte
Postigo et al. (GCN #15187).
This message may be cited.
GCN Circular 15193
Subject
GRB 130907A: Skynet DSO-14/Yerkes-41/GORT confirmation of a fading afterglow
Date
2013-09-08T06:28:32Z (12 years ago)
From
Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet <atrotter@physics.unc.edu>
A. Trotter, D. Reichart, J. Haislip, A. LaCluyze, K. McLin, L. Cominsky,
A. B. Smith, D. Caton, L. Hawkins, V. Hoette, K. Cudworth, D. Harper, R.
Kron, T. Linder, R. Russell, E. Struble, T. Berger, H. T. Cromartie, R.
Egger, A. Foster, N. Frank, K. Ivarsen, M. Maples, J. Moore, M.
Nysewander, and J. A. Crain report:
In Trotter et al. (GCN 15191), we reported Skynet observations of the
Swift/XRT localization of GRB 130907A (Page et al., GCN 15183, Swift
trigger 569992) with the 14" telescope at the Appalachian State
University Dark Sky Observatory (DSO-14) in NC, USA (R and I bands), and
with the 41" telescope of Yerkes Observatory in WI, USA (r' and i'
bands). Skynet continued observing the field with the 14" GLAST Optical
Robotic Telescope (GORT) at the Hume observatory in CA, USA.
From t=5.9h - 8.2h post-trigger, GORT took a total of 54x160s exposures
in the R and I bands. We confirm a fading afterglow at the position
reported by de Ugarte Postigo et al. (GCN 15187) and by Lee et al. (GCN
15192). The afterglow fades from I=18.1 mag at t=3.2h to I=19.2 mag at
t=8.2h, consistent with a power-law index alpha~-0.9.
A preliminary light curve is at:
http://skynet.unc.edu/grb/grb130907a_2.png
R and I magnitudes are in the Vega system, and r' and i' magnitudes are
in the AB system, calibrated to 5 APASS stars in the field. Magnitudes
have not been corrected for line-of-sight Milky Way dust extinction,
with expected E(B-V)=0.011 (Schlegel et al. 1998).
No further Skynet observations are scheduled.
GCN Circular 15192
Subject
GRB 130907A: RATIR Optical and NIR Afterglow Confirmation
Date
2013-09-08T05:11:53Z (12 years ago)
Edited On
2024-11-07T19:54:06Z (a year ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
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>
William H. Lee (UNAM), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), 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 130907A (Page et al., GCN 15183) 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 2013/09 8.14 to 2013/09 8.15 UTC (5.57
to 6.03 hours 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 a source at 14:23:34.01 +45:36:27.0 J2000 (+/- 0.5") with
r = 20.01 +/- 0.03
i = 19.30 +/- 0.02
Z = 18.78 +/- 0.05
Y = 18.48 +/- 0.06
J = 18.13 +/- 0.06
H = 17.63 +/- 0.05
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
This source is outside the Swift-XRT error circle, but is only 0.8
arcsec from the transient source reported by de Ugarte Postigo et al.
(GCN 15187) and 0.2 arcsec from the transient source reported by Trotter
et al. (GCN 15191). From the close positional coincidence and fading
magnitudes (r of 16.7, 19.6, and 20.0), we conclude all three
observations are of the optical transient.
The transient source is 0.5 arcsec from the faint galaxy SDSS
J142333.95+453626.2, but is 1-2 magnitudes brighter in riZ.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
GCN Circular 15191
Subject
GRB 130907A: Skynet DSO-14/Yerkes-41 detections of a possible afterglow
Date
2013-09-08T02:40:43Z (12 years ago)
From
Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet <atrotter@physics.unc.edu>
A. Trotter, J. Haislip, A. LaCluyze, J. Moore, N. Frank, D. Reichart, A.
Smith, D. Caton, L. Hawkins, V. Hoette, D. Harper, R. Kron, K. Cudworth,
E. Struble, R. Russell, T. Linder, T. Berger, H. T. Cromartie, R. Egger,
A. Foster, K. Ivarsen, M. Maples, M. Nysewander, and J. A. Crain report:
Skynet observed the Swift/XRT localization of GRB 130907A (Page et al.,
GCN 15183, Swift trigger 569992) with the 14" telescope at the
Appalachian State University Dark Sky Observatory (DSO-14) in NC, USA (R
and I bands), and with the 41" telescope of Yerkes Observatory in WI,
USA (r' and i' bands).
Starting at 2013-09-08, 00:43 UT (t=3.03h post-trigger) and continuing
until 17:41 UT (t=35.5m-4.65h post-trigger), Skynet took a total of 42
160s exposures. We detect an uncatalogued optical source in stacked
images at RA 14:23:34.03, Dec +45:36:26.7 (J2000.0), consistent with the
afterglow position reported by de Ugarte Postigo et al. (GCN 15187), and
~8" south of the Swift-XRT localization. At t=3.4h post-trigger, R~19.6
mag. The time range of our observations is not sufficient to confirm
whether the source is indeed fading.
A preliminary light curve is at:
http://skynet.unc.edu/grb/grb130907a.png
R and I magnitudes are in the Vega system, and r' and i' are in the AB
system, calibrated to 5 APASS stars in the field. Magnitudes have not
been corrected for line-of-sight Milky Way dust extinction with expected
E(B-V)=0.011 (Schlegel et al. 1998).
Skynet observations are ongoing.
GCN Circular 15187
Subject
GRB 130907A: NOT redshift
Date
2013-09-07T23:44:37Z (12 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D. Xu (DARK/NBI), D. Malesani (DARK/NBI),
J. Gorosabel (IAA-CSIC/UPV-EHU), P. Jakobsson (U. Iceland) and J. Kajava (NOT) report
on behalf of a larger collaboration:
We observed the optical afterglow of GRB 130907A (Page et al., GCN 15183; Gorbovskoy
et al., GCN 15184) with the NOT equipped with the AlFOSC spectrograph and camera.
The transient is clearly detected in our acquisition images, taken in a clear filter, at the
following coordinates:
RA(J2000) = 14:23:34.08
Dec(J2000) = +45:36:26.7
Using R-band values from nearby USNO stars, we get a magnitude R = 16.7 +- 0.1 at a
mean time of 0.41 hr after the GRB, where the error is dominated by calibration
uncertainties.
A single spectrum of 900 s covering the range from 3800 to 8000 AA, with a resolution of
~700, was obtained with a mean epoch of 0.598 hr after the burst. The spectrum presents
a strong continuum with deep spectral features of AlIII, FeII, MgII and MgI at a common
redshift of z=1.238 (wavelength calibration based on archival data), which we identify as
the redshift of the GRB.
GCN Circular 15184
Subject
GRB 130907A: MASTER early OT observations
Date
2013-09-07T22:14:19Z (12 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina,
N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov,
D.Denisenko, A.Sankovich
Sternberg Astronomical Institute, Moscow 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
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University
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 Kislovodsk was pointed to the GRB130907A 18 sec after notice
time and 43 sec after GRB time at 2013-09-07 21:42:00 UT in two
polarizations. On our first images we found optical transient within
SWIFT error-box (Page et. al. GCN15183). The object approximate magnitude
is about 15.0 mag.
Observations are made at very long zenith distance z=86 deg.
The observations and reduction is continued.
The message may be cited.
GCN Circular 15183
Subject
GRB 130907A: Swift detection of a burst with an optical counterpart
Date
2013-09-07T21:53:31Z (12 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
M. J. Page (UCL-MSSL), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), C. Pagani (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL) and
V. N. Yershov (UCL-MSSL) report on behalf of the Swift Team:
At 21:41:13 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130907A (trigger=569992). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 215.877, +45.616 which is
RA(J2000) = 14h 23m 31s
Dec(J2000) = +45d 36' 58"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex multi-peaked
structure with a duration of about 120 sec. The peak count rate
was ~60000 counts/sec (15-350 keV), at ~25 sec after the trigger.
The XRT began observing the field at 21:42:19.3 UT, 66.6 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 215.8926, 45.6094 which is equivalent to:
RA(J2000) = +14h 23m 34.22s
Dec(J2000) = +45d 36' 33.8"
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This
location is 45 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
The initial flux in the 0.1 s image was 6.33e-08 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 74 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 14:23:34.03 = 215.89181
DEC(J2000) = +45:36:27.1 = 45.60753
with a 90%-confidence error radius of about 0.61 arc sec. This position is 7.0
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.55 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.01.
Burst Advocate for this burst is M. J. Page (m.page 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.)