GRB 080319A
GCN Circular 7426
Subject
GRB 080319A: Swift detection of a burst
Date
2008-03-19T06:18:20Z (17 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
C. Pagani (PSU), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
C. B. Markwardt (CRESST/GSFC/UMD), D. M. Palmer (LANL),
J. L. Racusin (PSU) and M. Stamatikos (NASA/ORAU) report on behalf of
the Swift Team:
At 05:45:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080319A (trigger=306754). The Swift slew to the burst was
delayed because of an earth constraint. The BAT on-board calculated
location is RA, Dec 206.354, +44.079 which is
RA(J2000) = 13h 45m 25s
Dec(J2000) = +44d 04' 44"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multiple peaks
with a duration of about 40 sec. The peak count rate
was ~800 counts/sec (15-350 keV), at ~10 sec after the trigger.
The XRT began observing the field at 05:54:59.4 UT, 557.4 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 206.33306, 44.08029
which is equivalent to:
RA(J2000) = 13h 45m 19.94s
Dec(J2000) = +44d 04' 49.1"
with an uncertainty of 2.6 arcseconds (radius, 90% containment). This
location is 54 arcseconds from the BAT onboard position, within the BAT
error circle.
A power-law fit to a spectrum formed from promptly downlinked event
data does not constrain the column density, so we cannot provide limits
on the redshift using spectroscopy and the relation from Grupe et al.
(2007). A summary of the promptly downlinked data is given at
http://www.swift.ac.uk/sper/306754/.
UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm) filter starting 562 seconds after the BAT trigger. A
possible low-significance afterglow candidate has been found at the
XRT position in the initial data products. The magnitude is white
= 21.7 mag. No correction has been made for the expected extinction
corresponding to E(B-V) of 0.01.
Burst Advocate for this burst is C. Pagani (pagani AT astro.psu.edu).
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 7429
Subject
GRB080319A: P60 Optical Afterglow Observations
Date
2008-03-19T06:49:33Z (17 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko reports on behalf of a larger collaboration:
We have imaged the field of GRB080319A (Pagani et al., GCN 7426) with the
automated Palomar 60-inch telescope beginning approximately 2.5 minutes
after the burst. Inside the XRT error circle (and consistent with the
UVOT candidate) we find a single faint, fading point source at coordinates
(J2000.0):
RA: 13:45:20.01
Dec: +44:04:48.6
with an estimated uncertainty of ~ 0.3". Using the USNO-B catalog as a
reference, we measure a magnitude of R ~ 20.25 +/- 0.2 in our initial
R-band image.
Further observations are planned.
GCN Circular 7436
Subject
GRB 080319A: optical observations at the NOT
Date
2008-03-19T11:06:34Z (17 years ago)
From
Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center <malesani@astro.ku.dk>
D. Malesani, J. P. U. Fynbo, P. M. Vreeswijk (DARK), C. Villforth (NOT),
report on behalf of a larger collaboration:
We observed the field of GRB 080319A (Pagani et al., GCN 7426) with the
Nordic Optical Telescope, starting on 2008 March 19.265 UT. Exposures in
the R and I bands were secured.
We detect the afterglow reported by Cenko (GCN 7429). Compared to the
USNO-B1 star 1340-0249427 at RA = 13:45:26.457, Dec = +44:04:45.56 (R1 =
15.79), we measure R = 21.03 +- 0.09 on Mar 19.27088 UT (44.4 min after
the GRB).
A finding chart is posted at:
http://www.astro.ku.dk/~malesani/GRB/080319A/080319A_finder.jpg
We acknowledge excellent support from the NOT observing staff.
GCN Circular 7440
Subject
GRB 080319A: REM observations
Date
2008-03-19T11:59:06Z (17 years ago)
From
Stefano Covino at Brera Astronomical Observatory <stefano.covino@gmail.com>
S. Covino, P. D'Avanzo, D. Fugazza, L.A. Antonelli, 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. Meurs, L. Nicastro,
E. Palazzi, E. Pian, S. Piranomonte, L. Stella, G. Stratta, G.
Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, 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 080319A (GCN 7426, Pagani et al.)
about 40 seconds after the burst.
We do no detect any source at the position of the optical afterglow
identified by Cenko et al. (GCN 7429) and Malesani et al. (GCN 7436)
with a 3sigma upper limit of H~15.0 in the first coadded frame
at about 100sec after the burst.
[GCN OPS NOTE(19mar08): Per author's request, the Cenko reference
was added.]
GCN Circular 7447
Subject
GRB 080319A, Swift-BAT refined analysis
Date
2008-03-19T15:04:20Z (17 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL),
N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
K. McLean (GSFC/UMD), C. Pagani (PSU), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-120 to T+182 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080319A (trigger #306754)
(Pagani, et al., GCN Circ. 7426). The BAT ground-calculated position is
RA, Dec = 206.352, 44.080 deg, which is
RA(J2000) = 13h 45m 24.6s
Dec(J2000) = +44d 04' 47.3"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 7%.
The mask-weighted light curve shows two main over-lapping FRED-like peaks
starting at ~T-5 sec, peaking at T+5 and T+25 sec, and ending at ~T+70 sec.
T90 (15-350 keV) is 64 +- 36 sec (estimated error including systematics).
The time-averaged spectrum from T-7.7 to T+72.3 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.60 +- 0.13. The fluence in the 15-150 keV band is 4.8 +- 0.4 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+31.80 sec in the 15-150 keV band
is 1.2 +- 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/306754/BA/
Due to a large backlog in downlinking the full data on this burst,
we currently do not have the usual data set out to long times yet.
Should the remaining data show that there is ongoing activity
for this burst past the data cutoff at T+182sec, then we will
issue an updated 'refined analysis' circular.
GCN Circular 7448
Subject
GRB 080319A: Enhanced Swift-XRT position
Date
2008-03-19T16:01:24Z (17 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 596 s of overlapping XRT Photon Counting mode and UVOT
data for GRB 080319A, 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 = 206.33318, +44.08038 which is equivalent
to:
RA (J2000): 13h 45m 19.96s
Dec (J2000): +44d 04' 49.4"
with an uncertainty of 1.8 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
http://www.swift.ac.uk/xrt_positions/Goad.pdf).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 7450
Subject
GRB 080319A/B/C: INTEGRAL SPI-ACS light curves available
Date
2008-03-19T16:08:28Z (17 years ago)
From
Volker Beckmann at ISDC <Volker.Beckmann@obs.unige.ch>
V. Beckmann (ISDC), S. Mereghetti (INAF/IASF-Milano), A. von Kienlin
(MPE), M. Beck, V. Savchenko (ISDC), J. Borkowski (CAMK/Torun), D. Gotz
(CEA/Saclay) report on behalf of the INTEGRAL SPI-ACS GRB team:
The three GRB reported on 2008-03-19 by the Swift team (GCN 7426, 7427,
7442) have been independently detected by the SPI Anti-Coincidence
System (ACS) on-board INTEGRAL.
Burst T0 duration max counts in 50 msec
------------------------------------------------------
GRB080319A 05:45:41 10s 370
GRB080319B 06:12:47 57s 5500
GRB080319C 12:25:55 25s 1200
The SPI-ACS light curves are available (both as images and data files)
at http://isdc.unige.ch/Soft/ibas/ibas_acs_web.cgi
The light curves, binned at 50 ms, are derived from 91 independent
detectors with different lower energy thresholds (mainly between 50 keV
and 150 keV) and an upper threshold at about 100 MeV. The ACS response
varies as a function of the GRB incident angle. For these reasons we
caution that the count rates cannot be easily translated into physical
flux units.
GCN Circular 7463
Subject
GRB 080319A: Swift-XRT Team Refined Analysis
Date
2008-03-19T22:07:29Z (17 years ago)
From
Claudio Pagani at PSU/Swift-XRT <pagani@astro.psu.edu>
C. Pagani and J. L. Racusin (PSU) report on behalf of the Swift-XRT team:
The Swift-XRT started observing GRB 080319A (trigger=306754, Pagani et al. GCN
7426) at 05:54:59.4 UT, 557.4s after the trigger. The Swift slew to the burst
was delayed because of an Earth constraint and XRT observations were
interrupted by the Swift trigger on GRB 080319B. The current observations
consist of Photon Counting mode data from T+560s to T+1632s and from T+35ks to
T+37ks.
The best XRT position is the UVOT-enhanced position from Beardmore et al. (GCN
7448), consistent with the optical afterglow position reported by Cenko (GCN
7429).
The 0.3-10 keV X-ray light curve starts at a count rate of ~1 counts/s and shows
a decline with a decay slope of 0.94 +/- 0.05.
The spectrum of the PC data from T+560s to T+1632s can be well fit by an
absorbed powerlaw with photon index 2.1 +/- 0.3 and column density of (1.0 +/-
0.7)e21 cm^-2, in excess of the Galactic column density of 1.45e20 cm^-2 in
this direction. The average observed 0.3-10keV flux is 1.6e-11 erg cm^-2 s^-1,
which corresponds to an unabsorbed flux of 2.1e-11 erg cm^-2 s^-1. The counts
to observed flux conversion factor at the time of this spectrum is 3.7e-11 erg
cm^-2 count^-1.
If the underlying powerlaw decay continues as is, we predict an XRT count rate
of 0.008 counts/s at T+24hr, which corresponds to an observed 0.3-10keV flux of
2.9e-13 erg cm^-2 s^-1.
This circular is an official product of the Swift-XRT team.
GCN Circular 7467
Subject
GRB 080319A SDSS Pre-Burst Observations
Date
2008-03-19T23:12:13Z (17 years ago)
From
Richard J. Cool at U.of AZ/Steward Obs <rcool@as.arizona.edu>
Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona),
David W. Hogg (NYU), Michael R. Blanton (NYU), David J. Schlegel
(LBNL), J. Brinkmann (APO), Donald Q. Lamb (Chicago), Donald
P. Schneider (PSU), and Daniel E. Vanden Berk (PSU) report:
The Sloan Digital Sky Survey (SDSS) imaged the field of burst
GRB080319A prior to the burst. As these data should be useful
as a pre-burst comparison and for calibrating photometry,
we are supplying the images and photometry measurements for
this GRB field to the community.
Data from the SDSS, including 5 FITS images, 3 JPGS, and
3 files of photometry and astrometry, are being placed at
http://mizar.as.arizona.edu/~grb/public/GRB080319A
We supply FITS images in each of the 5 SDSS bands of a 8'x8'
region centered on the GRB position (ra=206.333 (13:45:19.9),
dec=44.0803 (44:04:49.1); GCN 7426), as well as 3 gri
color-composite JPGs (with different stretches). The units
in the FITS images are nanomaggies per pixel. A pixel is
0.396 arcsec on a side. A nanomaggie is a flux-density unit
equal to 10^-9 of a magnitude 0 source or, to the extent that
SDSS is an AB system, 3.631e-6 Jy. The FITS images have WCS
astrometric information.
In the file GRB080319A_sdss.calstar.dat, we report photometry
and astrometry of 227 bright stars (r<20.5) within 15' of the
burst location. The magnitudes presented in this file are asinh
magnitudes as are standard in the SDSS (Lupton 1999, AJ, 118,
1406). Beware that some of these stars are not well-detected
in the u-band; use the errors and object flags to monitor
data quality.
In the files GRB080319A_sdss.objects_flux.dat and
GRB080319A_sdss.objects_magnitudes.dat, we report photometry
of 404 objects detected within 6' of the GRB position.
We have removed saturated objects and objects with model
magnitudes fainter than 23.0 in the r-band. The fluxes listed
in GRB080319A_sdss.objects_flux.dat are in nanomaggies while
the magnitudes listed in GRB080319A_sdss.objects_magnitudes.dat
are asinh magnitudes.
All quantities reported are standard SDSS photometry, meaning
that they are very close to AB zeropoints and magnitudes are
quoted in asinh magnitudes. Photometric zeropoints are known
to about 2% rms. None of the photometry is corrected for
dust extinction. The Schlegel, Finkbeiner, and Davis (1998)
predictions for this region are A_U=0.075 mag, A_g=0.055 mag,
A_r = 0.040 mag, A_i=0.030 mag, and A_z=0.021 mag.
The file GRB080319A_sdss.spectro.dat contains a list of the
6 objects with SDSS spectroscopy within 6 arcminutes of the
GRB position. In addition to the redshift and 1-sigma error
for each object, this file also lists the object spectroscopic
classification.
SDSS astrometry is generally better than 0.1 arcsecond per
coordinate. Users requiring high precision astrometry should
take note that the SDSS astrometric system can differ from
other systems such as those used in other notices; we have
not checked the offsets in this region.
More detailed information pertaining to our SDSS GRB releases
can be found in our initial data release paper (Cool et
al. 2006, PASP 118, 733). See the SDSS DR4 documentation for
more details: http://www.sdss.org/dr5.
These data have been reduced using a slightly different
pipeline than that used for SDSS public data releases.
We cannot guarantee that the values here will exactly match
those in the data release in which these data are included.
In particular, we expect the photometric calibrations to differ
by of order 0.01 mag.
This note may be cited, but please also cite the SDSS data
release paper, Adelman-McCarthy et al. (2007, ApJS, 172, 634),
when using the data or referring to the technical documentation.
GCN Circular 7495
Subject
GRB 080319A: UVOT Observations
Date
2008-03-21T11:33:57Z (17 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <sholland@milkyway.gsfc.nasa.gov>
S. T. Holland (CRESST/GSFC/USRA) and C. Pagani (PSU) report on behalf
of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 080319A starting 542 s
after the BAT trigger (Pagani et al., GCN Circ. 7426). We detect the
optical afterglow in the white filter at the location of the P60
source (Cenko, 2008, GCN Circ. 7429).
Magnitudes and upper limits are reported below.
Filter T_start (s) T_stop Exposure Mag Err Comment
v 669 1544 432 >20.7 3-sigma UL
b 767 1480 29 >19.8 3-sigma UL
u 743 1618 58 >19.9 3-sigma UL
white 562 662 98 21.1 0.3
875 975 98 >21.4 3-sigma UL
The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0 .02 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). No early-time upper
limits are available for the uvw1, uvm2, and uvw2 filters due to the
lack of data resulting from the slew to GRB 080319B, which occurred 25
minutes after GRB 080319A.
GCN Circular 7570
Subject
GRB 080319A: Early RAPTOR optical limits
Date
2008-04-08T20:42:18Z (17 years ago)
From
James Wren at LANL <jwren@nis.lanl.gov>
J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis
of Los Alamos National Laboratory report:
Our RAPTOR telescopes imaged the location of Swift trigger
306754 (Pagani et al., GCN 7426). We do not detect the optical
counterpart initially reported by Cenko et al. (GCN 7429). The
location of the counterpart was within the field of view of our
continuous all-sky monitoring system. We can place 5 sigma
limits at approximately magnitude 9.0 during the time period
within 5 minutes both before and after the trigger. Our
narrow-field instruments began observing the location at
05:46:51.90 UTC, 69.8 s after the Swift trigger, but also did
not detect the counterpart. The limiting magnitudes of our
unfiltered observations when calibrated to the USNO-B1 R-band
are given in the following table.
t-mid(s) exp(s) mag mag-err
--------------------------------------------
-19.18 10.0 9.0 5 sigma limit
14.07 10.0 9.0 5 sigma limit
72.35 5.0 16.9 5 sigma limit
156.60 10.0 17.4 5 sigma limit
423.25 30.0 18.0 5 sigma limit
GCN Circular 7635
Subject
GRB080319A: MAGIC telescope GeV observation
Date
2008-04-20T19:22:07Z (17 years ago)
From
Markus Garczarczyk at MPI/MAGIC <garcz@mppmu.mpg.de>
Garczarczyk M., Gaug M., Antonelli A., Bastieri D., Covino S.,
Galante N., La Barbera A., Longo F. and Scapin V. for the MAGIC
collaboration
The MAGIC Imaging Atmospheric Cherenkov Telescope performed a follow-up
observation of the BAT burst GRB080319A (GCN circular 7426, Pagani et
al.). We received the GCN alert at 05:46:45 UT (T0+63s), data taking with
MAGIC started at 05:50:32 UT (T0+290s). The observation continued for
1736s, starting at the zenith angle of 35 degrees.
No evidence for VHE gamma-ray emission above the analysis threshold of
175 GeV was found. The observation was carried out in (less sensitive)
moon-observation mode.
A preliminary analysis, for the hypothesis of steady emission and
assumption of a differential photon spectral index of -2.5, yields the
following 95% CL differential flux upper limits, including a 30%
systematic uncertainty on the telescope efficiency:
E (125- 175 GeV): 0.57 * 10^-10 erg/cm^2/s
E (175- 300 GeV): 0.11 * 10^-10 erg/cm^2/s
E (300-1000 GeV): 0.06 * 10^-10 erg/cm^2/s
for a time window from 05:50:01 UT to 06:19:01 UT.
For the same time window, we can also exclude emission of a constant flux
in any 100s time bin smaller than:
E (125- 175 GeV): 13.97 * 10^-10 erg/cm^2/s
E (175- 300 GeV): 4.34 * 10^-10 erg/cm^2/s
E (300-1000 GeV): 1.46 * 10^-10 erg/cm^2/s
This message can be cited.
GCN Circular 7636
Subject
GRB 080319A : Liverpool and Faulkes Telescopes Observations
Date
2008-04-21T17:34:09Z (17 years ago)
From
Andrea Melandri at Liverpool John Moores U <axm@astro.livjm.ac.uk>
A. Melandri (Liverpool JMU), A. Gomboc (Ljubljana), C. Guidorzi
(INAF-OAB), R.J. Smith, I.A. Steele, C.G. Mundell, D.F. Bersier,
M.F. Bode, M.J. Burgdorf, S. Kobayashi, C.J. Mottram (Liverpool JMU),
P. O'Brien, N. Bannister, N. Tanvir (U. Leicester) report on behalf of
larger GRB collaboration:
We observed the field of GRB 080319A (trigger = 306754, Pagani et al.
GCN 7426) with the Liverpool Telescope (T_start = 32 min after the burst
event) and the Faulkes Telescope North (T_start = 525 min after the burst
event).
The optical counterpart reported by Cenko et al. (GCN 7429) and Malesani
et al. (GCN 7436), is clearly visible inside the XRT error circle
(Beardmore et al., GCN 7448) in our first images :
Telescope Filter DT_mean(min) Exposure(s) Mag Err
----------------------------------------------------------------------
LT r' 34.2 360 21.45 0.16
LT r' 43.3 600 21.94 0.40
FTN r' 542.3 1000 >20.61
----------------------------------------------------------------------
Magnitudes were calibrated with respect to SDSS calibration's field (Cool
et al. GCN 7467).