GRB 080413A
GCN Circular 7597
Subject
GRB 080413A: REM detection of the NIR Afterglow
Date
2008-04-13T09:06:15Z (17 years ago)
From
Angelo Antonelli at Obs. Astro. di Roma <a.antonelli@oa-roma.inaf.it>
L.A. Antonelli, P. D'Avanzo, D. Malesani, S. Covino, D. Fugazza, L.
Calzoletti, S. Campana, G. Chincarini, M.L. Conciatore, S. Cutini, V.
D'Elia, F. D'Alessio, F. Fiore, P. Goldoni, D. Guetta, C. Guidorzi,
G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E.J.A. Meurs, L.
Nicastro, E. Palazzi, E. Pian, F. Piranomonte, S. Piranomonte, L.
Stella, G. Stratta, G. Tagliaferri, G. Tosti, V. Testa, S.D. Vergani,
and F. Vitali, report on behalf of the REM team:
The robotic 60-cm REM telescope located at La Silla (Chile) observed
automatically the field of the GRB 080413A (Beardmore et al., GCN
7594) starting about 1.3 hours after the burst due to object
visibility constraints.
Observation started as soon as the object is risen so the Airmass was
large.
A preliminary investigation of our earliest images (R,z,J,H,K) showed
that the candidate optical counterpart (Rykoff et al. GCN 7593,
Beardmore et al., GCN 7594, Klotz et al., GCN 7595) is observed in
all bands. At the beginning of REM observation, the object had a H
mag of about H=15.2 calibrated against 2MASS and not corrected for
galactic extinction.
This message may be cited.
GCN Circular 7602
Subject
GRB 080413A: VLT/UVES redshift
Date
2008-04-13T12:10:21Z (17 years ago)
From
Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr <cthoene@astro.ku.dk>
Christina C. Thoene, Daniele Malesani, Paul M. Vreeswijk, Johan P. U.
Fynbo (DARK/NBI), Pall Jakobsson (Univ. of Hertfordshire), Cedric Ledoux
and Alain Smette (ESO) report on behalf of a larger collaboration:
We observed the afterglow of GRB 080413A (GCN 7593, Rykoff & Rujopakarn;
GCN 7594, Stamatikos et al.) on Apr. 13 starting UT 06:36 with UVES at the
VLT. Spectra of 2700 s with low S/N were acquired in the DIC 2R and
2B settings covering the wavelength range between 3250 and 9000 AA.
We detect several narrow absorption features including SII, Si II, CII,
Fe II, AlII, C IV, Si IV as well as broad Lyman alpha absorption at the
highest redshift system which has z=2.433 and is very likely the redshift
of GRB 080413A.
We thank the Paranal staff for executing the observations, in particular
Swetlana Hubrig and Jose Cortes.
GCN Circular 7603
Subject
GRB 080413A Bootes observation
Date
2008-04-13T12:50:49Z (17 years ago)
From
Petr Kubanek at AIO <petr@lascaux.asu.cas.cz>
P. Kubanek, M. Jelinek, J. Gorosabel, A. J. Castro-Tirado (IAA-CSIC
Granada), L. Sabau-Graziati (INTA Madrid), A. de Ugarte Postigo (ESO
Santiago), R. Hudec (ASU-CAS Ondrejov), P. Perez-Gonzalez and J.
Zamorano (UCM Madrid) report on behalf of a larger collaboration:
The BOOTES-1 0.3m telescope in South Spain observed GRB 080413A,
starting at 02:55:20 UT (46 sec after receiving trigger, 1 minute after
GRB). A sequence of preprogrammed 6 sec, 20 and 60 sec exposures was
obtained. The optical counterpart reported by Rykoff at al. (GCN
7593) is clearly detected on the initial exposures.
Further data were obtained at the 2.5m NOTin La Palma under non-optimal
conditions.
GCN Circular 7604
Subject
GRB 080413A, Swift-BAT refined analysis
Date
2008-04-13T15:58:16Z (17 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
J. Tueller (GSFC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), J. Cummings (GSFC/UMBC), E. Fenimore (LANL),
N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
K. McLean (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+454 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080413A (trigger #309096)
(Beardmore, et al., GCN Circ. 7594). The BAT ground-calculated position is
RA, Dec = 287.301, -27.677 deg, which is
RA(J2000) = 19h 09m 12.1s
Dec(J2000) = -27d 40' 36.8"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 81%.
The mask-weighted light curve shows four peaks. The first starting at T-0.1 sec,
peaking at T+2.0 sec. The second peak overlaps with the first and peaks
at ~T+7 sec. The third and fourth peaks are well separated with peaks
at T+16 and T+47 sec, repsectively. The lightcurve returns to baseline
at ~T+80 sec. T90 (15-350 keV) is 46 +- 1 sec (estimated error
including systematics).
The time-averaged spectrum from T-0.1 to T+50.3 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.57 +- 0.06. The fluence in the 15-150 keV band is 3.5 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.64 sec in the 15-150 keV band
is 5.6 +- 0.2 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/309096/BA/
GCN Circular 7605
Subject
GRB 080413A: Swift-XRT refined analysis
Date
2008-04-13T16:39:02Z (17 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans, K.L. Page, A.P. Beardmore, R.L.C. Starling (U. Leicester)
and F.E. Marshall (NASA/GSFC) report on behalf of the Swift-XRT team:
We have analysed 5.2 ks of Swift XRT data for GRB 080413A (Beardmore et
al. GCN Circ. 7594), from T0+67 s to T0+21000 s. The first 186 s of data
were obtained in Windowed Timing (WT mode); the remainder in Photon
Counting mode. The best XRT position for this object is the
UVOT-enhanced position given in Osborne et al. (GCN Circ. 7596).
The X-ray light curve is well fitted by a power-law decay, with an
initial decay slope of 2.87 (+/- 0.19) up to T0+175 (+23/-16) s, at
which point the decay shallows to a slope of 1.10 (+0.06/-0.07).
A spectrum obtained from all of the WT mode data can be modelled with an
absorbed power-law with a photon index gamma=3.12 (+0.16/-0.15). A
redshifted absorbing column of 1.53 (+0.43/-0.38) x 10^22 cm^-2, at a
redshift of z=2.433 (Thoene et al. GCN Circ 7602) is necessary in
addition to the Galactic column of 8.71 x 10^20 cm^-2 (Kalberla et al.
2005). The observed (unabsorbed) 0.3-10 keV flux in this spectrum is
4.1 x 10^-10 (1.71 x 10^-9) erg cm^-2 s^-1.
If the source continues to decay at the present rate, we predict a count
rate of 3.51 x 10^-3 count/sec at T0+24 hours, which correponds to a
0.3-10 keV observed (unabsorbed) flux of 9.54 x 10^-14 (2.72 x 10^-13)
erg cms^-2 s^-1.
This circular is an official product of the Swift-XRT team.
GCN Circular 7607
Subject
GRB080413A: Swift/UVOT observations
Date
2008-04-13T17:49:17Z (17 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates and F. E. Marshall report on behalf of the Swift/UVOT team.
The Swift/UVOT observed the field of GRB 080413A starting at 77s after
the BAT
trigger (Beardmore et al., GCN 7594). We detect the afterglow in
white,v,b and
u filters at the position:
RA(J2000.0) = 19:09:11.76
DEC(J2000.0) = -27:40:40.27
with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence).
This position is
consistent with the enhanced XRT position and the position reported by
ROSTE-III
(Rykoff et al., GCN 7593).
The magnitudes and 3 sigma upper limits are reported below:
Filter T_Mid(s) Expo(s) Magnitude/3sigUL
-----------------------------------------------------
White 126 98 15.37 +/- 0.01
White 5478 197 19.74 +/- 0.17
v 268 169 15.08 +/- 0.03
v 5888 197 19.16 +/- 0.51
b 5273 197 19.33 +/- 0.21
u 5068 197 19.05 +/- 0.22
w1 4863 197 >19.55
m2 4658 197 >19.48
w2 5684 197 >19.57
-----------------------------------------------------
The above magnitudes are not corrected for the Galactic extinction
corresponding to a
reddening of E_{B-V} = 0.16 mag (Schlegel et al., 1998, ApJS, 500, 525).
The photometry
is on the UVOT flight system described in Poole et al. (2008,MNRAS,383,627).
GCN Circular 7609
Subject
GRB 080413a, SMARTS optical/IR afterglow observations
Date
2008-04-13T19:22:38Z (17 years ago)
From
Bethany Cobb at Yale U <cobb@astro.yale.edu>
B. E. Cobb (Yale), part of the larger SMARTS consortium, reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 080413a
(GCN 7594, Beardmore et al.), starting at 2008-04-13 05:48 UT,
which is ~2.9 hours post-burst. Several dithered images were obtained
in each filter, with total summed exposure times of 180s in each of
BRIYJK and 120s in each of H and V.
The GRB afterglow (GCN 7593 Rykoff & Rujopakarn; GCN 7594,
Beardmore et al.) is detected in all our images. At
a mid-exposure time of 2008-04-13 06:02 (~3.1 hours post-burst)
the afterglow has the following magnitudes (which have not been
corrected for Galactic reddening):
B= 20.88 +/- 0.10
V= 20.25 +/- 0.11
R= 19.25 +/- 0.05
I= 18.84 +/- 0.06
J= 18.23 +/- 0.23
H= 17.05 +/- 0.15
K= 16.19 +/- 0.12
Optical photometry is calibrated against Landolt standard stars
and IR photometry is calibrated against 2MASS stars in the field.
Between 3.1 and 5.1 hours post burst, the afterglow decays
by ~0.75 magnitudes, indicating an approximate decay rate of alpha = -1.4
(where afterglow flux is proportional to t^alpha).
GCN Circular 7614
Subject
VLA radio observations of GRB 080413A
Date
2008-04-14T14:33:02Z (17 years ago)
From
Poonam Chandra at U Virginia/NRAO <pc8s@virginia.edu>
Poonam Chandra (NRAO/UVA) and Dale A. Frail (NRAO) report on behalf
of the Caltech-NRAO-Carnegie GRB Collaboration:
"We used the Very Large Array to observe the field of view toward GRB
080413A (GCN 7594) at a frequency of 8.46 GHz at 2008 April 14.53 UT.
We do not detect the GRB afterglow at the ROTSE optical position (GCN
7593).
The flux density at the GRB afterglow position is -61 +/- 49 uJy.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 7616
Subject
GRB 080413A: Gemini-South Spectroscopy
Date
2008-04-14T17:27:38Z (17 years ago)
From
Antonino Cucchiara at PSU <cucchiara@astro.psu.edu>
A. Cucchiara and D. B. Fox (Penn State) with S. B. Cenko (Caltech),
report on behalf of a larger collaboration:
"Starting on 2008 April 13.27 UT we observed GRB 080413A (GCN 7593 and
7594) with the GMOS spectrograph on the Gemini South telescope. We
obtained 2x1200-sec spectra in the wavelength range 3900-8000A. The
resolution of our spectrum is 5.2 Ang/pixel (R ~1200 at 6000A). We
clearly observe several metal absorption features corresponding to the
SiIV (1393,1402 A), CIV (1548, 1550A), SiII (1526A), and AlII (1670A)
transitions. A Lyman break is also present at the blue edge of our
spectra (~ 4170A). These identifications are consistent with a host
galaxy redshift of z = 2.43, confirming the result reported from VLT
observations by Thoene et al.(GCN 7602)."
GCN Circular 7622
Subject
GRB 080413A: MOA-II optical afterglow observations
Date
2008-04-15T23:48:14Z (17 years ago)
From
Nobuyuki Kawai at Tokyo Tech <nkawai@hp.phys.titech.ac.jp>
A. Fukui, Y. Itow, T. Sumi (STE Lab, Nagoya Univ.), and P. Tristram
(Canterbury Univ.) on behalf of the MOA Collabration (Bond et
al. 2001, Sumi et al. 2003) report:
We observed the optical afterglow of GRB080413A (GCN 7593, Rykoff &
Rujopakarn; GCN 7594, Beardmore et al.) on Apr. 13 between
12:29:16.4 UTC and 14:13:06.6 UTC, corresponding to about 9.5-11 h
after the burst, with the 1.8m MOA-II telescope at Mt. John
observatory in New Zealand. Total 5 images were obtained with a wide-
band Red filter (center wavelength ~ 750nm and FWHM ~ 250nm) and we
could identify the faint afterglow within the error circle (<0.5").
The identified R.A. Dec. are 19:09:11.752 -27:40:39.99 with an
uncertainty of 0.14" (radius, 1sigma) and following are the
photometric results: I magnitude = 20.24 +/- 0.32 at the mid-exposure
time of 2008-04-13 12:29:16.4 UTC, 20.09 +/- 0.19 at 12:51:10.7 UTC,
21.40 +/- 0.61 at 13:03:0.1 UTC, 20.05 +/- 0.17 at 13:42:47.0 UTC,
and 20.75 +/- 0.25 at 14:13:06.6 UTC. These photometry were done by
using the IRAF and calibrated against the USNO-B1.0 catalog stars,
and not corrected for the Galactic extinction.
[GCN OPS NOTE(18apr08): By the moderator's choice, the "GCN 7594, Stamatikos et al"
wash changed to "GCN 7594, Beardmore et al". Ack to F. Marshall.]
GCN Circular 7624
Subject
GRB 080413A: Suzaku WAM observation of the prompt emission
Date
2008-04-16T16:11:23Z (17 years ago)
From
Kazutaka Yamaoka at Aoyama Gakuin U <yamaoka@phys.aoyama.ac.jp>
T. Enoto (Univ. of Tokyo), Y.E. Nakagawa, T. Tamagawa (RIKEN),
T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata
(Hiroshima U.), K. Yamaoka, S. Sugita (Aoyama Gakuin U.), M. Tashiro,
Y. Terada, Y. Urata, A. Endo, K. Onda, N. Kodaka, K. Morigami (Saitama U.),
K. Nakazawa, K. Makishima (Univ. of Tokyo), E. Sonoda, M. Yamauchi,
H. Tanaka, R. Hara (Univ. of Miyazaki), M. Ohno, M. Kokubun,
M. Suzuki, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.),
on behalf of the Suzaku WAM team, report:
The long GRB 080413A (Swift/BAT trigger #309096 ; Beardmore et al., GCN
7594) was detected by the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 02:54:18.648 UT (=T0).
The observed light curve shows a clear double-peaked structure
at T0+2s and T0+16s, and possible weak peak at T0+45s,
with a total duration (T90) of about 19 seconds.
The fluence in 150 - 1000 keV was (2.2 +/- 0.5) x 10^-6 erg/cm^2.
The 1-s peak flux measured from T0+2s was 0.77 +/- 0.19 photons/cm^2/s
in the same energy range.
Preliminary result shows that the time-averaged spectrum from T0+0s to T0+20s
is fitted by a single power-law with a photon index of
2.4 +/- 0.4 (chi^2/d.o.f = 15.1/10) in 150 - 1000 keV.
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.
The light curves with 1-sec time resolution for this burst are now available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html
GCN Circular 7625
Subject
GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations
Date
2008-04-16T17:23:09Z (17 years ago)
From
Andreja Gomboc at LT,ARI,Liverpool JMU <ag@astro.livjm.ac.uk>
A. Gomboc (Ljubljana), C. Guidorzi (U. Bicocca/INAF-OAB), A. Melandri, I.A.
Steele, C.G. Mundell, D.F. Bersier, M.F. Bode, M.J. Burgdorf, S.N. Fraser,
S. Kobayashi, C.J. Mottram, R.J. Smith (Liverpool JMU), P. O'Brien, N.
Bannister, N. Tanvir (U. Leicester) report on behalf of larger GRB
collaboration:
The Liverpool Telescope observed the field of GRB 080413A (trigger=309096,
Beardmore et al. GCN 7594) under poor weather conditions starting 2-hr after
the trigger. Observations continued with the Faulkes Telescope South.
In our coadded frames we do not detect any source at the position of the
optical afterglow (Beardmore et al. GCN 7594, Rykoff & Rujopakarn GCN
7593) down to the limiting magnitudes reported below.
Telescope Filter Tstart(hr) Tstop(hr) Exposure(s) M_lim
----------------------------------------------------------------------
Liverpool R 2.0 2.5 760 15.7
Faulkes South R 12.2 12.2 30 19.2
I 12.2 13.1 2080 21.7
----------------------------------------------------------------------
Magnitudes were calibrated with respect to USNOB1 R2 and I.
GCN Circular 7630
Subject
GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
Date
2008-04-18T21:50:05Z (17 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori.sakamoto-1@nasa.gov>
M. Ohno, M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA)
K. Yamaoka, S. Sugita (Aoyama Gakuin U.),
T. Enoto (Univ. of Tokyo), Y.E. Nakagawa, T. Tamagawa (RIKEN),
T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata
(Hiroshima U.), M. Tashiro,
Y. Terada, Y. Urata, A. Endo, K. Onda, N. Kodaka, K. Morigami (Saitama U.),
K. Nakazawa, K. Makishima (Univ. of Tokyo), E. Sonoda, M. Yamauchi,
H. Tanaka, R. Hara (Univ. of Miyazaki), , S. Hong (Nihon U.),
on behalf of the Suzaku WAM team, report:
J. Tueller (GSFC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), J. Cummings (GSFC/UMBC), E. Fenimore (LANL),
N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
K. McLean (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
report:
We performed the Suzaku/WAM and Swift/BAT joint fit spectral
analysis of GRB 080413A (Swift/BAT trigger #309096; Beardmore et al.,
GCN 7594). The time interval of the spectral data for each
instrument is chosen from T0(WAM)-1 to T0(WAM)+22 sec where
T0(WAM) is the trigger time of WAM at 02:54:18.648 UTC.
This time interval includes the initial two peaks, but not
the relatively soft third peak around T0(WAM)+45 sec which
is clearly visible in the BAT data (Tueller et al., GCN 7604).
The energy ranges which we used in the joint spectral analysis
are 13-150 keV and 150-1000 keV for Swift/BAT and Suzaku/WAM
respectively. The spectral data of two instruments are fit
with the spectral model multiplied by the constant factor to
take into account the systematic uncertainties in the response
matrices of each instrument.
The spectrum is well fit with a power-law with exponential cutoff
model (dN/dE ~ E^{alpha} * exp(-(2+alpha)*E/Epeak)). The constant
factors of each instrument agree within 20%. No systematic residual
from the best fit model is seen in the spectral data of each instrument.
The best fit spectral parameters are: alpha = -1.2 +- 0.1 and
Epeak = 170 (-40/+80) keV (chi2/dof = 75/73). The energy fluence
in the 15-1000 keV band calculated by a power-law with exponential
cutoff model for this 23 sec interval is 4.8 (-1.2/+0.4) x 10^-6 erg/cm2
(assuming the constant factor of the BAT is fixed to 1).
Assuming z = 2.433 (Thoene et al., GCN 7602) 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 ~8x10^52 erg in 1 keV to 10 MeV at the GRB rest frame.
All the quoted errors are at the 90% confidence level.