GRB 070201
GCN Circular 6103
Subject
IPN triangulation of GRB070201 (refined error box using MESSENGER data)
Date
2007-02-18T21:40:53Z (20 years ago)
From
Kevin Hurley at UCBerkeley/SSL <khurley@ssl.berkeley.edu>
K. Hurley and J. Goldsten, on behalf of the MESSENGER
GRB team,
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and
T. Cline, on behalf of the Konus-Wind team, and
A. von Kienlin, G. Lichti, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team, report:
The MESSENGER neutron spectrometer, which also serves as a GRB
detector, was turned on recently and has begun to detect bursts.
In particular, it detected GRB070201 (Golenetskii et al., GCN 6088,
6094; Pal'shin et al., GCN 6098). We have now triangulated this
burst to the following error box using MESSENGER, Konus-Wind,
and INTEGRAL SPI-ACS data:
-----------------------------------------------------
RA, deg Dec, deg
-----------------------------------------------------
Center:
11.089 (00h 44m 21s) +42.308 (+42d 18' 27")
Corners:
11.338 (00h 45m 21s) +42.297 (+42d 17' 50")
10.223 (00h 40m 53s) +43.210 (+43d 12' 36")
10.840 (00h 43m 22s) +42.317 (+42d 19' 02")
11.949 (00h 47m 48s) +41.375 (+41d 22' 31")
----------------------------------------------------
As the onboard software is still undergoing verification,
this result should be considered preliminary.
The error box area is 0.325 sq. deg. The center of the box is
1.1 degrees from the center of M31, and includes its spiral
arms. This lends support to the idea that this exceptionally
intense burst may have originated in that galaxy (Perley and
Bloom, GCN 6091).
GCN Circular 6098
Subject
GRB 070201: Correction to GCN 6094
Date
2007-02-12T11:07:25Z (20 years ago)
From
Valentin Pal'shin at Ioffe Inst <val@mail.ioffe.ru>
V. Pal'shin on behalf of the Konus-Wind team report:
The link on the IPN triangulation map was given incorrectly in GCN 6094.
The correct link was given in GCN 6088, that is
http://www.ioffe.rssi.ru/LEA/GRBs/GRB070201_T55390/
We thank David Williams for pointing out the error.
GCN Circular 6094
Subject
GRB 070201: clarification on localization and Konus-Wind spectra
Date
2007-02-10T17:21:40Z (20 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 ecliptic latitudes band of GRB 070201
was given incorrectly in GCN 6088. The correct band is +30 +90 deg.
The coordinates of the portion of the Wind-INTEGRAL annulus
reported in GCN 6088 and the map posted at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB070124_T31311/
are correct
(more accurate coordinates of the intersection the
ecliptic latitude lower limit (+30) with the center of
the annulus are RA, Dec = 13.471, +38.601 deg).
We apologize for the confusion and thank Derek Fox,
Eran Ofek, and Daniel Perley for pointing out the error.
As was noted by Perley and Bloom (GCN 5947)
the burst location area includes the M31 galaxy's outer
spiral arms.
The position of NGC 5985 galaxy suggested by Ofek (GCN 6092)
is definitely out of the burst location area.
The confusion was caused by the error in the reported ecliptic
latitude band.
Preliminary analysis shows that the burst had a
fluence of 1.57(-0.21, +0.06)x10^-5 erg/cm2,
and the 2-ms peak flux measured from T0+0.016 s
9.4(-2.9,+1.7)x10^-4 erg/cm2/s
(both in the 20 keV - 1 MeV energy range).
Assuming this burst originated from a source in M31 (D ~770 kpc),
the isotrpoic energy release would be ~1x10^45 erg,
which is between the energy release in initial pulse
of the 5th March 1979 giant flare from SGR 0526-66 (~2x10^44 erg)
and the 27th December 2004 giant flare from SGR 1806-20 (~2x10^46 erg).
The time-integrated spectrum of the burst
(from T0 to T0+0.256 s) is well fitted (in the 20 keV - 1 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha)*exp(-E*(2-alpha)/Ep)
with alpha = 0.98(-0.11, +0.10)
and Ep = 293 (-31, +38) keV (chi2 = 39/40 dof).
The spectrum of the burst maximum
(from T0 to T0+0.064 s) is well fitted (in the 20 keV - 1 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha)*exp(-E*(2-alpha)/Ep)
with alpha = 0.52(-0.15, +0.14)
and Ep = 357 (-38, +44) keV (chi2 = 39/40 dof).
All the quoted errors are at the 90% confidence level.
Due to large uncertainties in the burst position
and large dead times caused by very high count rates
these values should be considered only as preliminary.
GCN Circular 6092
Subject
GRB 070201: IPN constraints and nearby galaxies
Date
2007-02-10T00:43:43Z (20 years ago)
From
Eran Ofek at Tel Aviv U. <eran@wise1.tau.ac.il>
E. O. Ofek (Caltech) report:
I note that the IPN coordinate constraints of GRB 070201 (Golenetskii et al.; GCN 6088)
do not contain the position of the galaxy M31 (cf. Perley & Bloom; GCN 6091).
The ecliptic latitude of M31 is 33.3 deg, while the Konus/Wind satellite
constrained the ecliptic latitude of this burst to lay between +60 and +90 deg.
However, the relatively massive/nearby spiral galaxy NGC 5985 (distance of ~40
Mpc) satisfies the IPN constrains.
A plot of the galaxy position and IPN annulus is in:
http://www.astro.caltech.edu/~eran/GRB/070201/NGC5985.jpg
I further note that the total area within the IPN constraint is about 8 sq deg.
GCN Circular 6091
Subject
GRB 070201: Proximity of IPN annulus to M31
Date
2007-02-09T23:40:23Z (20 years ago)
From
Daniel Perley at U.C. Berkeley <dperley@astro.berkeley.edu>
D. A. Perley and J. S. Bloom (UC Berkeley) report:
The IPN annulus quoted in GCN 6088 passes within a minimum distance of
45 arcminutes from the center of M31, and through the galaxy's outer
spiral arms. Given the close proximity of a previous extremely bright
IPN short burst (GCN 4197) with the nearby spiral galaxy M81 and the
possibility of a physical association of that event with that galaxy
(Ofek et al. 2006, Ap.J. v.652 p.507; Frederiks et al. 2007, Ast.L. v.33
p.19), further investigations are strongly encouraged despite the large
time delay between the burst and the distribution of the coordinates.
GCN Circular 6088
Subject
IPN localization of very intense short GRB 070201
Date
2007-02-09T19:53:47Z (20 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,
A. von Kienlin, G. Lichti, A. Rau, D. Gotz, and S. Mereghetti,
on behalf of the INTEGRAL GRB team,
J. Cummings, S. Barthelmy, N. Gehrels, and H. Krimm, on behalf of
the Swift-BAT team,
K. Hurley, D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger,
W. Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team,
and
K.Yamaoka, M.Ohno, Y.Fukazawa, T.Takahashi, M.Tashiro, Y. Terada,
T.Murakami, and K.Makishima on behalf of the Suzaku WAM team
report:
An extremely intense short, hard GRB triggered Konus-Wind
at 2007-02-01 T0=55390.780 s UT (15:23:10.780).
It also triggered INTEGRAL-SPI-ACS. Swift-BAT observed it at a very high
background level while entering the SAA.
The burst was Earth-occulted to Suzaku and RHESSI,
and Mars-occulted to Odyssey. Ulysses was off.
This burst had the highest peak count rate of any cosmic
GRB observed by Konus-Wind in 12 years of operation (SGR
bursts excluded).
The burst light curve shows a main multipeaked pulse
with a duration of ~0.15 s, which was followed by a much weaker softer
pulse with a duration of ~0.08 s.
The burst demonstrates strong spectral evolution.
It was triangulated to the Wind-INTEGRAL annulus
centered at RA=114.847 (07h 39m 23s) Dec=+23.826 (+23d 49' 33"),
whose radius is 83.626 +/- 0.160 deg (3 sigma).
The Konus ecliptic latitude response constrains the arrival direction
to a band between ecliptic latitudes +60 and +90 degrees.
Combined with the occultation data, this
constrains the arrival direction to that portion of the
annulus between RA, Dec = 13, +37 and 350, +62 degrees.
As observed by Konus-Wind the burst had a fluence of ~2x10^-5 erg/cm2
and a peak flux of ~1x10^-3 erg/cm2/s (both in the 20-2000 keV range).
Epeak of the time-integrated spectrum is ~300 keV.
The K-W light curve of this GRB and IPN triangulation map can be seen
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB070201_T55390/
Detailed spectral parameters will be reported later.