GRB 130514A
GCN Circular 14632
Subject
GRB 130514A: Swift detection of a burst
Date
2013-05-14T07:29:58Z (12 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
E. Sonbas (NASA/GSFC/Adiyaman Univ.), V. D'Elia (ASDC),
P. A. Evans (U Leicester), K. L. Page (U Leicester) and
D. Palmer (LANL), R. L. C. Starling (U Leicester) report on behalf of the Swift Team:
At 07:13:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130514A (trigger=555821). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 296.274, -7.956 which is
RA(J2000) = 19h 45m 06s
Dec(J2000) = -07d 57' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex
structure with a duration of at least 180 sec. The peak count rate
was ~3200 counts/sec (15-350 keV), at ~10 sec after the trigger.
The XRT began observing the field at 07:15:09.9 UT, 88.8 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 296.28055, -7.97808 which
is equivalent to:
RA(J2000) = 19h 45m 07.33s
Dec(J2000) = -07d 58' 41.1"
with an uncertainty of 4.1 arcseconds (radius, 90% containment). This
location is 82 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. We
cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 7.65
x 10^20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 5.83e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 97 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.23.
Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com).
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.)
GCN Circular 14633
Subject
GRB 130514A: P60 Observations
Date
2013-05-14T08:39:21Z (12 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech) reports on behalf of a larger collaboration:
The Palomar 60-inch telescope automatically responded to GRB 130427A
(Sonbas et al., GCN 14632) and slewed to the position as soon as the
source became observable a few minutes after the GRB alert. A series of
r, i, and z-band exposures was taken at very high airmass (~4) starting
at 07:25:33 UT, 11.85 minutes after the BAT trigger.
The field is crowded, and contains a small globular cluster (GCl 114)
centered at RA=19:45:14.40 Dec=-08:00:26.0 (J2000), 2.5 arcminutes from
the GRB.
We do not detect any source at a position coincident with the XRT
position in individual images. A stack of the first five r-band images
(spanning from 12-27 minutes after the GRB) shows no clear object at
this position to a limiting magnitude of R > 19.6 mag (3 sigma),
although there is a marginal detection of a source inside the error
circle slightly below this level, centered at RA=19:45:07.27,
Dec=-07:58:42.3 (J2000, +/-1.5 arcsec). It is also apparent in similar
r- and z-band stacks, and so is probably real. The source may also be
marginally present in the DSS imaging, although it is not in the USNO
B1.0 catalog.
The association of the GRB with the globular cluster (or the optical
source) is unclear; this could be an unusual Galactic event or a chance
alignment of an ordinary extragalactic GRB (with a faint optical
afterglow) with these objects. Further observations are encouraged.
GCN Circular 14634
Subject
GRB 130514A: GROND optical-NIR afterglow discovery and photo-z
Date
2013-05-14T08:40:11Z (12 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
S. Schmidl, D. A. Kann (both TLS Tautenburg) and J. Greiner (MPE Garching)
report on behalf of the GROND team:
We observed the field GRB 130514A (Swift trigger 555821; E. Sonbas et al.,
GCN 14632) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla
Observatory (Chile).
Observations started at 07:15:31 UT on May 14th, 2 minutes after the SWIFT
BAT trigger. They were performed at an average seeing of 1" and at an
average airmass of 1.18.
Inside the 2".6 refined XRT error circle, we detect a source not visible
in the DSS or SDSS in all 7 bands. The GROND position for this source is:
RA (J2000) = 19:45:07.90
Dec.(J2000) = -07:58:34.4
with an uncertainty of 0".3.
Based on the first 4 min of total exposure we estimate preliminary
magnitudes (all in AB system) of
g' = 22.17 +- 0.09,
r' = 19.98 +- 0.01,
i' = 19.18 +- 0.02,
J = 17.87 +- 0.03,
H = 17.26 +- 0.03 and
K = 16.81 +- 0.03
We propose this source to be the afterglow of GRB 130514A. Additional
evidence is the power-law shape of the SED.
The source shows a strong g'-band dropout, we derive a photometric
redshift of z = 3.6 +/- 0.2, with an additional small line-of-sight
extinction by SMC dust.
Given magnitudes are calibrated against SDSS as well as 2MASS field stars
and are not corrected for the expected Galactic foreground extinction
corresponding to a reddening of E_(B-V)=0.23 mag in the direction of the
burst (Schlegel et al. 1998).
GCN Circular 14636
Subject
GRB 130514A: Swift-BAT refined analysis
Date
2013-05-14T12:33:26Z (12 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS),
M. Stamatikos (OSU), J. Tueller (GSFC)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+723 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 130514A (trigger #555821)
(Sonbas, et al., GCN Circ. 14632). The BAT ground-calculated position is
RA, Dec = 296.278, -7.974 deg, which is
RA(J2000) = 19h 45m 06.8s
Dec(J2000) = -07d 58' 26.1"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.
The mask-weighted light curve shows two peaks, the first starting at ~T-20 sec,
peaking at ~T+12 sec, and returning almost to baseline at ~T+80 sec.
The second peak starts at ~T+80 sec, peaks at ~T+115 sec, and ends at ~T+380 sec.
T90 (15-350 keV) is 204 +- 13 sec (estimated error including systematics).
The time-averaged spectrum from T-7.09 to T+258.01 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.80 +- 0.05. The fluence in the 15-150 keV band is 9.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+13.42 sec in the 15-150 keV band
is 2.8 +- 0.3 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/555821/BA/
GCN Circular 14637
Subject
GRB 130514A: Enhanced Swift-XRT position
Date
2013-05-14T12:33:41Z (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 1035 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 130514A, 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 = 296.28288, -7.97592 which is equivalent
to:
RA (J2000): 19h 45m 7.89s
Dec (J2000): -07d 58' 33.3"
with an uncertainty of 1.9 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 14640
Subject
GRB 130514A: Swift/UVOT Upper Limits
Date
2013-05-14T17:28:08Z (12 years ago)
From
Frank Marshall at GSFC <femarsha@khamseen.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC) and E. Sonbas (NASA/GSFC/Adiyaman Univ.)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 130514A
97 s after the BAT trigger (Sonbas et al., GCN Circ. 14632).
No optical afterglow consistent with the optical position
from GROND (Schmidl et al. GCN Circ. 14634)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 97 247 147 >21.3
u_FC 310 560 246 >20.4
white 97 960 281 >21.5
v 639 2529 56 >18.7
b 565 757 39 >19.1
u 310 732 265 >20.5
w1 688 708 19 >19.1
w2 2487 2507 19 >19.5
The magnitudes in the table are not corrected for the
Galactic extinction due to the reddening of E(B-V) = 0.23
in the direction of the burst (Schlegel et al. 1998).
GCN Circular 14643
Subject
GRB 130514A: RATIR Optical and NIR Observations
Date
2013-05-14T18:13:06Z (12 years ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Nat Butler (ASU), 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�� A. de Diego (UNAM), Leonid Georgiev (UNAM),
Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC),
and Harvey Moseley (GSFC) report:
We observed the field of GRB 130514A (Sonbas et al., GCN 14632) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional on
Sierra San Pedro M��rtir from 2013/05 14.30 to 2013/05 14.46 UTC (4.7 minutes
to 3.90 hours after the BAT trigger), obtaining a total of 2.49 hours
exposure in the r' and i' bands and 1.04 hours exposure in the Z,
Y, J, and H bands.
For a source within the Swift-XRT error circle, in comparison with USNO-B1
and 2MASS, we obtain the following upper limits (3-sigma):
r' > 23.51
i' > 23.39
Z > 22.07
Y > 21.62
J > 21.43
H > 21.13
These magnitudes are in the AB system and not corrected for Galactic
extinction in the direction of the GRB.
Schmidl et al. (GCN Circular 14634) report a source with r = 20.0 and i =
19.2 in images taken from 2 to 6 minutes after the BAT trigger. Perley
(GCN Circular 14633) reports a marginal detection in r and z in images
taken from 12 to 27 minutes after the BAT trigger. We began exposing on
this field less than 5 minutes after the BAT trigger, but due to the
high airmass of almost 5 and poor transparency on the south-eastern
horizon, our first useful images are not until about 17 minutes after
the trigger. The evolution of our 3-sigma limits is:
i' > 21.72 at 0.49 hours after the trigger
i' > 22.48 at 1.14 hours
i' > 23.00 at 1.59 hours
i' > 23.17 at 2.02 hours
i' > 23.24 at 2.60 hours
i' > 23.30 at 3.34 hours
i' > 23.39 at 3.90 hours
If we extrapolate the Schmidl et al. measurement of i = 19.2 at 4 minutes
according to t^-1, we would expect to have detected their source in our
observations out to 2 hours. That we did not suggests that light curve
fell faster than this. We note that quick-look light curve for Swift-XRT
falls by almost three orders of magnitude between about 3 minutes and 20
minutes, which may be consistent with a rapid optical decay.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
[GCN OPS NOTE(14may13): Per author's request,"Kann et al" was changed
to "Schmidl et al", and the "approx equal" ISO-char symbols were replaced
with simple equal signs (=).]
GCN Circular 14648
Subject
GRB 130514A: Skynet/PROMPT/DSO Detections
Date
2013-05-15T00:28:06Z (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, A. Smith, D. Caton, L.
Hawkins, T. Berger, H. T. Cromartie, R. Egger, A. Foster, N. Frank, K.
Ivarsen, M. Maples, J. Moore, M. Nysewander, E. Speckhard, and J. A.
Crain report:
Skynet observed the Swift/XRT localization of GRB 130515A (Sonbas et
al., GCN 14632, Swift trigger #555821) with four 16" telescopes of the
PROMPT array at CTIO, Chile and with the 14" telescope at the
Appalachian State University Dark Sky Observatory (DSO) in Pisgah
National Forest, North Carolina, starting at 2013-05-14, 07:14:32 UT,
and continuing until 10:24 UT (t=51s-3.2h post-trigger). It took ~400
exposures, ranging from 5s at early times to 160s at late times,
simultaneously in each of the BVRI bands. We performed photometry on
each exposure, calibrated to seven USNO-B1/NOMAD stars in the field.
We detect a fading afterglow at t=2-12m in the I band in unstacked
images at the position reported by the GROND team (Schmidl, Kann &
Greiner, GCN 14640), with I~17.4 at t=2m, fading with an approximate
temporal index alpha~-1.2. In stacked images, we obtain weak detections
in R band at t=2.27m and 51m, and in V band at t=3.75m; both the R and
the V band detections are ~1mag fainter than the I band light curve. In
B band, we obtain three weak detections from t=5m to 15m, all ~0.6mag
fainter than the I band light curve.
A preliminary plot of our data is at:
http://skynet.unc.edu/grb/grb130514a.png
No further Skynet observations are scheduled.
GCN Circular 14649
Subject
GRB 130514A: Swift-XRT refined Analysis
Date
2013-05-15T01:30:03Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
B.P. Gompertz (U. Leicester), A. Maselli (INAF-IASFPA), V. Mangano
(INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows (PSU), J.A. Kennea
(PSU), M.C. Stroh (PSU), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester) and E. Sonbas report on behalf of the Swift-XRT team:
We have analysed 8.5 ks of XRT data for GRB 130514A (Sonbas et al. GCN
Circ. 14632), from 95 s to 37.1 ks after the BAT trigger. The data
comprise 405 s 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 14637).
The late-time light curve (from T0+5.8 ks) can be modelled with a
power-law decay with a decay index of alpha=1.15 (+0.13, -0.12).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.82 (+/-0.03). The
best-fitting absorption column is 3.14 (+0.13, -0.12) x 10^21 cm^-2,
in excess of the Galactic value of 7.6 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.99 (+0.20, -0.19)
and a best-fitting absorption column of 1.4 (+/-0.5) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.7 x 10^-11 (5.0 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.4 (+/-0.5) x 10^21 cm^-2
Galactic foreground: 7.6 x 10^20 cm^-2
Excess significance: 2.1 sigma
Photon index: 1.99 (+0.20, -0.19)
If the light curve continues to decay with a power-law decay index of
1.15, the count rate at T+24 hours will be 9.1 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.4 x
10^-13 (4.5 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00555821.
This circular is an official product of the Swift-XRT team.
GCN Circular 14702
Subject
GRB 130514A: Konus-Wind and Swift/BAT joint spectral analysis
Date
2013-05-24T20:24:57Z (12 years ago)
From
Valentin Pal'shin at Ioffe Inst <val@mail.ioffe.ru>
V. Pal'shin, S. Golenetskii, R.Aptekar, E. Mazets, D. Frederiks, D.
Svinkin, M. Ulanov, and T. Cline on behalf of the Konus-Wind team,
T. Sakamoto (AGU), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC), D. Palmer (LANL), M.
Stamatikos (OSU) and T. Ukwatta (GWU)
report:
We performed the Konus-Wind and the Swift/BAT joint spectral analysis of
GRB 130514A (Swift/BAT trigger #555821: Sonbas et al., GCN Circ. 14632,
Ukwatta et al. GCN Circ. 14636). Since the Konus-Wind observed this GRB
in the waiting mode, we only have 3 channel spectral data for the
Konus-Wind which cover the energy range from 20 keV to 1.2 MeV. The
joint spectral analysis of the Konus-Wind and the Swift/BAT data allows
us to derive the broad-band spectral parameters of this burst.
The time interval of the spectral data for each instrument is chosen
from T0(BAT)-5.1 to T0(BAT)+153.9 s where T0(BAT) is the trigger time of
BAT at 07:13:41 UTC. This interval comprises whole burst as observed by
Konus-Wind and contains 87% of the total fluence in the 15-150 keV as
observed by BAT (Ukwatta et al. GCN Circ. 14636).
The energy ranges which we used in the joint spectral analysis are
20-1200 keV and 14-150 keV for the Konus-Wind and the Swift/BAT
respectively. The spectral data of two instruments are fitted with the
spectral model multiplied by the constant factor to take into account
the systematic effective area uncertainties in the response matrices of
each instrument.
The spectrum is well fitted with a power-law with exponential cutoff
model: dN/dE ~ E^{alpha}*exp(-(2+alpha)*E/Epeak). No systematic residual
from the best fit model is seen in the spectral data of each instrument.
The BAT constant factor is 0.83(-0.08,+0.10) (the KW constant factor is
fixed to 1). The best fit spectral parameters are: alpha =
-1.44(-0.14,+0.17) and Epeak = 110(-21,+42) keV (chi2/dof = 41.9/57).
The best fit spectral parameters for the GRB (Band) model fixing beta =
-2.5 are: alpha = -1.44(-0.15,+0.17), and Epeak = 108(-21,+45) keV
(chi2/dof = 43.6/57). The energy fluence in the 15-1200 keV band
calculated by a power-law with exponential cutoff model for this 159 s
interval is 1.40(-0.16,+0.21)x10^-5 erg/cm2.
Assuming a photo-z of 3.6 (Schmidl, Kann, and Greiner GCN Circ. 14634)
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 =
4.95(-0.67,+0.85)x10^53 erg in 1 keV to 10 MeV at the GRB rest frame
extrapolating the best exponential cutoff function fit.
All the quoted errors are at the 90% confidence level.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB130514A/