- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Sat 10 Oct 09 02:43:13 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 46
TRIGGER_NUM: 276835391
GRB_RA: 299.900d {+19h 59m 36s} (J2000),
300.044d {+20h 00m 10s} (current),
299.165d {+19h 56m 40s} (1950)
GRB_DEC: -21.233d {-21d 13' 59"} (J2000),
-21.206d {-21d 12' 21"} (current),
-21.371d {-21d 22' 13"} (1950)
GRB_ERROR: 3.62 [deg radius, statistical plus systematic]
GRB_INTEN: 2774 [cnts/sec]
DATA_SIGNIF: 64.60 [sigma]
INTEG_TIME: 0.256 [sec]
GRB_DATE: 15114 TJD; 283 DOY; 09/10/10
GRB_TIME: 9789.32 SOD {02:43:09.32} UT
GRB_PHI: 304.00 [deg]
GRB_THETA: 55.00 [deg]
DATA_TIME_SCALE: 0.2560 [sec]
HARD_RATIO: 0.73
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 96% GRB
2nd_MOST_LIKELY: 2% Generic Transient
DETECTORS: 0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN: 195.61d {+13h 02m 25s} -6.65d {-06d 39' 05"}
SUN_DIST: 100.89 [deg] Sun_angle= -7.0 [hr] (East of Sun)
MOON_POSTN: 90.57d {+06h 02m 18s} +25.66d {+25d 39' 49"}
MOON_DIST: 152.65 [deg]
MOON_ILLUM: 64 [%]
GAL_COORDS: 20.42,-24.09 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 297.69, -0.62 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 288.97,21.77 [deg].
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Sat 10 Oct 09 02:43:35 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 59
TRIGGER_NUM: 276835391
GRB_RA: 299.967d {+19h 59m 52s} (J2000),
300.110d {+20h 00m 26s} (current),
299.231d {+19h 56m 55s} (1950)
GRB_DEC: -21.333d {-21d 19' 59"} (J2000),
-21.306d {-21d 18' 21"} (current),
-21.471d {-21d 28' 14"} (1950)
GRB_ERROR: 3.52 [deg radius, statistical plus systematic]
GRB_INTEN: 3792 [cnts/sec]
DATA_SIGNIF: 119.50 [sigma]
INTEG_TIME: 0.512 [sec]
GRB_DATE: 15114 TJD; 283 DOY; 09/10/10
GRB_TIME: 9789.32 SOD {02:43:09.32} UT
GRB_PHI: 304.00 [deg]
GRB_THETA: 55.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO: 0.80
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 96% GRB
2nd_MOST_LIKELY: 1% Generic Transient
DETECTORS: 0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN: 195.61d {+13h 02m 26s} -6.65d {-06d 39' 05"}
SUN_DIST: 100.93 [deg] Sun_angle= -7.0 [hr] (East of Sun)
MOON_POSTN: 90.58d {+06h 02m 19s} +25.66d {+25d 39' 48"}
MOON_DIST: 152.62 [deg]
MOON_ILLUM: 64 [%]
GAL_COORDS: 20.34,-24.19 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 297.73, -0.73 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 288.97,21.77 [deg].
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Sat 10 Oct 09 02:43:42 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 58
TRIGGER_NUM: 276835391
GRB_RA: 289.980d {+19h 19m 55s} (J2000),
290.128d {+19h 20m 31s} (current),
289.225d {+19h 16m 54s} (1950)
GRB_DEC: -23.620d {-23d 37' 11"} (J2000),
-23.601d {-23d 36' 04"} (current),
-23.713d {-23d 42' 47"} (1950)
GRB_ERROR: 1.59 [deg radius, statistical only]
DATA_SIGNIF: 128.60 [sigma]
DATA_INTERVAL: 0.512 [sec]
GRB_DATE: 15114 TJD; 283 DOY; 09/10/10
GRB_TIME: 9789.32 SOD {02:43:09.32} UT
GRB_PHI: 310.00 [deg]
GRB_THETA: 63.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 413 (Gnd S/W Version number)
SUN_POSTN: 195.61d {+13h 02m 26s} -6.65d {-06d 39' 05"}
SUN_DIST: 91.45 [deg] Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN: 90.58d {+06h 02m 19s} +25.66d {+25d 39' 48"}
MOON_DIST: 162.13 [deg]
MOON_ILLUM: 64 [%]
GAL_COORDS: 14.40,-16.49 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 288.25, -1.44 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS: Fermi-GBM Ground-calculated Coordinates.
COMMENTS: This Notice was ground-generated -- not flight-generated.
- GCN circular #10004
I. Donnarumma, Y. Evangelista, E. Del Monte, M. Feroci, F. Lazzarotto,
L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda
(INAF/IASF Rome), A. Giuliani, A. Chen, S. Mereghetti, F. Perotti,
P. Caraveo (INAF/IASF Milan), A. Pellizzoni, M. Pilia (INAF/OA Cagliari),
S. Vercellone (INAF/IASF Palermo), A. Bulgarelli, F. Gianotti,
M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi,
M. Galli, (INAF/IASF Bologna), M. Tavani, G. Pucella, F. D'Ammando,
E. Striani, V. Vittorini, A. Argan, A. Trois, G. Piano, S. Sabatini
(INAF/IASF Rome), G. Barbiellini, F. Longo, E. Moretti (INFN Trieste),
P. Picozza, A. Morselli (INFN Roma-2), M. Prest, E. Vallazza (Universita`
dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1), and P. Giommi,
C. Pittori, P. Santolamazza, F. Verrecchia (ASDC) and L. Salotti (ASI),
on behalf of the AGILE Team, report:
"SuperAGILE detected a long gamma ray burst on 10 October 2009,
at 02:43:09 UT. The event had a duration of about 10 s in the 17-60 keV
energy range, with a highly structured shape. Assuming a Crab-like energy
spectrum, the peak flux on 1-s timescale was about 6.2E-07 erg/cm2/s.
The burst position was reconstructed as (RA, Dec)
(298.669, -22.538) deg, which is:
RA(J2000) = 19h 54m 40.51s
Dec(J2000) = -22d 32' 17.36"
with an uncertainty of 3' radius. The given uncertainty accounts
for both the statistical and systematic errors.
An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress."
- GCN circular #10005
Marco Feroci (INAF/IASF Rome) reports:
I made a mistake in the name of the GRB, that is GRB 091010
instead of GRB 090910, as cited in the previous circular.
The burst trigger time indicated in GCN #10004 was correct.
I apologize for the confusion.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/SuperAGILE NOTICE
NOTICE_DATE: Sat 10 Oct 09 07:15:20 UT
NOTICE_TYPE: SuperAGILE GRB Ground Position
TRIGGER_NUM: 1162
GRB_RA: 298.669d {+19h 54m 41s} (J2000),
298.814d {+19h 55m 15s} (current),
297.926d {+19h 51m 42s} (1950)
GRB_DEC: -22.538d {-22d 32' 16"} (J2000),
-22.512d {-22d 30' 42"} (current),
-22.670d {-22d 40' 11"} (1950)
GRB_ERROR: 3.00 [arcmin radius, statistical plus systematic]
GRB_INTEN: 735.935 706.263 [X & Y cnts]
GRB_SIGNIF: 17.01 15.71 [sigma]
GRB_DATE: 15114 TJD; 283 DOY; 09/10/10
GRB_TIME: 9789.00 SOD {02:43:09.00} UT
SUN_POSTN: 195.78d {+13h 03m 07s} -6.72d {-06d 43' 22"}
SUN_DIST: 99.33 [deg] Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN: 93.50d {+06h 13m 59s} +25.41d {+25d 24' 32"}
MOON_DIST: 156.72 [deg]
MOON_ILLUM: 62 [%]
GAL_COORDS: 18.64,-23.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 296.31, -1.68 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS: SuperAGILE GRB Coordinates.
COMMENTS: This is a GRB.
COMMENTS: SuperAGILE ground GRB coordinates
- GCN Circular #10006
R. Margutti (INAF-OAB) & C. Guidorzi (U. Ferrara) report on behalf
of the Swift XRT team:
We have analyzed the first orbit data (1.8 ks exposure) of the
Swift ToO observation of the SuperAGILE detected (Donnarumma et al.,
GCN Circ. 10004; Feroci, GCN Circ 10005) burst GRB 091010.
The Swift observation started on 2009 Oct 10 at 14:48:26 UT, about
43 ks after the SuperAGILE trigger.
We detected a single, uncatalogued X-ray source within the SuperAGILE
error box at RA, Dec =298.6661, -22.5181 which is equivalent to:
RA (J2000): 19h54m39.86s
Dec (J2000): -22:31:05.2
with an uncertainty of 4.3 arcsec (radius, 90% confidence).
The source lies 72 arcsec from the SuperAGILE position.
The source has a count rate of about 5.7E-02 count s^-1.
At the moment it is not possible to determine whether the source is
fading given the current statistics.
Burst Advocate for this burst is R. Margutti
(raffaella.margutti AT brera.inaf.it).
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.)
This is an official product of the Swift-XRT team.
- GCN Circular #10007
P.A. Curran (MSSL-UCL) and R. Margutti (INAF-OAB) report on behalf of the
Swift/UVOT team:
The Swift/UVOT began ToO observations of the field of the SuperAGILE
detected GRB 091010 (Donnarumma et al., GCN 10004) on 2009 Oct 10 at
14:48:26 UT.
No optical afterglow consistent with the Swift XRT position (Margutti et
al., GCN 10006) is detected in the UVOT exposures. Preliminary 3-sigma
upper limits, using the UVOT photometric system (Poole et al. 2008, MNRAS,
383, 627), for the exposures are:
Filter Time(s) Exp(s) Mag
--------------------------------------
wh 4.41e4 498 >21.36
v 4.47e4 609 >19.86
u 4.35e4 567 >20.48
The values quoted above are not corrected for the Galactic extinction due
to the reddening of E(B-V) = 0.10 in the direction of the burst (Schlegel
et al. 1998).
- GCN Circular #10008
A. Rossi (Tautenburg), A. Rau, P. Afonso and J. Greiner (all MPE),
report on behalf of the GROND team:
Starting October 10 at 23h45 UT (21.03hrs post-burst) GROND (Greiner et
al. 2008, PASP 120, 405) mounted at the 2.2m ESO/MPI telescope
at La Silla Observatory (Chile) imaged the field of GRB 091010
(Donnarumma et al., GCN #10004) simultaneously in the g'r'i'z'JHK bands.
Within the Swift-XRT circle (Margutti et al., GCN #10006) we find a
single source at:
RA(J2000): 19:54:39.80
DEC(J2000): -22:31:03.9
with uncertainties of 0.5" in each coordinate.
The object is detected in the r' band with a preliminary AB magnitude of
~22.2 calibrated against the GROND photometric zero point. No correction
for Galactic foreground extinction of E(B-V)=0.14mag (Schlegel et al.
1998, Apj, 500, 525) was applied. Strongly variable sky conditions and
high seeing >2.5 arcsec) prevent reliable detections in others bands.
- GCN Circular #10011
Arto Oksanen and Eric Southgate (The Hermitage Observatory, Sunshine
Coast, QLD, Australia) report to the AAVSO International High Energy
Network the following optical observations of the field of GRB 091010 (GCN
Circ. #10004, Donnarumma et al.):
A. Oksanen and E. Southgate report an upper limit of approximately CR=17.5
on the optical afterglow of GRB 091010 (GCN Circ. #10004, Donnarumma et
al.). The afterglow upper limit was measured relative to the star
USNO-B1.0 0674-0991959. A single, 120-second observation was made using
an A&M 130-mm TMB APO with an SBIG ST2000 CCD camera and no filter. The
mid-point of the exposure was 2009 October 10, 11:19:17 UT, approximately
8.6 hours after the SuperAGILE trigger. The entire error box of the burst
centered on RA 19h 54m 40.51s , Dec -22d 32m 17.36s was imaged; no new
sources were detected using visual comparison of the CCD image with the
DSS2 R-band plate of the area.
A stacked, 10 x 120-second image was also created from subsequent images
of the field using the same camera. The midpoint of this image was 2009
October 10 11:47 UT, approximately 9.0 hours after the burst. This image
was visually examined, and no candidate objects were found; the image
extends to approximately the same depth as the DSS2 red plate.
A FITS image of the initial observation is available at the following URL:
ftp://ftp.aavso.org/grb/ArtoOksanen_GRB091010_2455115.12128_.fits
The AAVSO thanks the Curry Foundation for its support of the AAVSO
International High Energy Network.
- GCN Circular #10012
P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team:
Using 3934 s of XRT Photon Counting mode data and 4 UVOT images, 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 = 298.66550,
-22.51820 which is equivalent to:
RA (J2000): 19 54 39.72
Dec (J2000): -22 31 05.7
with an uncertainty of 1.9 arcsec (radius, 90% confidence). This is consistent
with the position of the candidate optical afterglow seen by GROND (Rossi et al.
GCN Circ. 10008).
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 is an official product of the Swift-XRT team.
- GCN Circular #10013
S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline
on behalf of the Konus-Wind team, report:
The long GRB 091010 (Donnarumma et al., GCN Circ. 10004; Feroci, GCN Circ=
10005)
triggered Konus-Wind at T0=3D09788.232 s UT (02:43:08.232).
The burst light curve shows a multipeaked structure with a total
duration of ~8 s. The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB091010_T09788/
As observed by Konus-Wind the burst
had a fluence of (9.4 =B1 1.1)x10-6 erg/cm2,
and a 64-ms peak flux measured from T0 + 2.240s
of (8.3 =B1 1.0)x10-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).
The time-integrated spectrum of the burst (from T0 to T0+8.448 s)
is well fitted in the 20 keV - 2 MeV range by GRB (Band) model for which:
the low-energy photon index alpha =3D -1.20 (-0.28, +0.35),
the high energy photon index beta =3D -2.9(< -2.4),
the peak energy Ep =3D 119(-17, +19) keV (chi2 =3D 55/59 dof).
All the quoted errors are at the 90% confidence level.
- GCN Circular #10014
A.L. Watts, A. Patruno, M. van der Klis (U.v. Amsterdam),
P. Casella (Southampton),
P.A. Curran (MSSL-UCL),
D. Altamirano, Y. Cavecchi, N. Degenaar, R. Kaur, M. Linares, P. Soleri,
R. Wijnands, A. Kamble (U.v. Amsterdam)
and N. Rea (ICE-CSIC/IEEC) report:
RXTE observations taken at the time of the SuperAGILE detected burst GRB=20
091010 (Donnarumma et al., GCN Circ. 10004; Feroci, GCN Circ 10005) also=20
recorded the event.=C2=A0
The RXTE PCA detected two strong flares in emission, the first coinciding=
=20
with the SuperAGILE trigger time (02:43:09 UT) and the other 2s later.=C2=
=A0=20
Each flare lasted ~1s. There is also evidence for a third weaker flare 5s=
=20
after the trigger. Peak count-rate (2-60 keV, 0.1s binning) for the first=
=20
flare is 250 counts/s, and for the second flare is 500 counts/s.=C2=A0The=
RXTE=20
lightcurve can be found at
http://staff.science.uva.nl/~pgcasell/GRB091010
At the time RXTE was observing XTE J1751-305, with nominal pointing
direction
RA(J2000)= 17h 51m 13.49s
Dec(J2000) = -30d 39' 23.4"
so was approximately 28 degrees off-axis from GRB 091010.=C2=A0 For this
reason
spectral and timing information will be degraded.=C2=A0Preliminary timing
analysis reveals no significant periodic variability.=C2=A0The flares are
not
detected strongly below 30 keV.
Although bright, this GRB did not have an exceptionally high peak flux.=C2=
=A0=20
It is therefore perhaps a little surprising that RXTE was able to record=20
this event so strongly given the offset angle.=C2=A0Reflections in the=20
collimator may be responsible (see Laros et al. 1985).
We would like to thank the SuperAGILE team for providing us with their=20
lightcurve for GRB 091010, which enabled us to confirm the RXTE=20
identification.
- GCN Circular #10017
C. Guidorzi (U. Ferrara), A. Gomboc (U. Ljubljana), D. Bersier,
Z. Cano, S. Kobayashi, A. Melandri, C.J. Mottram, C.G. Mundell,
R.J. Smith, I.A. Steele (Liverpool JMU), N.R. Tanvir
(U. Leicester) on behalf of a large collaboration report:
We began observing the SuperAGILE GRB 091010 (Donnarumma
et al. GCN Circ. 10004) with the 2-m Faulkes Telescope North
(FTN) on October 11, 04:54:49 UT (26.2 hours post burst)
with the BVRi' filters.
We clearly detect the GROND afterglow candidate (Rossi
et al. GCN Circ. 10008) with the Ri' filters with the
following magnitudes:
Telescope Mid Time Exposure Filter Mag
(hours) (s)
-------------------------------------------------------
FTN 27.5 7x300 i' 22.11 +- 0.15
FTN 27.6 6x300 R 22.2 +- 0.2
-------------------------------------------------------
Calibration was performed against a nearby USNOB-1 star:
RA(J2000), Dec(J2000)= 19:54:38.242, -22:31:27.11 assuming
R2=14.89 and i'=15.02.
Compared with GROND measurements, we cannot confirm any
fading of the source due to the closeness in time between
our observations.
- GCN Circular #10018
A. von Kienlin, E. Bissaldi and D. Gruber (all MPE)
report on behalf of the Fermi GBM Team:
"At 02:43:09.32 UT on 10 October 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 091010 (trigger 276835391 / 091010113),
which was also detected by SuperAGILE (Donnarumma et al., GCN 10004).
The GBM on-ground location is consistent with the Swift-XRT position
(Margutti et al. 2009, GCN 10006 and Evans et al. 2009, GCN 10012).
The angle from the Fermi LAT boresight is 55.7 degrees.
Moreover, this burst was bright enough to result in
a Fermi spacecraft repointing maneuver.
This burst was also independently detected by INTEGRAL SPI-ACS.
The GBM light curve consists of multiple peaks
with a duration (T90) of about 8.1 +/- 0.5 s (8-1000 keV).
The time-averaged spectrum from T0-0.128 s to T0+8.064 s is
best fit by a power law function with an exponential
high energy cutoff. The power law index is -1.11 +/- 0.03 and
the cutoff energy, parameterized as Epeak, is 150 (+6/-5) keV
(C-stat 446 for 359 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(1.09 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.9 s in the 8-1000 keV band
is 40.9 +/- 0.5 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
- GCN Circular #10022
M. Marisaldi, F. Fuschino (INAF/IASF Bologna), F. Longo, E. Moretti
(INFN Trieste), A. Bulgarelli, F. Gianotti, M. Trifoglio, M. Galli, C.
Labanti, G. Di Cocco (INAF/IASF Bologna), E. Del Monte, I. Donnarumma,
Y. Evangelista, M. Feroci, F. Lazzarotto, L. Pacciani, P. Soffitta, E.
Costa, I. Lapshov, M. Rapisarda, A. Argan, F. D'Ammando, G. Piano, G.
Pucella, S. Sabatini, E. Striani, M. Tavani, A. Trois, V. Vittorini
(INAF/IASF Roma), A. Chen, A. Giuliani, S. Mereghetti, P. Caraveo, F.
Perotti (INAF/IASF Milano), A. Pellizzoni, M. Pilia (INAF/OA Cagliari),
S. Vercellone (INAF/IASF Palermo), G. Barbiellini, E. Vallazza (INFN
Trieste), A. Morselli, P. Picozza (INFN Roma-2), M. Prest (Universita`
dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1), P.W. Cattaneo, A.
Rappoldi (INFN Pavia), S. Cutini, P. Giommi, C. Pittori, P.
Santolamazza, F. Verrecchia (ASDC), L. Salotti (ASI)
"The long GRB 091010 localized by SuperAGILE (Donnarumma et al., GCN
10004) triggered also the MCAL instrument onboard AGILE, sensitive in
the energy range 330 keV - 100 MeV, at 02:43:10 UT (T0).
As seen by MCAL the burst has a double-peaked light curve, with a
duration of 3.5 s.
The time integrated spectrum in the time interval [T0-1.5 s, T0+2.0 s]
can be fit in the energy range 400 keV - 2 MeV with a single powerlaw
with photon index -3.0 (-0.6, +0.8) (reduced chi2 = 1.09 with 9 d.o.f.).
The estimated fluence is (1.40 +/- 0.3)x10-6 erg/cm2 in the same energy
range.
All reported errors are at the 90% confidence level.
No significant emission is detected above 2 MeV.
The photon index and fluence are consistent with those reported by
Konus-Wind (Golenetskii et al., GCN 10013), when the different energy
range is accounted for.
No significant emission is detected by AGILE GRID.
A 3-sigma Upper Limit for emission in the GRID energy range (E>30 MeV)
in the same 3.5 seconds time interval used for MCAL analysis can be
placed at 0.043 ph/cm2.
Using a 60-seconds time interval starting from T0 the 3-sigma Upper
Limit is 0.1 ph/cm2."
- GCN Circular #10023
N. Vasquez (Tokyo Tech.), M. Ohno, M. Suzuki,M. Kokubun,
T. Takahashi (ISAS/JAXA), K. Yamaoka (Aoyama Gakuin U.),
N. Ohmori, E. Sonoda, K. Kono, H. Hayashi, A. Daikyuji,
Y. Nishioka, K. Noda, M. Yamauchi (Univ. of Miyazaki),
Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.),
W. Iwakiri, M. Tashiro, Y. Terada, A. Endo, K. Onda, T. Sugasahara
(Saitama U.),
Y. Urata (NCU), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo),
Y. E. Nakagawa, T. Tamagawa (RIKEN), S. Hong (Nihon U.),
S. Sugita (Nagoya U.)on behalf of the Suzaku WAM team, report:
The long GRB 091010 (Fermi trigger #276835391/091010113,
von Kienlin et al., GCN10018, SuperAGILE Donnarumma et al., GCN 10004)
triggered the Suzaku Wide-band All-sky Monitor (WAM) in a energy
range from
50 keV to 5 MeV at 02:43:09.50 UT (=T0).
The observed light curve shows a multi-peaked structure, starting at
T0 s and ending at T0+7s, with a total duration (T90) of 6.5 s.
The fluence in 100 - 1000 keV was 6.22(+0.48,-0.42) x 10-6 erg/cm^2.
The 1-s peak flux measured from T0+1 s was 9.91(+0.89,-1.03) photons/s/
cm^2
in the same energy range.
Preliminary result shows that the time-averaged spectrum from
T0-1s to T0+7s is well fitted by a single power-law with
a photon index of 2.50 (+0.24,-0.22) (chi^2/d.o.f = 11.7/8).
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.
The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html
- GCN Circular #10024
R. Margutti (INAF-OAB) reports on behalf of the Swift-XRT team:
The Swift ToO observations of the SuperAGILE GRB 091010
(Donnarumma et al., GCN Circ. 10004; Feroci, GCN Circ. 10005) started
on 2009 Oct 10th at 14:48:26 UT. The XRT data set consists of 9 ks
exposure in PC mode. The UVOT-enhanced XRT position was given by
Evans et al. in GCN Circ. 10012.
The X-ray source reported by Margutti & Guidorzi, GCN Circ. 10006
has faded to a level of (2.4 +/- 1.0)e-3 count/sec, with a best fit
power-law decay index of alpha=-1.4 +/- 0.6 .
This source is thus confirmed as the afterglow of GRB 091010.
The spectrum extracted in the time interval 43-50 ks contains about
170 photons and can be fitted using an absorbed power law model.
Spectral channels have been grouped so as to have 5 counts per bin
and then weighted using the Churazov method (Churazov et al. 1996).
The best fit photon index is found to be 2.3 +/- 0.4. The spectrum
shows evidence of absorption at the level of (1.9 +/- 0.1)e21 cm-2,
in excess of the Galactic value in the direction of the burst which
is 8.1e20 cm-2, Kalberla et al. 2005.
The observed (unabsorbed) flux over this time interval is 1.5e-12
(2.8e-12) erg cm^-2 s^-1. The counts to observed (unabsorbed) 0.3-10 keV
flux conversion factor deduced from this spectrum is 3.6 x 10^-11
(6.6 x 10^-11) erg cm^-2 count^-1.
All quoted errors are at 90% confidence level.
The results of the xrt automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020116.
This is an official product of the Swift-XRT team.
- GCN Circular #10027
C. Guidorzi (U. Ferrara), A. Melandri, C.G. Mundell, D. Bersier,
Z. Cano, N.R. Clay, S. Kobayashi, C.J. Mottram, R.J. Smith,
I.A. Steele (Liverpool JMU), A. Gomboc (U. Ljubljana),
N.R. Tanvir (U. Leicester) on behalf of a large collaboration
report:
We re-observed the optical afterglow candidate (Rossi et al.
GCN Circ. 10008) of the SuperAGILE GRB 091010 (Donnarumma
et al. GCN Circ. 10004) with the 2-m Faulkes Telescope South
(FTS) on October 16, 09:27:33 UT (6.3 days post burst)
with the Ri' filters.
The source is still clearly detected in both filters.
Comparison with our previous values obtained at 1 day
post burst (Guidorzi et al. GCN Circ. 10017) shows that
the source did not fade appreciably.
We derived an upper limit to the possible power-law
decay index of alpha<0.5 (90% confidence) from 1 to
6 days post burst, flux~t^(-alpha).
Given that a comparably shallow and long-lasting decay
has never been observed, we can confidently rule out
this source as the optical afterglow of GRB 091010.
Telescope Mid Time Exposure Filter Mag
(days) (s)
-----------------------------------------------------
FTS 6.29 6x300 i' 22.2 +- 0.3
FTS 6.31 6x300 R 22.3 +- 0.3
-----------------------------------------------------
Calibration was the same as that used in our previous
report (GCN Circ. 10017).
- GCN Circular #10030
V. Rumyantsev (CrAO), E. Klunko (ISTP) and A. Pozanenko (IKI) report on
behalf of larger GRB follow-up collaboration:
We observed the field of SuperAGILE GRB 091010 (Donnarumma et al. GCN 10004)
with Shajn telescope of CrAO on Oct. 12 between (UT) 16:55:18 -
18:09:40. In the XRT error circle (Margutti et al. GCN 10006) we detect a
single object at coordinates (J2000) RA: 19 54 39.80 Dec: -22 31 04.71. The
coordinates of the object coincide with OT candidate reported by Rossi et
al. (GCN 1008).
The photometry against nearby USNO-B1.0 stars (0674-0991940 RA:19 54 39.26
Dec: -22 31 29.7 R=18.18, 0674-0991922 RA:19 54 38.07 Dec: -22 31 12.4
R=17.27) is following:
T0+ Filter, Exposure, mag., err.
(d) (s)
2.62 R 71x60 22.40 +/- 0.17
Our photometry confirm the absence of variability of the OT candidate (Rossi
et al.GCN 1008, Guidorzi et al.GCN 10027). However the object looks like
extended in E-W direction, and can be a candidate in a host galaxy of GRB
091010.
The combined image can be found in
http://grb.rssi.ru/GRB091010/GRB091010_091012_R_ZTSh.gif
- GCN Circular #10128
Daniel Kocevski (SLAC), Aurelien Bouvier (SLAC), Julie McEnery
(NASA/GSFC), Jim Chiang (SLAC), Elena Moretti (INFN Trieste), Vlasios
Vasileiou (NASA/GSFC & UMBC) and Frederic Piron (LPTA) report on
behalf of the Fermi LAT team:
We present the flux and fluence upper limits based on the
non-detection of GRB 091010 (trigger 276835391 / 091010113) (GCN
10004, GCN 10018) by the Fermi Large Area Telescope (Fermi LAT) in the
0.1-300 GeV band. As reported by Kienlin et al. 2009, GCN 10018, GRB
091010 was well detected by the Fermi Gamma-ray Burst Monitor with a
1-sec peak photon flux in the 8-1000 keV band of 40.9 +/- 0.5
ph/s/cm^2 and was sufficiently bright to trigger a spacecraft
repointing maneuver. The burst occurred 55.7 degrees off axis with
respect to the LAT boresight. The subsequent repoint maneuver resulted
in pointed observations starting 200 seconds post trigger and lasting
for approximately 5 hours.
No significant emission was detected in the LAT band during any of the
time intervals in which the burst was in the LAT field of view. We use
a Bayesian method (as described in Abdo et al. 2009: arXiv:0910.4192)
to determine the 95% CL upper limits on the LAT energy flux and
fluence for several time intervals with respect to the GRB trigger
time (02:43:09.32 UT, October 10th 2009):
Prompt Emission (T0 to T0+8.1s):
95% Energy Flux Upper Limit = 1.94e-7 erg/s/cm^2
95% Energy Fluence Upper Limit = 1.57e-06 erg/cm^2
Extended Emission Interval 1 (T0-200s to T0+200s):
95% Energy Flux Upper Limit = 4.35e-9 erg/s/cm^2
95% Energy Fluence Upper Limit = 1.74e-06 erg/cm^2
Extended Emission Interval 2 (T0 to T0+400s):
95% Energy Flux Upper Limit = 4.13e-9 erg/s/cm^2
95% Energy Fluence Upper Limit = 1.65e-066 erg/cm^2
Furthermore, the upper limit on the ratio between the 0.1-300 GeV to
8-1000 keV fluence (HE/LE) for the T0 to T0+8.1s interval is 0.14.
The upper limit results presented above are preliminary. The Fermi LAT
is a pair conversion telescope designed to cover the energy band from
20 MeV to greater than 300 GeV. It is the product of an international
collaboration between NASA and DOE in the U.S. and many scientific
institutions across France, Italy, Japan and Sweden.
- GCN Report 261.1
GCN_Report 261.1 has been posted:
http://gcn.gsfc.nasa.gov/reports/report_261_1.pdf
by R. Margutti
at INAF-OAB and U. Biocca
titled: "Swift Observations of the AGILE burst GRB 091010"
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