- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Tue 02 Jul 13 00:05:48 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 45
TRIGGER_NUM: 394416326
GRB_RA: 228.150d {+15h 12m 36s} (J2000),
228.306d {+15h 13m 14s} (current),
227.571d {+15h 10m 17s} (1950)
GRB_DEC: +16.583d {+16d 34' 60"} (J2000),
+16.533d {+16d 31' 60"} (current),
+16.770d {+16d 46' 12"} (1950)
GRB_ERROR: 13.02 [deg radius, statistical plus systematic]
GRB_INTEN: 152 [cnts/sec]
DATA_SIGNIF: 9.50 [sigma]
INTEG_TIME: 2.048 [sec]
GRB_DATE: 16475 TJD; 183 DOY; 13/07/02
GRB_TIME: 323.08 SOD {00:05:23.08} UT
GRB_PHI: 243.00 [deg]
GRB_THETA: 85.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO: 1.54
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 82% GRB
2nd_MOST_LIKELY: 13% Generic SGR
DETECTORS: 0,0,0, 0,0,0, 0,1,1, 0,0,0, 0,0,
SUN_POSTN: 101.20d {+06h 44m 47s} +23.04d {+23d 02' 16"}
SUN_DIST: 114.89 [deg] Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN: 28.67d {+01h 54m 40s} +13.17d {+13d 10' 28"}
MOON_DIST: 144.52 [deg]
MOON_ILLUM: 32 [%]
GAL_COORDS: 22.42, 55.73 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 220.26, 33.08 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 213.88,14.02 [deg].
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Tue 02 Jul 13 00:06:00 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 55
TRIGGER_NUM: 394416326
GRB_RA: 218.640d {+14h 34m 34s} (J2000),
218.799d {+14h 35m 12s} (current),
218.053d {+14h 32m 13s} (1950)
GRB_DEC: +17.100d {+17d 06' 00"} (J2000),
+17.041d {+17d 02' 29"} (current),
+17.318d {+17d 19' 06"} (1950)
GRB_ERROR: 6.86 [deg radius, statistical only]
DATA_SIGNIF: 18.20 [sigma]
DATA_INTERVAL: 4.096 [sec]
GRB_DATE: 16475 TJD; 183 DOY; 13/07/02
GRB_TIME: 323.08 SOD {00:05:23.08} UT
GRB_PHI: 249.00 [deg]
GRB_THETA: 78.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 4143 (Gnd S/W Version number)
SUN_POSTN: 101.20d {+06h 44m 47s} +23.04d {+23d 02' 16"}
SUN_DIST: 107.04 [deg] Sun_angle= -7.8 [hr] (East of Sun)
MOON_POSTN: 28.67d {+01h 54m 41s} +13.17d {+13d 10' 30"}
MOON_DIST: 148.17 [deg]
MOON_ILLUM: 32 [%]
GAL_COORDS: 15.47, 64.17 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 209.98, 30.48 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS: Fermi-GBM Ground-calculated Coordinates.
COMMENTS: This Notice was ground-generated -- not flight-generated.
- GCN Circular #14967
L. P. Singer (Caltech), S. B. Cenko (NASA/GSFC), M. M. Kasliwal (Carnegie
Observatories), D. A. Brown (Syracuse), O. Yaron (Weizmann Institute of
Science), E. Bellm (Caltech), S. Caudill (Milwaukee), S. Tinyanont (Harvey
Mudd), D. Khatami (Pomona), and A. J. Weinstein (Caltech) report on behalf
of the intermediate Palomar Transient Factory (iPTF) collaboration:
We have imaged 72 deg^2 of the vicinity of the final localization of the
Fermi-GBM trigger 394416326 with the Palomar 48 inch Oschin telescope
(P48). Images were obtained in the Mould R filter in 2 visits to each of
10 fields. Within the GBM error circle, we detect a bright point source at
the position:
RA(J2000) = 14h 29m 14.78s
DEC(J2000) = +15d 46' 26.4"
which is 3.8 degrees away from the center of the final GBM localization
(68% confidence radius of 3.99 degrees). At 04:17 UT on 2013 July 2 (4.2
hours after the Fermi-GBM trigger), we measure a magnitude of R = 17.4 for
the source, dubbed iPTF13bxl. Nothing was detected at this location in
previous P48 images of the field taken on 2011 February 5 to a limiting
magnitude of R > 21.1.
Automatic follow-up of iPTF13bxl was obtained with the robotic Palomar 60
inch telescope beginning at 4:10 UT on 2013 July 3 (28.1 hours after the
burst trigger). At this time we measure a magnitude of r' = 18.7. Assuming
the source decays as a single power-law from the time of our P48 to
discovery to this time, we infer a decay index of 0.54.
We observed iPTF13bxl with the Double Beam Spectrograph on the Palomar
200-inch (P200) on 2013-07-03 04:24:04, 28.3 hours after the burst. The
spectrum has a largely featureless blue continuum with no strong, narrow
features in emission or absorption between 3800A and 9000A.
We triggered target-of-opportunity observations of iPTF13bxl with the
Swift satellite, beginning at 00:50 UT on 2013 July 3 (1.03 d after the
Fermi-GBM trigger). A total exposure time of 1.4 ks was obtained with the
on-board X-Ray Telescope (XRT). A bright source is detected at the
location of iPTF13bxl in the XRT. We measure a preliminary count rate of
0.3 ct s^-1 at this time. Assuming a power-law spectrum with a photon
index of 2, this corresponds to a 0.3-10.0 keV X-ray flux of ~ 10^-11 erg
cm^-2 s^-1.
We note that close to iPTF13bxl are two SDSS sources:
SDSS J142914.75+154626.0, at a separation of 0.6", a faint source
classified as a star with r = 23.01, and
SDSS J142914.57+154619.3, at a separation of 7.6", a bright galaxy
with a photometric redshift of 0.09 +/- 0.02.
Without a secure spectroscopic redshift, we cannot definitively associate
this source with the Fermi-GBM GRB. The bright X-ray emission and
relatively steep decay in the optical seem to rule out an (unrelated)
supernova, but other potential interlopers remain. Follow-up observations
are ongoing and encouraged to help identify the nature of this source.
- ATEL 5189
L. P. Singer (Caltech), S. B. Cenko (NASA/GSFC), M. M. Kasliwal
(Carnegie Observatories), D. A. Brown (Syracuse), O. Yaron (Weizmann
Institute of Science), E. Bellm (Caltech), S. Caudill (Milwaukee),
S. Tinyanont (Harvey Mudd), D. Khatami (Pomona), and A. J. Weinstein
(Caltech) report on behalf of the intermediate Palomar Transient Factory
(iPTF) collaboration:
We have imaged 72 deg^2 of the vicinity of the final localization of the
Fermi-GBM trigger 394416326 with the Palomar 48 inch Oschin telescope
(P48). Images were obtained in the Mould R filter in 2 visits to each of
10 fields. Within the GBM error circle, we detect a bright point source
at
the position:
RA(J2000) = 14h 29m 14.78s
DEC(J2000) = +15d 46' 26.4"
which is 3.8 degrees away from the center of the final GBM localization
(68% confidence radius of 3.99 degrees). At 04:17 UT on 2013 July 2 (4.2
hours after the Fermi-GBM trigger), we measure a magnitude of R = 17.4
for
the source, dubbed iPTF13bxl. Nothing was detected at this location in
previous P48 images of the field taken on 2011 February 5 to a limiting
magnitude of R > 21.1.
Automatic follow-up of iPTF13bxl was obtained with the robotic Palomar 60
inch telescope beginning at 4:10 UT on 2013 July 3 (28.1 hours after the
burst trigger). At this time we measure a magnitude of r' = 18.7. Assuming
the source decays as a single power-law from the time of our P48 to
discovery to this time, we infer a decay index of 0.54.
We observed iPTF13bxl with the Double Beam Spectrograph on the Palomar
200-inch (P200) on 2013-07-03 04:24:04, 28.3 hours after the burst. The
spectrum has a largely featureless blue continuum with no strong, narrow
features in emission or absorption between 3800 A and 9000 A.
We triggered target-of-opportunity observations of iPTF13bxl with the
Swift satellite, beginning at 00:50 UT on 2013 July 3 (1.03 d after the
Fermi-GBM trigger). A total exposure time of 1.4 ks was obtained with the
on-board X-Ray Telescope (XRT). A bright source is detected at the
location of iPTF13bxl in the XRT. We measure a preliminary count rate of
0.3 ct s^-1 at this time. Assuming a power-law spectrum with a photon
index of 2, this corresponds to a 0.3-10.0 keV X-ray flux of ~ 10^-11 erg
cm^-2 s^-1.
We note that close to iPTF13bxl are two SDSS sources:
SDSS J142914.75+154626.0, at a separation of 0.6", a faint source
classified as a star with r = 23.01, and
SDSS J142914.57+154619.3, at a separation of 7.6", a bright galaxy
with a photometric redshift of 0.09 +/- 0.02.
Without a secure spectroscopic redshift, we cannot definitively associate
this source with the Fermi-GBM trigger. The bright X-ray emission and
relatively steep decay in the optical seem to rule out an (unrelated)
supernova, but other potential interlopers remain. Follow-up observations
are ongoing and encouraged to help identify the nature of this source.
- GCN Circular #14968
C. Guidorzi (Ferrara U.), C.G. Mundell, I.A. Steele (LJMU),
on behalf of a large collaboration report:
On 2013 July 03 (09:03:30 UT) we began observing the field of the
possible optical afterglow of Fermi394416326 (Singer GCN Circ. 14967)
with the 2-m Faulkes Telescope North in Hawaii.
Observations were carried out using the BVRi filters.
We clearly detect the optical counterpart discovered by
Singer et al. with the following magnitudes
Time from GRB Filter Exposure[s] Magnitude
(days)
----------------------------------------------------
1.38 i' 100 18.61 +- 0.07
1.38 R 120 18.46 +- 0.05
----------------------------------------------------
The calibration was performed using the i' magnitudes of
SDSS catalogue field stars and the R magnitudes obtained
using the transformations by Jordi et al (2006).
- GCN Circular #14970
H. Levato and C. Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
C. Mallamaci, C. Lopez and F. Podest
Observatorio Astronomico Felix Aguilar (OAFA)
E. Gorbovskoy, D. Denisenko, V. Lipunov, V. Kornilov, A. Kuznetsov,
D. Kuvshinov, N. Tyurina, N. Shatskiy, P. Balanutsa, D.
Zimnukhov, V.V. Chazov
Lomonosov Moscow State University, Sternberg Astronomical Institute
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V. Sennik
Kislovodsk Solar Station of the Pulkovo Observatory
K. Ivanov, S. Yazev, N.M. Budnev, O. Gres, O. Chuvalaev, V.A. Poleshchuk
Irkutsk State University
V. Yurkov, Yu. Sergienko, D. Varda, E. Sinyakov
Blagoveschensk Educational State University, Blagoveschensk
V. Krushinski, I. Zalozhnich, A. Popov, A. Bourdanov, A. Punanova
Ural Federal University
MASTER-ICATE robotic very wide field cameras (FOV=2x384 square degrees,
D=72mm, f/1.2, 1 pix = 22 arcsec, http://observ.pereplet.ru) located
in Argentina (Observatorio Astronomico Felix Aguilar,
http://master.sai.msu.ru:8080/) were pointed to the
Fermi-GBM trigger 394416326 55 sec after GRB time and 49 sec FERMI trigger
Time at 2013-07-02 00:06:18 UT.
We haven't found optical transient (Singer et. al. GCN 14967) on single
(exp = 5 sec) images with upper limit V<11m and coadded image made of
first 58 frames (5 sec exposure without time gap) and total exposure of
290 seconds with upper limit V<12.5m. Our magnitudes are calibrated
against V magnitudes from Tycho-2 catalog.
This upper limit does not contradict the power law decay with an index of
0.54 inferred by Singer et al. in GCN 14967.
The reduction of the whole data set is continuing.
This message can be cited.
- GCN Circular #14971
T. Cheung (NRL), G.Vianello (Stanford), S. Zhu (NASA/GSFC), J. Racusin
(NASA/GSFC), V. Connaughton (UAH) and B. Carpenter (NASA/GSFC) report
on behalf of the Fermi-LAT team:
At 00:05:23.079 UTC on July 02, 2013, Fermi GBM triggered on GRB
130702A / Fermi394416326 (trigger 394416326). The LAT detected high
energy emission from this GRB, which was also detected in the optical
band by iPTF (Singer et al., GCN 14967) and confirmed by FTN (Guidorzi
et al., GCN 14968).
The best LAT on-ground location is found to be:
RA, DEC = 216.4, 15.8 (J2000), with an error radius of 0.5 deg (90%
containment, statistical error only)
This position is 4 deg from the best GBM position (RA, Dec = 218.81,
+12.25 with a 4 deg radius), and 0.8 deg from the position of the
optical afterglow. A preliminary IPN triangulation of the burst using
GBM and Konus-Wind data gives an annulus with center RA, DEC =
260.8992, -20.7746 (J2000) of radius 50.85 degrees and a width of
(-32.73,+18.42) deg (3 sigma). The center of this annulus is 6.05 deg
(0.99 sigma) from the LAT location (Private Communication, with
possible IPN refinements using data from distant spacecraft).
The best LAT localization for the source was ~75 deg from the LAT
boresight at the time of the trigger, i.e., outside the nominal field
of view of the LAT (~65 deg), but it entered the FOV at T0+250 s to
exit again at T0 + 2200 s.
The data from the Fermi LAT in such time interval show a significant
increase in the event rate within 10 degree of the source location,
with a significance of more than 5 sigmas. This analysis has been
carried out with the P7SOURCE_V6 class. More than 5 photons above 100
MeV are observed within 2200 seconds. The highest energy photon is a
1.5 GeV event which is observed 260 seconds after the GBM trigger.
The Fermi LAT point of contact for this burst is Giacomo Vianello
(giacomov@stanford.edu).
The Fermi LAT is a pair conversion telescope designed to cover the
energy band from 20 MeV to greater than 300 GeV. It is the product of
an international collaboration between NASA and DOE in the U.S. and
many scientific institutions across France, Italy, Japan and Sweden.
- GCN Circular #14972
Andrew C. Collazzi (NASA/ORAU), V. Connaughton (UAH)
report on behalf of the Fermi GBM Team:
"At 00:05:23.08 UT on 2 July 2013, the Fermi Gamma-ray Burst
Monitor (GBM) triggered and located GRB 130702A (trigger 394416326 /
130702.004). The on-ground calculated location, using the Fermi GBM
trigger data, is RA = 218.8, Dec = +12.25 (J2000 degrees, equivalent
to J2000 14h 35m, +12d 15'), with a statistical uncertainty of 4.0
degrees (radius, 1-sigma containment, statistical only; there is
additionally a systematic error which is currently estimated to be
2 to 3 degrees). The angle from the Fermi LAT boresight is 75
degrees.
The GBM trigger is possibly associated with an optical transient
reported by Singer et al. (GCN 14697) and Guidorzi et al. (GCN 14698).
This event was also detected above 100 MeV by the Fermi LAT
(Cheung et al., GCN 14971).
The GBM light curve shows a FRED-like burst with a duration (T90)
of about 59 s (50-300 keV). The burst has a 1.024-s peak flux of
7.03 +/- 0.86 ph/s-cm^2. The time-averaged spectrum from
T0+0.003 to T0+16.384 s is well fit by power-law function with
alpha = -1.65 +/- 0.02. The fluence (10-1000 keV) in this time
interval is (6.3 +/- 2.0)E-06 erg/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
- GCN Circular #14973
P. D'Avanzo (INAF-OAB), B. Porterfield, D. N. Burrows, M. Siegel
(PSU), A. Melandri (INAF-OAB), P. A. Evans (Univ. Leicester) report on
behalf of the Swift team:
The Fermi GBM and LAT instruments detected GRB 130702A at 00:05:23 UT
on July 2, 2013 (Fermi trigger 394416326; Cheung et al. 2013, GCN Circ
14971). Followup by the Palomar Transient Factory (PTF) located a
possible optical counterpart, iPTF13bxl (Singer et al. 2013, GCN Circ.
14967). A subsequent TOO observation by Swift located a coincident X-
ray counterpart, making this a likely counterpart of GRB 130702A
(Singer et al. 2013, GCN Circ 14971). Here we report the results of
the analysis of Swift XRT and UVOT data for this object.
We have analysed 3.4 ks of XRT data for this object, from 89.1 ks to
95.7 ks after the Fermi/GBM trigger. The data are entirely in Photon
Counting (PC) mode. Using 3411 s of PC mode data and 5 UVOT images,
we find an enhanced XRT position (using the XRT-UVOT alignment and
matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =
217.31166, +15.77388 which is equivalent to:
RA (J2000): 14h 29m 14.80s
Dec(J2000): +15d 46' 26.0"
with an uncertainty of 1.5 arcsec (radius, 90% confidence). This
position is consistent with the optical counterpart reported by Singer
et al. 2013 (GCN Circ. 14967; see also Guidorzi et al. 2013, GCN Circ.
14968).
The light curve displays variability consistent with a fading
behaviour. More observations are scheduled to confirm whether the
source is fading.
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.99 (+/-0.16). The best-
fitting absorption column is 6.3 (+3.4, -3.1) x 10^20 cm^-2, in
excess of the Galactic value of 1.7 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.6 x 10^-11 (4.2 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 6.3 (+3.4, -3.1) x 10^20 cm^-2
Galactic foreground: 1.7 x 10^20 cm^-2
Excess significance: 2.4 sigma
Photon index: 1.99 (+/-0.16)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00032876.
The Swift/UVOT began settled observations of the field of GRB 130702A
89111 s after the GBM detection. A source consistent with the P48
position (Singer et al. 2013, GCN Circ. 14967) is detected in the
initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 14:29:14.77 = 217.31155 (deg.)
Dec (J2000) = +15:46:26.5 = 15.77403 (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 89232 95967 3414 18.26 +/- 0.04
The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B V) = 0.04 in the direction of
the burst (Schlegel et al. 1998).
This circular is an official product of the Swift team.
- GCN Circular #14974
K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team,
V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, on behalf of the Fermi
GBM team,
S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
D. Svinkin, and T. Cline, on behalf of the Konus-Wind team, and
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C.
Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report:
MESSENGER (GRNS), INTEGRAL (SPI-ACS), Fermi-GBM, and Konus-Wind have detected
GRB 130702A (= Fermi 394416326) so far. We have triangulated this burst to an
annulus centered at RA, Dec (2000) = 293.0106 degrees, -18.3126 degrees,
whose radius is 82.0991 +/- 0.4594 degrees (3 sigma). The distance
between the annulus center line and the iPTF optical transient reported
by Singer et al. (GCN 14967) is 0.16 degrees, strengthening the association
of the transient with the GRB. A map has been posted at
ssl.berkeley.edu/ipn3/130702 showing the annulus, the Fermi LAT position
(GCN 14971), and the optical transient. This localization may be
improved.
- GCN Circular #14975
D. Xu (DARK/NBI), A. Esamdin, L. Ma, X. Zhang (XAO) report:
We observed the field of GRB 130702A / Fermi394416326 (Singer et al.,
GCN 14967; Cheung et al., GCN 14971; Collazzi et al., GCN 14972) using
the 1m telescope located at Mt. Nanshan, Xinjiang Astronomical
Observatory, China. We obtained 3x600s R-band frames, starting from
17:43:25 UT on 2013-07-03 (i.e., 1.735 days after the Fermi trigger).
The optical transient reported in Singer et al. (GCN 14967) is clearly
detected in each of the frames. However, it is slightly overlapped
with its nearby bright galaxy, SDSS J142914.57+154619.3, due to seeing
and technical constraints. The transient has decayed to R~18.9,
calibrated with two bright SDSS stars converted to Johnson R. The
continuous decay makes it likely the optical counterpart of GRB
130702A / Fermi394416326.
- GCN Circular #14976
D. Xu (DARK/NBI), A. Esamdin, L. Ma, X. Zhang (XAO) report:
We observed the field of GRB 130702A / Fermi394416326 (Singer et al.,
GCN 14967; Cheung et al., GCN 14971; Collazzi et al., GCN 14972) using
the 1m telescope located at Mt. Nanshan, Xinjiang Astronomical
Observatory, China. We obtained 3x600s R-band frames, starting from
17:43:25 UT on 2013-07-03 (i.e., 1.735 days after the Fermi trigger).
The optical transient reported in Singer et al. (GCN 14967) is clearly
detected in each of the frames. However, it is slightly overlapped
with its nearby bright galaxy, SDSS J142914.57+154619.3, due to seeing
and technical constraints. The transient has decayed to R~18.9,
calibrated with two bright SDSS stars converted to Johnson R. The
continuous decay makes it likely the optical counterpart of GRB
130702A / Fermi394416326.
- GCN Circular #14977
P. D'Avanzo, A. Melandri (INAF-OAB), G. Andreuzzi, G. Mainella (INAF/FGG)
, report on behalf of the CIBO collaboration:
We observed the optical counterpart of the Fermi GRB 130702A (Cheung et
al. GCN 14971; Collazzi et al. GCN 14972) with the Italian 3.6m TNG
telescope located in Canary Islands, equipped with the DOLoRes imager.
Observations were carried out starting on 2013 Jul 3.955 UT (1.95 days
after the Fermi/GBM trigger).
In a single 300 seconds exposures obtained in the SDSS r band we clearly
detect the optical afterglow reported by Singer et al. (GCN 14697) with a
magnitude of r=19.1 (calibrated against nearby SDSS stars). Further
observations are ongoing.
- GCN Circular #14978
S. Schulze (PUC, MCSS), D. Xu (DARK/NBI), D. A. Kann (TLS Tautenburg), D. Malesani (DARK/NBI), S. Geier (NOT, DARK/NBI), P. Jakobsson (U. Iceland) report on behalf of a larger collaboration:
We observed the field of GRB 130702A (Singer et al., GCN 14967; Cheung et al., GCN 14971; Collazzi et al., GCN 14972) with 2.5m the Nordic Opitcal Telescope (NOT) equipped with ALFOSC. We obtained 1 x 120 s each in the r' and i' bands. Observations started at 23:36:59 UT on July 03 (i.e., 47.53 hrs after the burst).
The source reported in Singer et al. (GCN 14967) is clearly detected in both images. It has an r'-band magnitude of 19.13 +/- 0.01 mag and an i' band magnitude of 18.82 +/- 0.01 mag (AB magnitude). The mid-exposure times are 47.5432 and 47.5900 hrs after trigger in r' and i',. The source faded by ~0.4 mag with respect to Singer et al. (GCN 14967). We create a light curve using the Rc/r' data of of Singer et al. (GCN 14967), Guidorzi et al. (GCN 14968) and Xu et al. (GCN 14975), and find a slope of alpha = 0.58, in agreement with that of Singer et al. Compared to all known GRB afterglows, the afterglow of GRB 130702A is among the brightest, of similar brightness as that of GRB130427A at the time of our observation (Xu et al. 2013, arXiv:1305.6832).
Calibration was done against SDSS J142915.86+154510.0 and SDSS J142911.60+154535.1 from SDSS DR9. We did not correct for Galactic foreground extinction.
- GCN Circular #14980
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), Willia=
m
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)=
,
Jos=E9 A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=FAs Gonz=E1lez (UN=
AM),
Carlos Rom=E1n-Z=FA=F1iga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley=
(GSFC)
report:
We observed the field of GRB 130702A (Singer et al., GCN 14967; Cheung et
al., GCN 14971; Collazzi & Connaughton, GCN 14972) with the Reionization
and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold
Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra Sa=
n
Pedro M=E1rtir from 2013/07 4.16 to 2013/07 4.25 UTC (51.79 to 53.82 hour=
s
after the BAT trigger), obtaining a total of 1.42 hours exposure in the r=
'
and i' bands and 0.60 hours exposure in the Z, Y, J, and H bands.
At the position of the source from Singer et al. (GCN 14967), in comparis=
on
with SDSS DR9 and 2MASS, we obtain the following detections:
r' 19.22 +/- 0.01
i' 19.06 +/- 0.02
Z 18.85 +/- 0.03
Y 18.70 +/- 0.03
J 18.72 +/- 0.03
H 18.56 +/- 0.03
These magnitudes are in the AB system and not corrected for Galactic
extinction in the direction of the GRB. Further observations are underway.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro
M=E1rtir.
- GCN Circular #14979
D. A. Perley (Caltech) and M. Kasliwal (Carnegie) report on behalf of a
larger collaboration:
We observed the location of the probable optical counterpart of Fermi
GRB 130702A (Singer et al., GCN 14967; Cheung et al., GCN 14971;
Collazzi & Connaughton, GCN 14972) with the Combined Array for Research
in Millimeter Astronomy (CARMA) on 2013-07-04 between 00:28:21 and
05:56:31 UT, 2.01-2.24 days after the GBM trigger, at a frequency of 93
GHz (3 mm). Weather conditions were poor initially but improved
somewhat over the course of the integration. In a preliminary
reduction of the data we detect a millimeter source coincident with the
location of the optical counterpart with a flux of approximately ~2 mJy.
We thank John Carpenter and the CARMA staff for their support.
- GCN Circular #14981
D. A. Perley, L. P. Singer (Caltech), and S. B. Cenko (GSFC) report:
We obtained additional observations of the location of the probable
afterglow of GRB 130702A with the Palomar 60-inch robotic telescope. A
series of repeated imaging sequences were taken in B, g, r, i, and z
filters during intermittent clouds. Example photometry from one
sequence is as follows:
tstart(d) exp(s) filt mag unc
2.20405 120 i = 19.129 +/- 0.05
2.20565 120 r = 19.297 +/- 0.05
2.20728 120 B = 19.635 +/- 0.07
2.20888 120 z = 19.204 +/- 0.16
2.21048 120 g = 19.519 +/- 0.08
Compared to our previous night's P60 observations (Singer et al., GCN
14967) and referenced to the GBM trigger time (Collazzi et al., GCN
14972), the fading is consistent with a power law with decay index of
approximately alpha=1.1, steeper than that inferred during the first 24
hours.
- GCN Circular #14982
P. D'Avanzo, A. Melandri (INAF-OAB), P. A. Evans (Univ Leicester) report on behalf of the Swift-XRT team:
We have analysed 6.2 ks of XRT data for the Fermi GRB 130702A (Cheung et al. GCN 14971; Collazzi et al. GCN 14972), from 89.1 ks to 153.4 ks after the Fermi/GBM trigger. The data are entirely in Photon Counting (PC) mode. We confirm the fading of the X-ray afterglow reported in D'Avanzo et al. (GCN 14973).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.57 (+0.21, -0.20).
This circular is an official product of the Swift-XRT team.
- GCN Circular #14983
G. Leloudas (OKC, Stockholm and DARK/NBI), J. P. U. Fynbo (DARK/NBI), S. Schulze (PUC, MCSS), D. Xu (DARK/NBI), D. Malesani (DARK/NBI), S. Geier (NOT, DARK/NBI), Z. Cano(U. Iceland), P. Jakobsson (U. Iceland) report on behalf of a larger collaboration:
We observed the field of GRB 130702A (Singer et al., GCN 14967; Cheung et al., GCN 14971; Collazzi et al., GCN 14972) with the Nordic Opitcal Telescope (NOT) equipped with ALFOSC. In addition to our photometric observations (reported in Schulze et al., GCN 14978), we obtained an optical spectrum, with a total exposure of 2 x 1800 s, using Grism #4 and covering the wavelength range 3750 - 9000 AA at a resolution of 17 AA.
The slit was oriented to cover both the transient source (also dubbed iPTF13bxl) that has been suggested to be the afterglow of GRB 130702A, and the bright SDSS galaxy located 7.6" South of the source (SDSS J142914.57+154619.3; Singer et al., GCN 14967).
The galaxy is found to be at z = 0.145, based on Ca II H & K absorption and emission by [OII] and Halpha. The emission features are weak and we do not detect Hbeta or [OIII]. Overall, and combined with the SDSS colors, this galaxy shows very weak star formation activity.
This redshift is consistent with the redshift of the transient source reported by Mulchaey et al. (ATel 5191) and the description given there. The trace of our NOT spectrum at the location of the transient is mostly featureless and we cannot detect the emission lines reported by Mulchaey et al., probably due to a lower S/N.
The common redshift suggests that the transient source iPTF13bxl is associated with the galaxy SDSS J142914.57+154619.3. If this transient is indeed the afterglow of GRB 130702A at z = 0.145, it implies an E_iso = (3.0 +- 1.0) * 10^50 erg in the 10-1000 keV (Collazzi et al., GCN 14972).
We note that this is an unusual environment for a long GRB: located at a large offset (19.1 kpc in projection) from a relatively passive galaxy. However, we cannot exclude that more sources in the field, including the fainter (r ~ 23 mag) object at 0.6" from the transient (SDSS J142914.75+154626.0; Singer et al., GCN 14967) might be at the same redshift. A possible confirmation of the GRB nature of this transient will be the emergence of an associated supernova. At z = 0.145, a supernova similar to SN 1998bw will peak at R ~ 19.8 mag about 20 days after the GRB, and will be easily detectable.
- GCN Circular #14984
P. D'Avanzo (INAF-OAB), V. D'Elia (ASI/ASDC), G. Tagliaferri, A. Melandri (INAF-OAB), D. Malesani (DARK/NBI), M. Della Valle (INAF-OAC), E. Pian (SNS) report on behalf of the CIBO collaboration:
We observed the optical counterpart of the Fermi GRB 130702A (Cheung et al. GCN 14971; Collazzi et al. GCN 14972) with the Italian 3.6m TNG telescope located in Canary Islands, equipped with the DOLoRes imager.
In addition to what reported in D'Avanzo et al. (GCN 14977), further observations were carried out between Jul 3.955 UT and Jul 4.022 UT (1.95-2.02 days after the Fermi GBM trigger).
The optical afterglow is clearly detected in the SDSS g, r, and i bands with the following magnitudes:
g=19.3
r=19.1
i=19.0
calibrated against nearby SDSS stars.
We also obtained a 2400 seconds spectrum with the LR-B grism, covering the wavelength range 3900-8200 AA with a resolution of R~600. The spectrum has a high S/N and shows a blue continuum nearly featureless. Very faint emission lines can be interpreted as [OII] 3727.5, [OIII] 4959.0/5006.8 and Halpha 6562.8 at a common redshift of 0.145, consistent with what reported by Mulchaey et al. (ATel 5191) for the optical afterglow spectrum and by Leloudas et al. (GCN circ. 14983) for the spectrum of the nearby SDSS galaxy.
We acknowledge the TNG staff for excellent support, in particular G. Andreuzzi and G. Mainella.
- GCN Circular #14985
J. Mulchaey (Carnegie), M. M. Kasliwal (Carnegie), I. Arcavi
(Weizmann), E. Bellm (Caltech) and D. Kelson (Carnegie) report on
behalf of a larger collaboration:
We obtained a high SNR low-resolution spectrum of iPTF13bxl
(GCN#14967) with IMACS on the 6.5m Magellan telescope at Las Campanas
on 2013 July 3.97 covering 3800A-9500A. We also obtained another
spectrum with the DBSP spectrograph on the 5m Hale telescope at
Palomar at July 4.16. The spectra show a blue continuum with weak
H-alpha and O III emission at z=0.145.
- GCN Circular #14986
S. Golenetskii, R.Aptekar, V. Pal'shin, D. Frederiks, P. Oleynik, M.
Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team report:
The long GRB 130702A (= Fermi 394416326; Optical and X-ray transient
discovery: Singer et al., GCN 14967; Fermi-LAT detection: Cheung et
al., GCN 14971; Fermi GBM detection: Collazzi & Connaughton, GCN 14972;
IPN localization: Huley et al., GCN 14974) was detected by Konus-Wind in
the waiting mode.
The burst light curve shows a FRED-like pulse with a duration of ~26 s.
As observed by Konus-Wind, the burst had a fluence of
6.70(-0.80,+0.82)10^-6 erg/cm2 (in the 20 - 1200 keV energy range).
Fitting the K-W 3-channel time-integrated spectrum (from T0(GBM)-2.8 s
to T0(GBM)+23.7 s) by a simple power-law model yields a power law index
of 1.87 +/- 0.11.
Assuming z = 0.145 (Kasliwal et al., GCN 14985; Leloudas et al. GCN
14983) and a standard cosmology model with H_0 = 71 km/s/Mpc, Omega_M =
0.27, Omega_Lambda = 0.73, the isotropic energy release is E_iso =
6.36(-1.03,+1.34)x10^50 erg in 1 keV to 10 MeV at the GRB rest frame
extrapolating the best power-law function fit.
All the quoted errors are at the 90% confidence level.
The results presented above are preliminary.
The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB130702A/
- GCN Circular #14987
A.J. van der Horst (University of Amsterdam) reports on behalf
of a large collaboration:
"We observed the position of the GRB 130702 afterglow at 4.9 GHz with
the Westerbork Synthesis Radio Telescope at July 4 13.55 UT to
July 5 01.17 UT, i.e. 2.56 - 3.05 days after the burst (GCN 14972).
We detect a radio source with a flux density of 1.23 +/- 0.04 mJy
at the position of the optical counterpart (GCN 14967).
We would like to thank the WSRT staff for quickly scheduling and
obtaining these observations."
- GCN Circular #14988
A. Pozanenko (IKI), A. Volnova (IKI), O. Burhonov (UBAI), I. Molotov
(KIAM) report on behalf GRB follow-up collaboration:
We observed the field of OT (Singer et al., GCN 14967) of GRB 130702�?
(= Fermi 394416326)(Cheung et al., GCN 14971; Collazzi et al., GCN
14972) with AZT-22 telescope of Maidanak observatory on Jul. 3 and Jul.
4 under good weather conditions and seeing (FWHM) of about 1 arcsec. We
clearly detected OT (Singer et al., GCN 14967) in each images of both
epochs.
A preliminary photometry of combined images is based on the two SDSS
stars suggested by Schulze et al. (GCN 14978), i.e.
SDSS J142915.86+154510.0 assuming R = 16.03
SDSS J142911.60+154535.2 assuming R = 15.59
T_start T0+ Filter, Exposure, OT
(UT) (mid, d) (s)
2013-07-03T17:38:18 1.70828 R 6x600 18.69 +/- 0.03
2013-07-04T16:49:20 2.67427 R 6x300 19.31 +/- 0.04
We note that the fading of a lc assuming a power law between our two
epochs is alpha=1.27 which is steeper, than reported in early
observations (Perley et al., GCN 14981).
- GCN Circular #14989
A. Pozanenko (IKI) report on behalf larger GRB follow-up collaboration:
A title of GCN circular #14988 should be read as "GRB 130702A (= Fermi
394416326): Maidanak optical observations"
We apologize for possible inconvenience.
- GCN Circular #14990
A. Corsi (GWU), D. A. Perley (Caltech), and S. B. Cenko (GSFC) report:
We observed the location of iPTF13bxl, the optical counterpart to
GRB 130702A (Singer et al., GCN 14967), with the Karl G. Jansky Very
Large Array in C-band on 2013-07-04 UT, 2.29 days after the GBM trigger.
We detect a radio source at this location with a flux of 1.49 mJy at 5.1 GHz,
and 1.60 mJy at 7.1 GHz. The map noise is 0.011 mJy.
- GCN Circular #14991
GRB 130702A: Continued UVOT Observations
B. Porterfield (PSU), M. Siegel (PSU) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:
Swift reobserved the field of GRB 130702A on July 4 and July 5 2013.
We confirm the slow fading of the source first reported by Singer et al. (GCN Circ.
14973) and previously reported in UVOT by D'Avanzo et al. (GCN Circ. 14973).
We also note that we detect the transient in all four of UVOT's NUV filters,
which is consistent with the low redshift reported by Leloudas et al. (GCN Circ. 14983)
and D'Avanzo et al. (GCN Circ. 14984).
Preliminary detections using the UVOT photometric system (Breeveld et
al. 2011, AIP Conf. Proc. 1358, 373) are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u 151366 153361 1962 18.48+-0.05
u 203252 205246 1962 18.97+/-0.07
u 250292 255654 272 19.51+/-0.26
uvw1 249967 255532 629 19.29+/-0.17
uvm2 251591 252014 415 19.67+/-0.28
uvw2 284670 285309 629 19.26+/-0.14
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).
- GCN Circular #14992
L.P. Xin, J. Y. Wei, Y.L. Qiu, J. Wang, J.S. Deng,
C. Wu, X. H. Han on behalf of EAFON report:
We began to observe the optical counterpart of the Fermi GRB 130702A
( Singer et al. GCN 14967; Collazzi et al. GCN 14972 )
with Xinglong TNT telescope between 14:10:35 and 15:37:22 UT
on 5 June, 2013. 15*300 sec R-band images were obtained.
The optical counterpart was found with a magnitude of R~19.7 mag,
calibrated by USNO-B 1.0 R2 mag, at the mean time of 3.62 days after the burst.
- GCN Circular #14993
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),
Jos=E9 A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=FAs Gonz=E1lez (UNAM),
Carlos Rom=E1n-Z=FA=F1iga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley
(GSFC)
report:
We observed the field of GRB 130702A (Singer et al., GCN 14967; Cheung et
al., GCN 14971; Collazzi & Connaughton, GCN 14972) with the Reionization
and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold
Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra San
Pedro M=E1rtir on the nights of 2013/07/06 and 2013/07/07 (4.25 and 5.26
days
after the BAT trigger), obtaining a total of 1.4 hours exposure in the r'
and i' bands and 0.6 hours exposure in the Z, Y, J, and H bands each night.
At the position of the source from Singer et al. (GCN 14967), in comparison
with SDSS DR9 and 2MASS, we obtain the following detections:
7/06 7/07
r' 19.86 +/- 0.02 19.94 +/- 0.02
i' 19.89 +/- 0.03 20.02 +/- 0.02
Z 19.68 +/- 0.05 19.76 +/- 0.04
Y 19.46 +/- 0.05 19.69 +/- 0.05
J 19.64 +/- 0.07 19.64 +/- 0.06
H 19.36 +/- 0.08 19.69 +/- 0.08
The source appears to be slowly fading, approximately 0.1 mag/day, or
approximately as t^-0.35. This is a significant flattening relative to the
bright fluxes we measured 2 days after the GRB (Butler et al.; GCN 14980).
These magnitudes are in the AB system and not corrected for Galactic
extinction in the direction of the GRB. Further observations are underway.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro
M=E1rtir.
- GCN Circular #14994
S. Schulze (PUC, MCSS), G. Leloudas (OKC, Stockholm and DARK/NBI), D. Xu, J. P. U. Fynbo (DARK/NBI), S. Geier (NOT, DARK/NBI) and P. Jakobsson (U Iceland) report on behalf a larger collaboration:
We observed the field of GRB 130702A (Singer et al., GCN 14967; Cheung et al., GCN 14971; Collazzi et al., GCN 14972) with the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC. We obtained 1 x 150 s in r' and 5 x 60 in i'. Observations started at 23:23:10 UT on July 07 (i.e. 5.97 days after the burst).
We measure r' = 20.03 and i' = 20.21 mag. The afterglow became clearly brighter in r'-band with respect to our observation from the night before. Compared to our first observation on 3 July (Schulze et al. GCN 14978), the colour changed from 0.13 to -0.19 mag. This colour evolution is consistent with Butler et al. (GCN 14993), who reported a colour change of -0.08 mag between 4.25 and 5.26 days after the burst. Such a colour evolution is not expected for a decaying optical afterglow but clearly points to an emerging supernova.
We obtained an optical low-resolution spectrum with the ALFOSC camera starting at 23:45:33 UT. We used grism #4 that covers the wavelength range from 3750 to 9000 AA. The observation consisted of three individual spectra with a total exposure time of 3x1200 s. The flux-calibrated spectrum presents clear deviations from a power law. In particular, we identify two broad emission features peaking at 4900 and 5600 AA with a local minimum at 5200 AA (all observer frame). Assuming z=0.145 (Mulcaey et al. ATel 5191, GCN 14985; Leloudas et al. GCN 14983; D'Avanzo et al. GCN 14984), the spectrum resembles SN 1998bw at phase 7-8 days past explosion (Patat et al. 2001, ApJ, 555, 900).
- GCN Circular #14996
A. Pozanenko (IKI), A. Volnova (IKI), O. Burhonov (UBAI), I. Molotov (KIAM)
report on behalf of larger GRB follow-up collaboration:
We continue observations of the afterglow (Singer et al., GCN 14967) of
GRB
130702=E1 (Cheung et al., GCN 14971; Collazzi et al., GCN 14972) with
AZT-22 telescope of Maidanak observatory. A preliminary photometry of
combined images is based on two SDSS stars suggested by Schulze et al. (GCN
14978) and used in our previous observations (Pozanenko et al, GCN 14988)
T_start T0+ Filter, Exposure, OT
(UT) (mid, d) (s)
2013-07-05T16:25:11 3.6592 R 6x600 19.61+/-0.02
2013-07-06T16:20:12 4.6540 R 6x600 19.71+/-0.03
2013-07-07T16:45:34 5.6717 R 6x600 19.83+/-0.04
2013-07-08T16:49:14 6.6759 R 6x300 19.81+/-0.05
The light curve is based on the photometry of this CGN circular and our
previous observations (Pozanenko et al, GCN 14988) and can be found at
http://grb.rssi.ru/GRB130702A/GRB130702A_MAO_R_lc.png
One can see flattening of the lc after 4 days (initially reported by Butler
et al., GCN 14993) and possible re-brightening on 6.6 days which can
confirm re-brightening of the afterglow (Schulze et al., GCN 14994) and
emerging supernova.
- GCN Circular #14998
S. B. Cenko (NASA/GSFC), A. Gal-Yam (Weizmann Institute), M. M. Kasliwal
(OCIW), D. Stern (JPL), K. Markey, E. Alduena, A. Alduena, and S. Kuo
(Walden) report on behalf of a larger collaboration:
We have obtained further spectroscopy of the optical afterglow (Singer et
al., GCN 14967) of the Fermi-GBM (Collazzi et al., GCN 14972), Fermi-LAT
(Cheung et al., GCN 14971), and IPN (Hurley et al., GCN 14974) GRB
130702A. Observations were obtained with the Double Spectrograph mounted
on the 5 m Palomar Hale telescope beginning at 5:27 UT on 2013 July 8 (6.2
days after the Fermi GBM trigger) and cover the wavelength range from
3400-8900 A. Compared with our previous optical spectra (Mulchaey et al.,
GCN 14985), the source shows a significantly redder continuum. Similar to
Schulze et al. (GCN 14994), a number of broad features are detected that
are reminiscent of canonical GRB-associated supernovae such as SN 2006aj
and SN 1998bw. A plot of our most recent spectrum, alongside comparable
epochs from SN 2006aj (Modjaz et al., ApJL, 2006, 645, 21) and SN 1998bw
(Patat et al., ApJ, 2001, 555, 900), both retrieved from the Weizmann
Interactive Supernova Data Repository (WISEREP;
http://www.weizmann.ac.il/astrophysics/wiserep/) is available here:
http://astro.berkeley.edu/~cenko/public/grb/GRB130702A/GRB130702A_20130708.png
- GCN Circular #15000
V. D'Elia (ASI/ASDC, INAF-OAR), P. D'Avanzo (INAF-OAB), A. Melandri (INAF-OAB), M. Della Valle (INAF-OAC), G. Tagliaferri (INAF-OAB), D. Malesani (DARK/NBI), E. Pian (SNS), L. A. Antonelli, S. Piranomonte (INAF-OAR), A. Harutyunyan, D. Carosati (INAF/TNG) report on behalf of the CIBO collaboration:
We continued monitoring the optical counterpart of the Fermi GRB 130702A (Singer et al., GCN 14967, Cheung et al. GCN 14971; Collazzi et al. GCN 14972) with the Italian 3.6m TNG telescope located in the Canary Islands, equipped with the DOLoRes camera.
In addition to what reported in D'Avanzo et al. (GCN 14977, GCN 14984), further observations were carried out during the nights of Jul 5 and Jul 9 (4 and 8 days after the Fermi GBM trigger).
At a mean t-t0=7.92 days we detect the optical counterpart in the SDSS r band with a magnitude of 19.91 (calibrated against nearby SDSS stars). This value is consistent with our previous epoch obtained 4 days before, confirming the flattening of the optical light curve reported by (Perley et al. GCN 14981, Butler et al. GCN 14993, Schulze et al. GCN 14994, Pozanenko et al. GCN 14996).
We also obtained a 2000 seconds spectrum with the LR-B grism, starting at t-t0=7.92 days, covering the wavelength range 3900-8200 AA with a resolution of R~600. With respect to our previous epoch observation which featured a blue, featureless continuum (D'Avanzo et al. GCN 14984), the spectrum is now considerably redder, and shows a number of broad features similar to GRB-associated supernovae. In particular, the shape of the continuum closely resembles the spectrum of SN 1998bw observed at a similar epoch, despite a prominent feature at 4300 AA rest frame, reminiscent of what seen in SN 2006aj (Pian et al. 2006, Nature, 442, 1011). This confirms the emerging of the supernova already reported by Schulze et al. (GCN 14994) and Cenko et al. (GCN 14998).
We acknowledge support from the TNG visiting astronomer K. Biazzo.
- GCN Circular #15002
Poonam Chandra (NCRA-TIFR) reports:
We carried out Giant Metrewave Radio Telescope (GMRT) observations of
GRB 130702A at 1390 and 610 MHz bands on 2013 July 10.54 UT and 10.72 UT,
respectively. We detect the radio afterglow of the GRB in both bands.
The 1390 MHz band flux density of the afterglow is 792+/-44 uJy and 610 MHz
flux density of the afterglow is 457+/-75 uJy. The map resolutions at 1390
and 610 MHz bands are 2.67"x2.26" and 8.91"x5.50", respectively.
Further observations are planned. We thank GMRT staff for making these
observations possible.
- GCN Circular #15003
A. Pozanenko (IKI), A. Volnova (IKI), O. Burhonov (UBAI), I. Molotov
(KIAM) report on behalf of larger GRB follow-up collaboration:
We continue observations of the afterglow (Singer et al., GCN 14967) of
GRB 130702A (Cheung et al., GCN 14971; Collazzi et al., GCN 14972)
with AZT-22 telescope of Maidanak observatory. A preliminary photometry
of combined images is based on two SDSS stars suggested by Schulze et
al. (GCN 14978) and used in our previous observations (Pozanenko et al,
GCNs 14988, 14996)
T_start T0+ Filter, Exposure, OT
(UT) (mid, d) (s)
2013-07-09T16:50:52 7.6771 R 7x600 19.73+/-0.04
2013-07-10T17:18:05 8.6931 R 6x600 19.64+/-0.03
The light curve can be found at
http://grb.rssi.ru/GRB130702A/GRB130702A_MAO_R_lc.png
It is clearly visible in the lc a rising SN (Schulze et al., GCN 14994;
Cenko et al., GCN 1998; D'Elia et al., GCN 15000).
- GCN Circular #15009
L.P. Xin, J. Y. Wei, Y.L. Qiu, J. Wang, J.S. Deng,
C. Wu, X. H. Han on behalf of EAFON report:
We continue to observe the optical counterpart of the Fermi GRB 130702A
( Singer et al. GCN 14967; Collazzi et al. GCN 14972 )
with Xinglong TNT telescope at 13:42:16.031 UT on 16 July, 2013
under a bad weather. 6*300 sec R-band images were obtained.
The brightness of the optical afterglow was found with a magnitude
of R~19.6 +/-0.2 mag, calibrated by USNO-B 1.0 R2 mag of the two stars
(Schulze et al. GCN 14978; Pozanenko et al. GCN 15003),
at the mean time of 14.57 days after the burst.
- 1307.5103 from 22 Jul 13
Patrick L. Kelly et al.: Evidence that Gamma-ray Burst 130702A Exploded in a Dwarf Satellite of a Massive Galaxy
GRB 130702A is a nearby long-duration gamma-ray burst (LGRB) discovered by the Fermi satellite whose associated afterglow was detected by the
Palomar Transient Factory. Subsequent photometric and spectroscopic monitoring has identified a coincident broad-lined Type Ic supernova (SN),
and nebular emission detected near the explosion site is consistent with a redshift of z=0.145. The SN-GRB exploded at an offset of ~7.6" from
the center of an inclined r=18.1 mag red disk-dominated galaxy, and ~0.6" from the center of a much fainter r=23 mag object. We obtained
Keck-II DEIMOS spectra of the two objects and find a 2{\sigma} upper limit on their line-of-sight velocity offset of ~<60 km/s. If we project
the SN-GRB coordinates onto the plane of the inclined massive disk galaxy, the explosion would have a ~61+-10 kpc offset, or ~6 times the
galaxy's half-light radius. This large estimated nuclear offset suggests that the faint source is not a star-forming region of the massive red
galaxy but is instead a dwarf galaxy. The star-formation rate of the dwarf galaxy is ~0.05 solar masses per year, and we place an upper limit
on its oxygen abundance of 12 + log(O/H) < 8.16 dex. The identification of an LGRB in a dwarf satellite of a massive, metal-rich primary galaxy
suggests that recent detections of LGRBs spatially coincident with metal-rich galaxies may be, in some cases, superpositions.
- GCN Circular #15025
L. Amati (INAF - IASF Bologna), S. Dichiara, F. Frontera, C. Guidorzi
(University of Ferrara), Luca Izzo (ICRANet, Rome), M. Della Valle
(INAF-Osservatorio Astronomico di Capodimonte) report:
A preliminary analysis of the spectral data of GRB130702A provided by the
Fermi/GBM integrated over the whole duration of the event (63.3 s from
T0-3.0 to T0 +60.3; detectors n7 and n8) suggests that the spectrum can be
fit with a simple power-law with index ~2.1+/-0.1, which is significantly
softer than the value obtained by considering only the brightest part of
the event (Collazzi & Connaughton GCN 14972; Golenetskii et al. GCN
14986). This result indicates that the spectral peak energy, Ep, is close
to the low energy threshold of the instrument or lower than it. After
fitting the spectrum with a Band function with alpha fixed at different
values and by assuming the redshift of 0.145 (e.g., Leloudas et al. GCN
14983; Mulchaey et al. GCN 14985), we find a 90% upper limit to the
cosmological rest-frame peak energy, Ep,i, of ~15-20 keV and and
isotropic-equivalent radiated energy, Eiso, of ~(6.5+/-0.10)x10^50 erg
(flat FLRW Universe with H0=70 km/s/Mpc and Omega_M = 0.3).
Based on these estimates, GRB 130702A is consistent with the Ep,i - Eiso
correlation holding for typical long GRBs and lies in the region bridging
classical cosmological long GRBs with closer and weaker GRB-SN events like
GRB060218/SN2006aj and XRF020903 (see
http://www.iasfbo.inaf.it/~amati/grb130702a.pdf).
- 1307.5851 from 24 Jul 13
Leo P. Singer et al.: Discovery and redshift of an optical afterglow in 71 square degrees iPTF13bxl and GRB 130702A
We report the discovery of the optical afterglow of the gamma-ray burst (GRB) 130702A, identified upon searching 71 square degrees surrounding
the Fermi Gamma-ray Burst Monitor (GBM) localization. Discovered and characterized by the intermediate Palomar Transient Factory (iPTF),
iPTF13bxl is the first afterglow discovered solely based on a GBM localization. Real-time image subtraction, machine learning, human vetting,
and rapid response multi-wavelength follow-up enabled us to quickly narrow a list of 27,004 optical transient candidates to a single
afterglow-like source. Detection of a new, fading X-ray source by Swift and a radio counterpart by CARMA and the VLA confirmed the association
between iPTF13bxl and GRB 130702A. Spectroscopy with the Magellan and Palomar 200-inch telescopes showed the afterglow to be at a redshift of
z=0.145, placing GRB 130702A among the lowest redshift GRBs detected to date. The prompt gamma-ray energy release and afterglow luminosity are
intermediate between typical cosmological GRBs and nearby sub-luminous events such as GRB 980425 and GRB 060218. The bright afterglow and
emerging supernova offer an opportunity for extensive panchromatic follow-up. Our discovery of iPTF13bxl demonstrates the first observational
proof-of-principle for ~10 Fermi-iPTF localizations annually. Furthermore, it represents an important step towards overcoming the challenges
inherent in uncovering faint optical counterparts to comparably localized gravitational wave events in the Advanced LIGO and Virgo era.
- CBET 3587
Schulze et al.: Supernova 2013dx = GRB 130702A
- GCN Circular #15243
G. Khorunzhev, A. Volnova, A. Pozanenko,
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
I. Bikmaev, N. Sakhibullin (KFU/AST),
I. Khamitov, H. Kirbiyik (TUG)
report:
We observed the afterglow of Fermi GRB 130702A (Singer et al., GCN
14967, Cheung et al., GCN 14971; Collazzi et al., GCN 14972), and
their progenitor Supernova SN 2013dx (Schulze et al. GCN 1994; Cenko
et al. GCN 14998) with Russian-Turkish 1.5-m telescope (RTT150,
Bakirlitepe, TUBITAK National Observatory, Turkey) on Aug., 28 starting
at UT 18:21:58. We obtained several images with exposure of 300
seconds in R band. A preliminary photometry of the GRB afterglow + SN
2013dx + host galaxy, based on two SDSS stars suggested by Schulze et
al. (GCN 14978):
T_start T0+ Filter, Exposure, OT
(UT) (mid, d) (s)
2013-08-28T18:21:58 57.74046 R 6x300 21.47+/-0.08
- 1408.6227 from 28 Aug 14
M. Kovacevic et al.: A search for Fermi bursts associated to supernovae and their frequency of occurrence
Context: Observations suggest that the major fraction of long duration gamma-ray bursts (GRBs) are connected with broad-lines supernovae Ib/c,
(SNe-Ibc). The presence of GRB-SNe is revealed by rebrightenings emerging from the optical GRB afterglow $10$--$15$ days, in the rest-frame of
the source, after the prompt GRB emission.
Aims: \textit{Fermi}-GBM has a field of view (FoV) which is about 6.5 times larger than the FoV of
\textit{Swift}, therefore we expect that a number of GRB-SN connections have been missed due to lack of optical and X-ray instruments on board
of \textit{Fermi}, which are essential to reveal SNe associated with GRBs. This fact has motivated our search in the \textit{Fermi} catalogue
for possible GRB-SN events.
Methods: The search for possible GRB-SN associations follows two requirements: (1) SN should fall inside the
\textit{Fermi}-GBM error box of the considered long GRB, and (2) this GRB should occur within $20$ days before the SN event.
Results: We have
found $5$ cases, within $z<0.2$ fulfilling the above reported requirements. One of them, GRB 130702A-SN 2013dx, was already known as GRB-SN
association. We have analyzed the remaining $4$ cases and we concluded that three of them are, very likely, just random coincidences, due to
the \textit{Fermi}-GBM large error box associated with each GRB detection. We found one GRB possibly associated with a SN 1998bw-like, GRB
120121B/SN 2012ba. Conclusions: The very low redshift of GRB 120121B/SN 2012ba ($z = 0.017$) implies a low isotropic energy of this burst
($E_{iso} = 1.39 \times 10^{48}$) erg. We then compute the rate of \textit{Fermi} low-luminosity GRBs connected with SNe to be $\rho_{0,b} \leq
770\ $Gpc$^{-3}$yr$^{-1}$. We estimate that \textit{Fermi}-GBM could detect $1$--$4$ GRBs-SNe within $z \leq 0.2$ in the next 4 years.
- 1502.04883 from 18 Feb 15
V. D'Elia et al.: SN 2013dx associated with GRB 130702A: a detailed photometric and spectroscopic monitoring and a study of the environment
Long duration gamma-ray bursts (GRBs) and broad-line, type Ic supernovae (SNe) are strongly connected. We aim at characterizing SN 2013dx,
associated with GRB 130702A, through sensitive and extensive ground-based observational campaigns in the optical-IR band.
We monitored the field of the Swift GRB 130702A (redshift z = 0.145) using the 8.2-m VLT, the 3.6-m TNG and the 0.6-m REM telescopes during the
time interval between 4 and 40 days after the burst. Photometric and spectroscopic observations revealed the presence of the associated Type Ic
SN 2013dx. Our multi-band photometry allowed the construction of a bolometric light curve.}
The bolometric light curve of SN 2013dx resembles that of 2003dh (associated with GRB 030329), but is ~10% faster and ~25% dimmer. From this we
infer a synthesized 56Ni mass of ~0.2 solar masses. The multi-epoch optical spectroscopy shows that the SN 2013dx behavior is best matched by
SN 1998bw, among the other well-known low-redshift SNe associated with GRBs and XRFs, and by SN 2010ah, an energetic Type Ic SN not associated
with any GRB. The photospheric velocity of the ejected material declines from ~2.7X10^4 km/s at 8 rest frame days from the explosion, to
~3.5X10^3 km/s at 40 days. These values are extremely close to those of SN1998bw and 2010ah. We deduce for SN 2013dx a kinetic energy of
~35X10^51 erg, and an ejected mass of ~7 solar masses. This suggests that the progenitor of SN2013dx had a mass of ~25 solar masses, i.e.,
15-20% less massive than that of SN 1998bw.
Finally, we performed a study of the SN 2013dx environment, through spectroscopy of the closeby galaxies. 9 out of the 14 inspected galaxies
lie within 0.03 in redshift from z=0.145, indicating that the host of GRB 130702A/SN 2013dx belongs to a group of galaxies, an unprecedented
finding for a GRB-associated SN and, to our knowledge, for long GRBs in general.
- 1508.00575 from 5 Aug 15
V. L. Toy et al.: Optical and near-infrared observations of SN 2013dx associated with GRB 130702A
We present optical and near-infrared light curves and optical spectra of SN 2013dx, associated with the nearby (redshift 0.145) gamma-ray burst
GRB 130702A. The prompt isotropic gamma-ray energy released from GRB 130702A is measured to be $E_{\gamma,\mathrm{iso}} = 6.4_{-1.0}^{+1.3}
\times 10^{50}$erg (1keV to 10MeV in the rest frame), placing it intermediate between low-luminosity GRBs like GRB 980425/SN 1998bw and the
broader cosmological population. We compare the observed $g^{\prime}r^{\prime}i^{\prime}z^{\prime}$ light curves of SN 2013dx to a SN 1998bw
template, finding that SN 2013dx evolves $\sim20$% faster (steeper rise time), with a comparable peak luminosity. Spectroscopically, SN 2013dx
resembles other broad-lined Type Ic supernovae, both associated with (SN 2006aj and SN 1998bw) and lacking (SN 1997ef, SN 2007I, and SN 2010ah)
gamma-ray emission, with photospheric velocities around peak of $\sim$21,000 km s$^{-1}$. We construct a quasi-bolometric
($g^{\prime}r^{\prime}i^{\prime}z^{\prime}yJH$) light curve for SN 2013dx, and, together with the photospheric velocity, we derive basic
explosion parameters using simple analytic models. We infer a $^{56}$Ni mass of $M_{\mathrm{Ni}} = 0.38\pm 0.01$M$_{\odot}$, an ejecta mass of
$M_{\mathrm{ej}} = 3.0 \pm 0.1$ M$_{\odot}$, and a kinetic energy of $E_{\mathrm{K}} = (8.2 \pm 0.40) \times 10^{51}$erg (statistical
uncertainties only), consistent with previous GRB-associated SNe. When considering the ensemble population of GRB-associated SNe, we find no
correlation between the mass of synthesized $^{56}$Ni and high-energy properties, despite clear predictions from numerical simulations that
$M_{\mathrm{Ni}}$ should correlate with the degree of asymmetry. On the other hand, $M_{\mathrm{Ni}}$ clearly correlates with the kinetic
energy of the supernova ejecta across a wide range of core-collapse events.
Previous IAU Circulars 
