GRB 061007
GCN Circular 5787
Subject
GRB 061007: Third Epoch ATCA Radio Observations
Date
2006-11-06T22:40:40Z (19 years ago)
From
Alexander van der Horst at U of Amsterdam <avdhorst@science.uva.nl>
A.J. van der Horst, R.A.M.J. Wijers (University of Amsterdam) and
E. Rol (University of Leicester) report:
"We reobserved the position of the GRB 061007 afterglow at 4.8 and 8.6
GHz with the Australia Telescope Compact Array at November 6 11.50 UT
to 16.41 UT, i.e. 30.06 - 30.26 days after the burst (GCN 5707).
We do not detect a radio source at the position of the optical afterglow
(GCN 5706). The formal flux measurement for a point source at the
location of the optical afterglow is -21 +/- 55 microJy at 4.8 GHz,
and 9 +/- 57 microJy at 8.6 GHz.
We would like to thank the staff of the Australia Telescope National
Facility, in particular Philip Edwards, for obtaining these
Target of Opportunity observations."
GCN Circular 5726
Subject
GRB 061007: Second Epoch ATCA Radio Observations
Date
2006-10-12T22:15:17Z (19 years ago)
From
Alexander van der Horst at U of Amsterdam <avdhorst@science.uva.nl>
A.J. van der Horst (University of Amsterdam) and E. Rol (University of
Leicester) report on behalf of a larger collaboration:
"We reobserved the position of the GRB 061007 afterglow at 4.8, 8.6 and
19 GHz with the Australia Telescope Compact Array at October 12 10.87 UT
to 16.78 UT, i.e. 5.03 - 5.28 days after the burst (GCN 5707).
We do not detect a radio source at the position of the optical afterglow
(GCN 5706). The formal flux measurement for a point source at the
location of the optical afterglow is -1 +/- 43 microJy at 4.8 GHz,
-37 +/- 46 microJy at 8.6 GHz, and -1 +/- 47 microJy at 19 GHz.
We would like to thank the staff of the Australia Telescope National
Facility, in particular Philip Edwards, for obtaining these
Target of Opportunity observations."
GCN Circular 5725
Subject
GRB 061007: RHESSI Spectral Fit
Date
2006-10-09T22:36:02Z (19 years ago)
From
Eric Bellm at UCB/SSL <ebellm@ssl.berkeley.edu>
C. Wigger, E. Bellm, M. Bandstra, S. Boggs, W. Hajdas,
D. M. Smith, and K. Hurley on behalf of the RHESSI team report:
As observed by RHESSI, GRB061007 (Schady et al., GCN 5707; Markwardt et
al., GCN 5713) had a duration of ~73s starting at about T0=10:08:08 UT.
The preliminary fit to the time-integrated RHESSI spectrum of the main
period of emission from (T0+27s) - (T0+64s) between 34 keV and 6 MeV
is a Band function with
alpha = -0.90 +0.27/-0.23
beta = -3.07 +0.40/-1.68
Epeak = 391 +58/-52 keV
(90% confidence levels).
The 20 keV-10 MeV fluence is 1.85 +0.12/-0.10 E-4 erg/cm^2.
GCN Circular 5724
Subject
GRB 061007: Suzaku/WAM observation of the prompt emission
Date
2006-10-09T15:44:20Z (19 years ago)
From
Kazutaka Yamaoka at Aoyama Gakuin U <yamaoka@phys.aoyama.ac.jp>
K. Yamaoka, S. Sugita (Aoyama Gakuin U.), M. Ohno, T. Takahashi,
T. Asano, T. Uehara, Y. Fukazawa (Hiroshima U.), Y. Terada, M. Suzuki,
T. Tamagawa (RIKEN), M. Tashiro, K. Abe, K. Onda, Y. Sato, M. Suzuki,
Y. Urata (Saitama U.), T. Enoto, R. Miyawaki, K. Kokubun, K. Makishima
(Univ. of Tokyo), K. Nakazawa, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.),
on behalf of the Suzaku WAM team report:
The bright, long burst, GRB 061007 (Schady et al., GCN 5707; Markwardt
et al., GCN 5713), triggered the Suzaku Wide-band All-sky Monitor (WAM),
which covers the energy range of 50 keV - 5 MeV, at 10:08:05.627 (UT).
Three large peaks as well as a following smaller peak (GCN 5713) were
clearly seen in the WAM light curve. The T90 duration was about 59 seconds.
The fluence in 100 - 1000 keV was 1.38x10-4 erg/cm2, while the 1-s peak
flux was 14.3 (-1.0,+0.3) photons/cm2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum is
well-described with a GRB Band model as follows.
the low-energy photon index alpha: -0.68 +- 0.11,
the high-energy photon index beta: -2.87 (-0.60, +0.28),
the break energy E0: 425 (-51, +58) keV,
and the peak energy Epeak: 561 (-27, +29) keV.
All the quoted errors are at statistical 90% confidence level,
while systematic errors are not included.
The WAM light curve of this event is available at
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/grb_table.html
GCN Circular 5722
Subject
Konus-Wind observation of GRB 061007
Date
2006-10-09T13:27:23Z (19 years ago)
From
Valentin Pal'shin at Ioffe Inst <val@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and
T. Cline on behalf of the Konus-Wind team report:
The long bright GRB 061007 (Swift-BAT trigger #232683;
Schady et al., GCN 5707; Markwardt et al., GCN 5713)
triggered Konus-Wind at 2006-10-07 T0=36489.344 s UT (10:08:09.344).
As observed by Konus-Wind it had a duration of ~90 s,
fluence 2.49(-0.12, +0.17)x10^-4 erg/cm2,
the 64-ms peak flux measured from T0+39.488
1.95(-0.24, +0.31)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the GRB
(from T0 to T0+87.296 s) is well fitted (in the 20 keV - 10 MeV range)
by GRBM (Band) model for which:
the low-energy photon index is alpha = -0.70 +/- -0.04,
the high energy photon index beta = -2.61 (-0.21, +0.15),
the peak energy Ep = 399 (-18, +19) keV (chi2 = 97/84 dof).
The spectrum of the burst maximum
(accumulated from T0+38.656 s to T0+40.704 s)
is well fitted
(in the 20 keV - 10 MeV range)
by GRBM (Band) model for which:
the low-energy photon index is alpha = -0.53 (-0.08, +0.09),
the high energy photon index beta = -2.61 (-0.49, +0.25),
the peak energy Ep = 498 (-48, +54) keV (chi2 = 51/66 dof).
Assuming z = 1.26 (Osip al., GCN 5715; Jakobsson et al., GCN 5716)
and a standard cosmology
model with H_0 = 70 km/s/Mpc, Omega_M = 0.3, Omega_\Lambda = 0.7,
the isotropic energy release is E_iso ~1.0x10^54 erg, and
the maximum luminosity is (L_iso)_max ~1.8x10^53 erg/s.
All the quoted errors are at the 90% confidence level.
GCN Circular 5720
Subject
GRB 061007: ATCA Radio Observations
Date
2006-10-08T21:38:45Z (19 years ago)
From
Alexander van der Horst at U of Amsterdam <avdhorst@science.uva.nl>
A.J. van der Horst (University of Amsterdam) and E. Rol (University of
Leicester) report on behalf of a larger collaboration:
"We observed the position of the GRB 061007 afterglow at 4.8, 8.6 and
19 GHz with the Australia Telescope Compact Array at October 8 10.25 UT
to 15.84 UT, i.e. 1.00 - 1.24 days after the burst (GCN 5707).
We do not detect a radio source at the position of the optical afterglow
(GCN 5706). The formal flux measurement for a point source at the
location of the optical afterglow is -25 +/- 45 microJy at 4.8 GHz,
-13 +/- 47 microJy at 8.6 GHz, and -1 +/- 37 microJy at 19 GHz.
We would like to thank the staff of the Australia Telescope National
Facility, in particular Baerbel Koribalski, for obtaining these
Target of Opportunity observations."
GCN Circular 5719
Subject
GRB061007: Swift UVOT followup observations
Date
2006-10-08T13:53:47Z (19 years ago)
From
Patricia Schady at MSSL/Swift <ps@mssl.ucl.ac.uk>
P. Schady (MSSL/UCL) and S. Pandey (MSSL/UCL) report on behalf of the
Swift/UVOT team:
The Swift/UVOT began taking data in the field of GRB061007 on 2006-10-07, 80s
after the BAT trigger (Schady et al., GCN 5707), discounting the 10s settling
image. The afterglow reported by Rykoff & Rujopakarn (GCN 5706), is clearly
detected in all six UVOT lenticular filters, and decaying rapidly with a decay
index of ~1.6. The refined position of the afterglow is RA = 03:05:19.6, Dec=
-50:30:02.4 (J2000).
The magnitude of the afterglow in each UVOT filter are given below for the
first exposure taken, and the first long exposure of duration 197s. In the case
of the UVW2 filter, the exposures after 619s after the BAT trigger
had to be coadded to get a detection.
Filter T+(s) Exp(s) Mag
V 395 393 12.84 +/- 0.01
6397 197 17.93 +/- 0.01
B 678 10 14.42 +/- 0.08
5783 197 18.30 +/- 0.08
U 657 19 14.13 +/- 0.05
5578 197 17.77 +/- 0.07
UVW1 635 19 14.89 +/- 0.08
6807 197 19.29 +/- 0.31
UVM2 611 19 16.10 +/- 0.15
6602 197 20.30 +/- 0.69 (1sig)
UVW2 711 19 16.75 +/- 0.17
14813 1279 20.96 +/- 0.36 (1sig)
T+ is the start time of the exposure since the BAT trigger. In the second
reported UVW2 exposure T+ is the midtime of 3 coadded exposures. These
magnitudes are not corrected for the expected extinction of E(B-V)=0.021,
or for coincidince loss.
GCN Circular 5716
Subject
GRB 061007: OA fading and VLT redshift
Date
2006-10-08T09:41:49Z (19 years ago)
From
Pall Jakobsson at U Hertfordshire <palli@star.herts.ac.uk>
Pall Jakobsson (U. Hertfordshire), Johan P. U. Fynbo (DARK, NBI),
Nial Tanvir and Evert Rol (U. Leicester) report on behalf of a
larger collaboration:
Using FORS1 on the Very Large Telescope, we have obtained 3*30 min
spectra (300V grating) of the GRB 061007 field (Schady et al., GCN 5707).
The acquisition image shows that the optical afterglow (Rykoff &
Rujopakarn,
GCN 5706) has R ~ 21.5 on Oct 8.150 (0.727 days post-burst). It is likely
that the host contributes somewhat to the measured flux.
The combined spectrum shows an emission line, presumably corresponding to
[O II] 3727 at z = 1.262. At his redshift we find several other absorption
features, including Mg II and Fe II, consistent with the findings of Osip
et al. (GCN 5715). We also detect the intervening Mg II system at z =1.065.
We thank the Paranal staff for excellent support.
GCN Circular 5715
Subject
GRB 061007: Magellan Spectroscopy
Date
2006-10-08T07:51:33Z (19 years ago)
From
Hsiao-Wen Chen at U Chicago <hchen@oddjob.uchicago.edu>
David Osip (Las Campanas Observatory), H.-W. Chen (U Chicago), and J. X. Prochaska (UCO/Lick Observatory) report on behalf of a larger collaboration:
"We observed the afterglow of GRB061007 reported by Rykoff & Rujopakarn (GCN
5706) and confirmed by Mundel et al. (GCN5708) and Bersier et al., using the
LDSS3 with a 0.75-arcsec slit on the Magellan Clay telescope at the Las
Campanas Observatory. The observations started at 03:54:00 UT on October 8,
2006, ~ 18 hours after the inital Swift/BAT trigger, and were carried out
under a mean seeing condition of 0.75 arcsec in a sequence of five 1200-sec
exposures. The final stacked spectrum covers the spectral range from 3900
Ang to 6500 Ang with a spectral resolution element of 2.4 Ang. In the
spectrum, we identify a strong MgII absorption system, accompanied with
FeII 2344 and 2600 transitions) at z=1.261. We consider this the likely
redshift of GRB061007, given the absence of a strong Lya feature (or any
other strong metal-line transitions) in our spectrum. We also report an
intervening MgII system at z=1.06.
Further analysis is underway.
This message may be cited."
GCN Circular 5714
Subject
GRB 061007: Correction to GCN 5712
Date
2006-10-07T23:37:03Z (19 years ago)
From
Loredana Vetere at PSU <vetere@astro.psu.edu>
L. Vetere, C. Pagani, D. N. Burrows (PSU) and P. Schady (MSSL-UCL) report on
behalf of the Swift XRT team:
The WT spectrum of GRB 061007 given in GCN 5712 has been erroneously computed.
The correct values are given in following paragraphs.
A power-law fit to the WT spectrum gives a photon index of 2.1 +/- 0.2 and a
column density of (1.4 +/- 0.2)e21 cm**-2. We note the galactic hydrogen column
density in the direction of the burst is 2.13e20cm**-2. The 0.2-10.0 keV
observed mean flux during WT observation is 1.5e-09 ergs cm**-2 s**-1, which
corresponds to an unabsorbed flux of 2.2e-09 ergs cm**-2 s**-1.
If the burst continues decaying at the current rate we estimate an XRT
count rate of 0.0069 counts/s at T + 24hr, which corresponds to an
observed 0.2-10.keV flux of 4.2e-13 ergs cm**-2 s**-1.
This circular is an official product of the Swift XRT Team.
GCN Circular 5713
Subject
GRB 061007: Swift-BAT refined analysis
Date
2006-10-07T23:25:05Z (19 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
C. Markwardt (GSFC/UMD), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS),
P. Schady (MSSL-UCL), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
Using the data set from T-58 to T+962 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 061007 (trigger #232683)
(Schady, et al., GCN Circ. 5707). The BAT ground-calculated position is
RA,Dec = 46.299, -50.496 deg {3h 5m 11.8s, -50d 29' 47.4"} (J2000)
+- 0.9 arcmin, (radius, sys+stat, 90% containment). The partial coding
was 19%. Before T-58 sec, the burst location was not in BAT's FOV,
but there is no detection through the side of the instrument of any
significant earlier emission.
The lightcurve shows three large peaks, each with several seconds rise
and fall and a roughly flat top, and each including several sub-peaks.
The first lasts from T-5 to T+15, the second from T+23 to T+40, and the
third from T+40 to T+65 sec. There is a smaller peak starting at T+75,
rising to a flat top from T+78 to T+80 and then declining with a very long
roughly exponential decay. Emission is weakly detectable until around
T+900 sec. T90 (15-350 keV) is 75 +- 5 sec (estimated error including
systematics).
The time-averaged spectrum from T-4.1 to T+231.8 is best fit by a simple
power-law model. The power law index of the time-averaged spectrum
is 1.13 +- 0.03. The fluence in the 15-150 keV band is
4.5 +- 0.1 x 10^-05 erg/cm2. The 1-sec peak photon flux measured from
T+45.14 sec in the 15-150 keV band is 15.3 +- 0.4 ph/cm2/sec. All the
quoted errors are at the 90% confidence level.
GCN Circular 5712
Subject
GRB 061007: Swift XRT refined analysis
Date
2006-10-07T21:21:39Z (19 years ago)
From
Loredana Vetere at PSU <vetere@astro.psu.edu>
L. Vetere, C. Pagani, D. N. Burrows (PSU) and P. Schady (MSSL-UCL) report on
behalf of the Swift XRT team:
We have analysed the first 3 orbits of XRT data from GRB 061007. This is one of
the brightest GRB afterglow ever observed by XRT.
A 5.2ks photon counting mode image provides a refined XRT position:
RA(J2000) = 03 05 19.1
Dec(J2000) = -50 30 01.5
with an uncertainty of 5 arcsec (90% containment). This position is 3.8 arcsec
away from the on-board XRT position and 4 arcsec away from UVOT position
(Schady et al. GCN 5707).
The X-ray light curve shows a rapid decay with a slope of -1.6 +/-0.1. A
power-law fit to the WT spectrum gives a photon index of 2.36 +/- 0.2 and a
column density of (2.2 +/- 0.2)e21 cm**-2. We note the galactic hydrogen column
density in the direction of the burst is 2.13e20cm**-2. The 0.2-10.0 keV
observed mean flux during WT observation is 1.46e-07 ergs cm**-2 s**-1, which
corresponds to an unabsorbed flux of 2.98e-07 ergs cm**-2 s**-1.
If the burst continues decaying at the current rate we estimate an XRT
count rate of 0.0069 counts/s at T + 24hr, which corresponds to an
observed 0.2-10.keV flux of 5.7e-11 ergs cm**-2 s**-1.
This circular is an official product of the Swift XRT Team.
GCN Circular 5709
Subject
GRB 061007 - FTS early brightening and power law decay
Date
2006-10-07T14:45:18Z (19 years ago)
From
David Bersier at Liverpool John Moores U <dfb@astro.livjm.ac.uk>
D. Bersier , C.G. Mundell (Liverpool JMU), C. Guidorzi (Univ Bicocca &
INAF-OAB), A. Gomboc (U. Ljubljana), A. Melandri, C.J. Mottram,
I.A. Steele, R.J. Smith, A. Monfardini, D. Carter, S. Kobayashi,
(Liverpool JMU), E. Rol, P. O'Brien, N. Bannister (Leicester) report:
We observed the optical counterpart of GRB 061007 (GCN 5706, 5707, 5708)
with the 2m Faulkes Telescope South (Siding Spring). At 142 sec after
trigger time, we measure a magnitude of mR=10.15 +/- 0.04 (calibration based
on USNOB1 R2 mag, which may introduce a 0.3 mag systematic uncertainty).
When compared to the magnitude measured by ROTSE (m=13.6, GCN 5706),
this implies a subtantial brightening in the first 2.5 minutes (more
than a factor of 10 between 26 and 142 seconds).
From 142s on, the OT is seen to decay. For the next three hours,
the decay followed a power law with an index of about -1.55 +/- 0.05.
The position of the afterglow is 03:05:19.56, -50:30:2.7 +/- 1.2"
Observations and analysis are continuing.
GCN Circular 5708
Subject
GRB 061007 - Faulkes Telescope South Afterglow Confirmation
Date
2006-10-07T11:11:28Z (19 years ago)
From
Carole Mundell at ARI, JMU,Liverpool <cgm@astro.livjm.ac.uk>
C.G. Mundell (Liverpool JMU), C. Guidorzi (Univ Bicocca & INAF-OAB),
A. Gomboc (University of Ljubljana), C.J. Mottram, A. Melandri,
I.A. Steele, R.J. Smith, A. Monfardini, D. Carter, S. Kobayashi,
D. Bersier, (Liverpool JMU), E. Rol, P. O'Brien, N. Bannister (Leicester)
report:
"The 2-m Faulkes Telescope South (Siding Spring, Australia)
robotically followed up GRB061007 (SWIFT trigger 232683; Schady et
al. GCN #5705) 2.28 min after the GRB trigger time. We find a
fading source at the position reported by Rykoff et al. (GCN #5706)
and Schady et al. (GCN # 5705) and confirm it to be the afterglow of GRB
061007.
Observations and analysis are ongoing."
GCN Circular 5707
Subject
GRB 061007: Swift detection of a burst with an optical counterpart
Date
2006-10-07T10:32:54Z (19 years ago)
From
Patricia Schady at MSSL/Swift <ps@mssl.ucl.ac.uk>
P. Schady (MSSL-UCL), J. R. Cummings (NASA/UMBC),
C. Guidorzi (Univ Bicocca&INAF-OAB), C. Pagani (PSU),
D. M. Palmer (LANL), S. B. Pandey (UCL-MSSL),
P. Romano (Univ. Bicocca & INAF-OAB), G. Sato (GSFC/ISAS),
M. Stamatikos (NASA/ORAU), L. Vetere (PSU) and
H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team:
At 10:08:08 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 061007 (trigger=232683). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA,Dec 46.318, -50.488 {03h 05m 16s, -50d 29' 15"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multi-peaked
structure with a duration of about 100 sec. The peak count rate
was ~25000 counts/sec (15-350 keV), at ~54 sec after the trigger.
The XRT began observing the field at 10:09:29 UT, 80 seconds after the
BAT trigger. XRT found a bright, fading, uncatalogued X-ray source
located at RA(J2000) = 03h 05m 19.5s, Dec(J2000) = -50d 30' 02.1",
with an estimated uncertainty of 7.5 arcseconds (90% confidence
radius). This location is 55 arcseconds from the BAT on-board
position, within the BAT error circle. The initial flux in the 0.1s
image was 3.4e-08 erg/cm2/s (0.2-10 keV).
UVOT took a finding chart exposure of 400 seconds with the V filter
starting 195 seconds after the BAT trigger. There is a very bright
source in the 2.7' x 2.7' sub-image not present in DSS at RA(J2000) =
03:05:19.51 = 46.3313 DEC(J2000) = -50:30:02.5 = -50.5007 with a
1-sigma error radius of about 0.5 arc sec. This position is 0.7 arc
sec. from the center of the XRT error circle. The estimated magnitude
is 12.8 with a 1-sigma error of about 0.5 mag. No correction has been
made for the expected extinction of about 0.1 magnitudes.
GCN Circular 5706
Subject
GRB 061007: ROTSE-III Detection of Optical Counterpart
Date
2006-10-07T10:12:11Z (19 years ago)
From
Eli Rykoff at U of Michigan/ROTSE <erykoff@umich.edu>
E.S. Rykoff (U Mich), W. Rujopakarn (U Mich), report on behalf of the
ROTSE collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded
to GRB 061007 (Swift trigger 232683). The first image was at 10:08:35.2
UT, 26.4 s after the burst (9.2 s after the GCN notice time). The
unfiltered images are calibrated relative to USNO A2.0. We detect a new
object, not visible in the DSS (second epoch), with coordinates:
03:05:19.6 -50:30:02.5 (J2000), with positional
uncertainty of 1" or better
start UT mag mlim(of image)
----------------------------------
10:08:35.2 13.6 14.8
A jpeg image is available at
http://www.rotse.net/images/gsb232683_3a00_img.jpg Note that the object
marked 13 is the candidate in question.
Continuing observations are in progress.