- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 24 Sep 04 11:52:15 UT
NOTICE_TYPE: HETE S/C_Alert
TRIGGER_NUM: 3564, Seq_Num: 1
GRB_DATE: 13272 TJD; 268 DOY; 04/09/24
GRB_TIME: 42731.37 SOD {11:52:11.37} UT
TRIGGER_SOURCE: Trigger on the 6-80 keV band.
GAMMA_RATE: 518 [cnts/s] on a 0.160 [sec] timescale
SC_LONG: 222 [deg East]
SUN_POSTN: 181.62d {+12h 06m 30s} -0.70d {-00d 42' 14"}
MOON_POSTN: 313.28d {+20h 53m 07s} -22.90d {-22d 54' 07"}
MOON_ILLUM: 81 [%]
COMMENTS: No s/c ACS pointing info available yet.
COMMENTS: Probable GRB.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 24 Sep 04 11:52:25 UT
NOTICE_TYPE: HETE S/C_Update
TRIGGER_NUM: 3564, Seq_Num: 2
GRB_DATE: 13272 TJD; 268 DOY; 04/09/24
GRB_TIME: 42731.37 SOD {11:52:11.37} UT
TRIGGER_SOURCE: Trigger on the 6-80 keV band.
GAMMA_RATE: 518 [cnts/s] on a 0.160 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 0 [deg]
SC_LONG: 222 [deg East]
WXM_CNTR_RA: 31.584d {+02h 06m 20s} (J2000),
31.649d {+02h 06m 36s} (current),
30.902d {+02h 03m 37s} (1950)
WXM_CNTR_DEC: +16.177d {+16d 10' 39"} (J2000),
+16.200d {+16d 11' 59"} (current),
+15.939d {+15d 56' 22"} (1950)
WXM_MAX_SIZE: 28.00 [arcmin] diameter
WXM_LOC_SN: 8 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 6.2 Y= 6.0 [sig/noise]
WXM_LC_SN: X= 10.2 Y= 8.2 [sig/noise]
SUN_POSTN: 181.62d {+12h 06m 30s} -0.70d {-00d 42' 14"}
SUN_DIST: 146.60 [deg]
MOON_POSTN: 313.28d {+20h 53m 07s} -22.90d {-22d 54' 07"}
MOON_DIST: 86.00 [deg]
MOON_ILLUM: 81 [%]
GAL_COORDS: 147.88,-43.04 [deg] galactic lon,lat of the burst
ECL_COORDS: 34.97,3.18 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 24 Sep 04 11:52:31 UT
NOTICE_TYPE: HETE S/C_Update
TRIGGER_NUM: 3564, Seq_Num: 3
GRB_DATE: 13272 TJD; 268 DOY; 04/09/24
GRB_TIME: 42731.37 SOD {11:52:11.37} UT
TRIGGER_SOURCE: Trigger on the 6-80 keV band.
GAMMA_RATE: 518 [cnts/s] on a 0.160 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 0 [deg]
SC_LONG: 222 [deg East]
WXM_CNTR_RA: 31.666d {+02h 06m 40s} (J2000),
31.730d {+02h 06m 55s} (current),
30.984d {+02h 03m 56s} (1950)
WXM_CNTR_DEC: +16.136d {+16d 08' 10"} (J2000),
+16.158d {+16d 09' 30"} (current),
+15.898d {+15d 53' 53"} (1950)
WXM_MAX_SIZE: 28.00 [arcmin] diameter
WXM_LOC_SN: 5 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 4.2 Y= 4.0 [sig/noise]
WXM_LC_SN: X= 7.7 Y= 5.7 [sig/noise]
SUN_POSTN: 181.62d {+12h 06m 30s} -0.70d {-00d 42' 14"}
SUN_DIST: 146.54 [deg]
MOON_POSTN: 313.28d {+20h 53m 07s} -22.90d {-22d 54' 07"}
MOON_DIST: 86.05 [deg]
MOON_ILLUM: 81 [%]
GAL_COORDS: 148.00,-43.04 [deg] galactic lon,lat of the burst
ECL_COORDS: 35.03,3.12 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 24 Sep 04 11:52:40 UT
NOTICE_TYPE: HETE S/C_Update
TRIGGER_NUM: 3564, Seq_Num: 4
GRB_DATE: 13272 TJD; 268 DOY; 04/09/24
GRB_TIME: 42731.37 SOD {11:52:11.37} UT
TRIGGER_SOURCE: Trigger on the 6-80 keV band.
GAMMA_RATE: 518 [cnts/s] on a 0.160 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 0 [deg]
SC_LONG: 222 [deg East]
WXM_CNTR_RA: 31.576d {+02h 06m 18s} (J2000),
31.640d {+02h 06m 34s} (current),
30.894d {+02h 03m 35s} (1950)
WXM_CNTR_DEC: +16.163d {+16d 09' 48"} (J2000),
+16.186d {+16d 11' 09"} (current),
+15.925d {+15d 55' 31"} (1950)
WXM_MAX_SIZE: 28.00 [arcmin] diameter
WXM_LOC_SN: 13 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 10.0 Y= 9.5 [sig/noise]
WXM_LC_SN: X= 15.7 Y= 14.7 [sig/noise]
SUN_POSTN: 181.62d {+12h 06m 30s} -0.70d {-00d 42' 14"}
SUN_DIST: 146.61 [deg]
MOON_POSTN: 313.28d {+20h 53m 07s} -22.90d {-22d 54' 07"}
MOON_DIST: 85.99 [deg]
MOON_ILLUM: 81 [%]
GAL_COORDS: 147.88,-43.05 [deg] galactic lon,lat of the burst
ECL_COORDS: 34.96,3.17 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 24 Sep 04 11:59:46 UT
NOTICE_TYPE: HETE S/C_Last
TRIGGER_NUM: 3564, Seq_Num: 5
GRB_DATE: 13272 TJD; 268 DOY; 04/09/24
GRB_TIME: 42731.37 SOD {11:52:11.37} UT
TRIGGER_SOURCE: Trigger on the 6-80 keV band.
GAMMA_RATE: 518 [cnts/s] on a 0.160 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 0 [deg]
SC_LONG: 222 [deg East]
WXM_CNTR_RA: 31.576d {+02h 06m 18s} (J2000),
31.640d {+02h 06m 34s} (current),
30.894d {+02h 03m 35s} (1950)
WXM_CNTR_DEC: +16.163d {+16d 09' 48"} (J2000),
+16.186d {+16d 11' 09"} (current),
+15.925d {+15d 55' 31"} (1950)
WXM_MAX_SIZE: 28.00 [arcmin] diameter
WXM_LOC_SN: 13 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 10.0 Y= 9.5 [sig/noise]
WXM_LC_SN: X= 15.7 Y= 14.7 [sig/noise]
SUN_POSTN: 181.62d {+12h 06m 30s} -0.70d {-00d 42' 14"}
SUN_DIST: 146.61 [deg]
MOON_POSTN: 313.28d {+20h 53m 07s} -22.90d {-22d 54' 07"}
MOON_DIST: 85.99 [deg]
MOON_ILLUM: 81 [%]
GAL_COORDS: 147.88,-43.05 [deg] galactic lon,lat of the burst
ECL_COORDS: 34.96,3.17 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN notice #2734
D.B. Fox and D.-S. Moon report on behalf of a larger collaboration:
"We have imaged the localization region of GRB040924 (HETE Trigger
3564) with the robotic Palomar 60-inch telescope and CCD imager in the
R-band. Comparison of a subset of these images to the digitized sky
survey reveals the presence of a new, bright, stationary source that
shows evidence of variability over the span of our observations. The
coordinates of the source relative to the GSC-2.2 are:
RA 02:06:22.45, Dec +16:06:48.72 (J2000)
where the uncertainty in these coordinates is less than 2 arcsec. The
source has R>~17 in our images."
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 24 Sep 04 13:24:19 UT
NOTICE_TYPE: HETE Ground Analysis
TRIGGER_NUM: 3564, Seq_Num: 6
GRB_DATE: 13272 TJD; 268 DOY; 04/09/24
GRB_TIME: 42731.36 SOD {11:52:11.36} UT
TRIGGER_SOURCE: Trigger on the 6-80 keV band.
GAMMA_RATE: 518 [cnts/s] on a 0.160 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 0 [deg]
SC_LONG: 222 [deg East]
WXM_CNTR_RA: 31.581d {+02h 06m 19s} (J2000),
31.646d {+02h 06m 35s} (current),
30.899d {+02h 03m 36s} (1950)
WXM_CNTR_DEC: +16.024d {+16d 01' 26"} (J2000),
+16.046d {+16d 02' 47"} (current),
+15.786d {+15d 47' 09"} (1950)
WXM_MAX_SIZE: 12.80 [arcmin] diameter
WXM_LOC_SN: 13 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 10.0 Y= 9.5 [sig/noise]
WXM_LC_SN: X= 15.7 Y= 14.7 [sig/noise]
SUN_POSTN: 181.62d {+12h 06m 30s} -0.70d {-00d 42' 14"}
SUN_DIST: 146.66 [deg]
MOON_POSTN: 313.28d {+20h 53m 07s} -22.90d {-22d 54' 07"}
MOON_DIST: 85.93 [deg]
MOON_ILLUM: 81 [%]
GAL_COORDS: 147.96,-43.18 [deg] galactic lon,lat of the burst
ECL_COORDS: 34.92,3.04 [deg] ecliptic lon,lat of the burst
COMMENTS: Definite GRB.
COMMENTS: WXM error box is circular; not rectangular.
COMMENTS: Burst_Validity flag is true.
COMMENTS: WXM data refined since S/C_Last Notice.
- red DSS finding chart (6.4 arcmin radius)
ps-file
- GCN notice #2735
GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
E. E. Fenimore, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley,
on behalf of the HETE Science Team;
T. Donaghy, M. Galassi, C. Graziani, M. Matsuoka, Y. Nakagawa,
T. Sakamoto, R. Sato, Y. Shirasaki, M. Suzuki, T. Tamagawa, Y. Urata,
T. Yamazaki, Y. Yamamoto, and A. Yoshida, on behalf of the HETE WXM Team;
N. Butler, G. Crew, J. Doty, A. Dullighan, G. Prigozhin, R. Vanderspek,
J. Villasenor, J. G. Jernigan, A. Levine, G. Azzibrouck, J. Braga,
R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and
HETE Optical-SXC Teams;
C. Barraud, M. Boer, J-F Olive, J-P Dezalay, and K. Hurley, on behalf of
the HETE FREGATE Team;
report:
The HETE Fregate and WXM instruments detected GRB 040924 (=H3564) at
11:52:11 UT (42731 SOD) on 24 September 2004. The WXM flight software
localized the burst in real time, resulting in a GCN Notice 14 seconds
after the burst trigger. The flight error region was a circle of
14 arcminutes radius (90% confidence) centered at
RA = 02h 06m 40s, DEC = +16d 08' 10" (J2000).
Ground analyses of the burst data allow the error region to be refined
to a circle of 6.4 arcminutes radius (90% confidence) centered at
RA = 02h 06m 19s, DEC = +16d 01' 26" (J2000).
The burst is short, although not particularly hard: the burst durations,
as measured by T50, are 1.2s, 1.0s, and 0.6s in the 7-30 keV, 7-80 keV,
and 30-400 keV bands, respectively. Preliminary spectral analyses show
GRB 040924 to have an Epeak of 42 +/- 6 keV. The 7-30 keV fluence is
1.6e-6 erg/cm2, and the 30-400 keV fluence is 2.6e-6 erg/cm2: the fluence
ratio is 0.6, allowing us to classify GRB 040924 as an X-ray rich GRB.
The empirical redshift indicator ("pseudo-z"; Atteia 2003) for GRB 040924
is 0.5.
This message may be cited.
- GCN notice #2736
K. Hurley and T. Cline, on behalf of the Ulysses, HETE, and Mars
Odyssey GRB teams,
I. Mitrofanov, S. Charyshnikov, V. Grinkov, A. Kozyrev, M. Litvak, and
A. Sanin, on behalf of the HEND-Odyssey GRB team,
W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on
behalf of the GRS-Odyssey GRB team, and
E. E. Fenimore, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, S. Woosley,
T. Donaghy, M. Galassi, C. Graziani, M. Matsuoka, Y. Nakagawa, T.
Sakamoto, R. Sato, Y. Shirasaki, M. Suzuki, T. Tamagawa, Y. Urata, T.
Yamazaki, Y. Yamamoto, A. Yoshida, N. Butler, G. Crew, J. Doty, A.
Dullighan, G. Prigozhin, R. Vanderspek, J. Villasenor, J. G. Jernigan,
A. Levine, G. Azzibrouck, J. Braga, R. Manchanda, G. Pizzichini, C.
Barraud, M. Boer, J-F Olive, and J-P Dezalay, on behalf of the HETE GRB
team, report:
This burst (H3564, GCN 2735) was observed by Mars Odyssey (HEND). Ulysses was
off. We have triangulated it to a preliminary annulus centered RA,
Decl. (2000)=359.188, -1.351 degrees, whose radius is 36.408 +/- 0.044
degrees (3 sigma). This annulus intersects the HETE WXM error circle at the
following points:
RA(2000) Decl.(2000)
31.630 +16.037
31.531 +16.236
31.528 +16.038
31.467 +16.159
The joint IPN/WXM error box has an area of ~70 sq. arcmin.;
the candidate optical counterpart reported by Fox and Moon
(GCN 2734) lies just at the outer edge of this error box.
A map will be posted shortly at
http://www.ssl.berkeley.edu/ipn3/040924.
- GCN notice #2737
V. Lipunov, A.Krylov, V.Kornilov, G.Borisov, D.Kuvshinov, A.Belinski,
M.Kuznetsov, S.Potanin, G.Antipov, E.Gorbovskoy, N.Tyurina
Sternberg Astronomical Institute, Alexsandr Krylov Observatory, Moscow
At 5h 21m after HETE alert 3564 MASTER robotic telescope
(http://observ.pereplet.ru)
had imaging the corresponding area of the
sky under the large zenit distance.
The first image was started at 17h13m34s UT.
Now we have 15 unfiltered images of the error box (45s exposition, 40 x 50
arcmin, 200 mm camera).
Ther is no optical transient up to 17.5 m on all images and at position
given Fox and Moon (GCN2734).
Our unfiltred magnitude close to R filter.
Sum FITS image are available at
http://observ.pereplet.ru/images/GRB040924/
This message may be cited.
- GCN notice #2738
V. Lipunov, A.Krylov, V.Kornilov, G.Borisov, D.Kuvshinov, A.Belinski,
M.Kuznetsov, S.Potanin, G.Antipov, E.Gorbovskoy, N.Tyurina
Sternberg Astronomical Institute, Alexsandr Krylov Observatory, Moscow
At 5h 21m after HETE alert 3564 MASTER robotic telescope
(http://observ.pereplet.ru) had imaging the corresponding area of the
sky under the large zenit distance (GCN 2737).
The first image was started at 17h13m34s UT.
Now we have 50 unfiltered images of the error box (45s exposition, 40 x 50
arcmin, 200 mm camera).
Ther is no optical transient up to 18.5 m at position
given Fox and Moon (GCN2734).
Our unfiltered magnitude is close to R filter.
So, we conclude that OT proposed by Fox and Moon can be real optical
emission from GRB040929.
Sum FITS image are available at
http://observ.pereplet.ru/images/GRB040924/
This message may be cited.
- GCN notice #2739
D. P=E9rez-Ram=EDrez (Univ. de Ja=E9n), P. Tristram (Univ. of Canterbury),
J. Gorosabel, M. Jel=EDnek (IAA-CSIC, Granada), Ch. Okada (Nagoya
Univ.), Ph. Yock (Univ. of Auckland), A. de Ugarte Postigo, S. Guziy
and A. J. Castro-Tirado (IAA-CSIC)
report:
Following the detection by HETE-2 of the short/soft GRB 040924
(Fenimore et al. GCN Circ. 2735) we imaged the error box with
the 0.6 m telescope at Mt. John Observatory (+ MOA camera)
in the wide R-band filter. A 300-s single image was obtained
through clouds starting on Sep 24, 13:53 UT (2.0 hr after the
event). Additional images (3 x 300-s) were obtained at high airmass
under clear sky conditions, about 5 hr after the GRB onset. At the
position of the optical counterpart proposed by Fox and Moon
(GCN Circ. 2734) we do not see any optical source down to about
R =3D 19 and R =3D 20.5 at these two epochs. If this is the true optical
counterpart, the fast decay would resemble the one of the proposed
counterpart for the short/hard GRB 000313 as detected by BOOTES
(Castro-Tirado et al. 2002, A&A 393, L55). A more in-depth analysis
of the images is in progress.
This message can be quoted.
- GCN notice #2740
I. Khamitov, Z. Aslan (TUG), C. Yesilyaprak (AkUni), U. Kiziloglu (METU),
A. Alpar (SabUni), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), I. Bikmaev,
N. Sakhibullin (KGU)
report:
We observed the error box of GRB 040924 (Fenimore et al., GCN 2735) with
Russian-Turkish 1.5-m telescope (Bakyrlytepe, TUBITAK National Observatory,
Turkey). We made a set of 300s exposures in R, starting at 20:50 UT,
i.e. approximately 9 hours after the burst. Near the position of the OT
given by Fox and Moon (GCN 2734) we detected a faint object, m_R=~22.1.
Its coordinates:
02:06:22.56 +16:06:48.4 (2000.0)
Astrometry was done using UCAC2 catalog, the accuracy is 0.1 arcsec.
The object seems to be extended, therefore the host galaxy may contribute
a significant fraction of the flux of this source. We will continue
our observations in order to detect its possible fading behavior.
This message may be cited.
- GCN notice #2741
D.B. Fox (Caltech) reports on behalf of a larger collaboration:
"Further analysis of our Robotic P60 observations of the candidate
optical afterglow of GRB040924 (GCNs 2734, 2735) reveals that the
candidate afterglow fades by 0.87 +/- 0.08 mag from our first exposure
(mean epoch 12:07:57 UT) to our last exposure (mean epoch 12:42:09
UT). Referenced to the time of the burst this corresponds to a decay
with power-law index alpha approximately equal to -0.7.
The coordinates of the candidate referenced to the GSC-2.2 are:
RA 02:06:22.55, Dec +16:06:48.8 (J2000)
with coordinate uncertainties of approximately 0.2".
Photometric calibration of the data against the F-emulsion magnitudes
of the GSC-2.2 yields an R-band magnitude of the candidate at our
first epoch (945 sec after the burst) of R=18.0 mag.
Images and a finding chart for the candidate may be found at:
http://www.astro.caltech.edu/~derekfox/grb040924/
- GCN notice #2742
H. Terada and M. Akiyama (Subaru Telescope, NAOJ) report:
"We observed the field of the optical afterglow candidate (Fox and
Moon, GCN 2734) of GRB 040924 (=H3564, Fenimore et al., GCN 2735) in
the K'-band with IRCS on the 8.2m Subaru Telescope at 14:12-14:23 UT
on September 24 (2.4 hours after the burst).
At the position of the OT candidate, we detected a source
with magnitude K'= 17.5."
- GCN notice #2743
GRB040924 : Optical candidate observations at Lulin observatory
J.H. Hu, H.C. Lin (NCU)
K.Y. Huang, Y. Urata, W.H. Ip, T. Tamagawa=20
on behalf of Lulin GRB collaboration report:
We have observed the optical candidate of GRB040924 reported by Fox
et al. (GCN 2734) with 1-m telescope at Lulin Observatory ( National
Central University, Taiwan). We made B, V, R and I-band imaging
observations starting at 14.31 UT (2.3 hrs after the burst). =20
Based on our preliminary analysis, the optical candidate was
detected. The position of the candidate referenced to the USNO-B1.0
are=20
RA =3D 02:06:22.52, Dec =3D 16:06:48.5 (J2000)
with uncertainties of approximately 0.2".=20
The R-band magnitude at 18.67 UT (6.7 hrs after the burst) is 21.4
mag. compared with near USNO-B1.0 stars as photometric references.
Further analysis are in progress."
- GCN notice #2744
GRB040924 : Optical candidate observations at Lulin observatory
J.H. Hu, H.C. Lin (NCU)
K.Y. Huang, Y. Urata, W.H. Ip, T. Tamagawa
on behalf of Lulin GRB collaboration report:
We apologize to send multi-part mesage at last report (GCN 2743).
We submit our report again.
We have observed the optical candidate of GRB040924 reported by Fox
et al. (GCN 2734) with 1-m telescope at Lulin Observatory ( National
Central University, Taiwan). We made B, V, R and I-band imaging
observations starting at 14.31 UT (2.3 hrs after the burst).
Based on our preliminary analysis, the optical candidate was
detected. The position of the candidate referenced to the USNO-B1.0
are
RA = 02:06:22.52, Dec = 16:06:48.5 (J2000)
with uncertainties of approximately 0.2".
The R-band magnitude at 18.67 UT (6.7 hrs after the burst) is 21.4
mag. compared with near USNO-B1.0 stars as photometric references.
Further analysis are in progress."
This message maybe cited.
- GCN notice #2745
H. Terada, M. Akiyama (Subaru Telescope, NAOJ) and N. Kawai (Tokyo
Tech) report:
"The finding chart based on the the K' band image of the Subaru IRCS
observation (GCN 2742) is available at
http://www.hp.phys.titech.ac.jp/nkawai/grb/040924/.
The accuracy of the photometry (K'=17.5) is about 0.1 mag, as
estimated from the scatter of photometric values for the OT in eight
independent frames. "
- GCN notice #2746
A.J. van der Horst (University of Amsterdam), E. Rol (University of
Leicester) and R.A.M.J. Wijers (University of Amsterdam) report on behalf
of a larger collaboration:
"We observed the position of the GRB 040924 afterglow at 4.9 GHz with the
Westerbork Synthesis Radio Telescope at September 25, 0.41 - 7.36 UT, i.e.
12.54 - 19.49 hours after the burst (GCN 2735). We do not detect a radio
source at the position of the optical afterglow (GCN 2734), with a 3 sigma
upper limit of 0.12 mJy."
This message may be cited.
- GCN notice #2747
J. P. U. Fynbo (U. Copenhagen), A. Hornstrup (DSRI), J. Hjorth (U.
Copenhagen), B. L. Jensen (U. Copenhagen), Michael I. Andersen (AIP)
report on behalf or a larger collaboration:
"We have observed the afterglow of GRB 040924 (Fenimore et al. GCN
#2735; Fox et al. GCN #2734, GCN #2741) with the 2.56-m Nordic Optical
Telescope on La Palma. By stacking 9 300sec exposures in the R-band with
a mean epoch of Sep 25 5.25 UT we detect a source at the position of the
candidate afterglow reported by Fox et al. Assuming a magnitude of
R=19.1 for the nearby star U1050_00580520 we estimate that the afterglow
flux is around R=22.1 17.5 hours after the burst. This implies the the
lightcurve has become steeper than the slope of -0.7 during the first
hour reported by Fox et al. (GCN #2741)."
[GCN OPS NOTE: This circular was delayed 1.6 hr due to a change in the submiter's
email domain.]
- GCN notice #2748
W. Li, A. V. Filippenko, R. Chornock, and S. Jha (University of
California, Berkeley) report:
"The Katzman Automatic Imaging Telescope (KAIT; see Li et al. 2003,
PASP, 115, 844) at Lick Observatory robotically observed GRB 040924
(HETE Trigger #3564). Three batches of observations (a total of 34
images) were taken during the first 100 minutes after the burst. Our
first exposure began at 11:52:55 UT, only 44 seconds after burst.
Unfortunately, owing to the relatively small field of view of KAIT
(6.7' x 6.7'), the OT reported by Fox and Moon (GCN 2734) was slightly
outside our field of view in this image and in most of the subsequent
images. The OT was detected only in two sets of images taken during
our 2 x 2 mosaic procedure. From a 120 s unfiltered exposure that
started at 12:18:21 UT, we measured a magnitude of 18.3 (USNO-A2.0
red mag calibrations) for the OT. The object declined to mag 19.2
in a 120 s image that started at 12:55:21 UT. Referenced to the
time of the burst, this corresponds to a decay with power-law index
alpha approximately equal to -1.0.
We also obtained six 300 s KAIT unfiltered images (with the mean
epoch at 8:50 UT) of GRB 040924 on Sep 25 UT. We did not detect
the OT in the combined image, which has a 3-sigma limit of about
mag 22.5."
- GCN notice #2749
I. Khamitov, Z. Aslan (TUG), C. Yesilyaprak (Akdeniz Univ.), U. Kiziloglu (METU),
E. Gogus, A. Alpar (Sabanci Univ.), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
I. Bikmaev, N. Sakhibullin (KSU)
report:
We observed the error box of GRB 040924 (Fenimore et al., GCN 2735) with
Russian-Turkish 1.5-m telescope (Bakyrlytepe, TUBITAK National Observatory,
Turkey). During continuous observations of the afterdlow candidate from
Sep. 24, 20:50UT to Sep. 25, 02:40UT (8.96--14.94 hours after the burst)
we obtained 64x300s images in R. The observations were made under moderate
atmospheric conditions.
We found that the afterglow candidate (Fox and Moon, GCN 2734) faided by
approximately 0.6 mag, from m_R=22.1 to 22.7, during our observations,
which corresponds to power law decay with index -1.16.
The absolute calibration was done according our mean photometric
solutions. For comparison one can use star at 02:06:23.3 +16:07:13 wich
has m_R=19.8 according to our solutions. Brighter magnitide, reported by
Fynbo et al. (GCN 2747) most likely is due to the difference in absolute
calibration.
Our light curve can be found at:
http://hea.iki.rssi.ru/~rodion/040924/lc_0924.jpg
This message may be cited
- GCN notice #2750
H. Terada, M. Akiyama (Subaru Telescope, NAOJ) and N. Kawai (Tokyo
Tech) report:
"We have made the second epoch observation of the afterglow candidate
(GCN 2734) of GRB 040924 (=H3564, GCN 2735) in the K'-band with IRCS
on the 8.2m Subaru Telescope at 15:07-15:41 UT on September 25 (27.5
hours after the burst) for an integration time of 1200 seconds with an
average seeing of 0.52 arcsec.
At the position of the afterglow, we detected an extended source with
magnitude K'=20.4 +/- 0.2. It is probably the afterglow of GRB 040924
with a significant contribution from its host galaxy. Comparison with
the earlier flux (K'=17.5 at t=2.4 hr, Terada and Akiyama, GCN 2742)
imply that the NIR afterglow decay index was steeper than -1.
The image is available at
http://www.hp.phys.titech.ac.jp/nkawai/grb/040924/"
- GCN notice #2751
E.Sonoda,S.Maeno,Y.Matsuo,M.Yamauchi
(University of Miyazaki)
"We have observed the field covering the error box of
GRB040924 (HETE trigger 3564; trigger time 11:52:11 UT)
with unfiltered CCD camera on the 30-cm telescope at
University of Miyazaki.The observation was started
15:53:50 UT on Sep.24.
Observed field of view is 43 arcmin centerd on
R.A.= 02h 06m 56.75s , Dec.= +16d 07m 27.5s,and include
the position given by D.B.Fox and D.-S.Moon (GCN 2734).
After co-adding a set of 3 images of 30 sec exposures,
we have compared with the USNO A2.0 catalog. Preliminary
analysis shows there is no new sorce brighter than 16.6 mag."
- GCN notice #2752
I. Khamitov, Z. Aslan (TUG), C. Yesilyaprak (Akdeniz Univ.),
U. Kiziloglu (METU), E.Gogus, A. Alpar (Sabanci Univ.),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
I. Bikmaev, N. Sakhibullin (KSU)
report:
We observed the afterglow of GRB 040924 (Fenimore et al. GCN 2735, Fox
and Moon, GCN 2734) with Russian-Turkish 1.5-m telescope (Bakyrlytepe,
TUBITAK National Observatory, Turkey). We made 33x300s images in R between
Sep. 25, 23:45 UT, and Sep. 26, 2:45 UT. The observations were hampered by
the bright-moon and bad seeing (1.7 arcsec). The object was clearly
detected near the limit of the combined image. We estimate its magnitude
to be m_R=23.7+/-0.2.
This magnitude is consistent with power law decay with index -1.16,
obtained in our previous observations (GCN 2749). The KAIT earlier
measurements (GCN 2748) seem to be consistent with this power law as well.
Therefore, to the first approximation, the whole light curve of the GRB
040924 afterglow can be described as a single power law with index -1.16.
The combined light curve can be found at:
http://hea.iki.rssi.ru/~rodion/040924/lc_all.jpg
or
http://www.tug.tubitak.gov.tr/~irekk/grb/grb040924/lc_all.jpeg
The finding charts:
http://hea.iki.rssi.ru/~rodion/040924/fcharts.html
or
http://www.tug.tubitak.gov.tr/~irekk/grb/grb040924/fcharts.html
This message may be cited.
- GCN notice #2753
E. Pavlenko, S. Sergeev, V.Rumyantsev (CrAO), A.Pozanenko (IKI) report:
We observed the field of the optical afterglow candidate (Fox and Moon, GCN
2734) of GRB 040924 (=H3564, Fenimore et al., GCN 2735) in the R (Johnson)
band with APOGEE 47 on the 38-cm Cassegrain telescope of the Crimean
Astrophysical Observatory.
The observations were started at Sep. 24, 20:21 UT (i.e. 8.48 hours after
the burst) and continued up to Sep.24, 23.13 UT. The sum of the first 3
images
(3x190-s) yield the limiting magnitude 19.7 +- 0.2. No optical counterpart
at the position proposed by Fox and Moon was found. For the sum of last
7x240 images taken between Sep. 24 23:08 - 23:46 UT no counterpart fainter
than 21.0 +- 0.2 was detected. The limiting magnitudes were estimated in
comparison of the USNO-B1.0 stars as photometric sequences. The limits are
in agreement with OT magnitude estimation in simultaneous observation of
I.Khamitov et al. (GCN 2749).
This message may be cited.
- GCN notice #2754
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks
on behalf of Konus-Wind and Helicon/Coronas-F teams,
T. Cline on behalf of the Konus-Wind team, report:
A soft short GRB040924 (=H3564, GCN 2735) was detected by Konus-Wind
at 11.52.15.280 UT and Helicon-Coronas-F at 11:52:12.691 UT.
It had a duration of approximately 1.5s in the 20-300 keV band.
As observed by Konus-Wind it had
a 20-500 keV fluence of (2.73 +/- 0.12)E-6 erg/cm2,
a 20-500 keV peak flux (3.33 +/- 0.35)E-6 erg/cm2 s over 0.064 s,
and Epeak of the time-integrated spectrum of 67 +/- 6 keV.
We have triangulated it to an annulus:
RA(2000) = 339.625 deg,
Decl(2000) = -5.584 deg,
Radius = 56.049 +/- 1.038 degrees (3 sigma).
This annulus encompasses the HETE WXM error circle reported in GCN 2735.
The center of the annulus passes 0.29 deg (0.84 sigma) from the center
of HETE error circle and 0.25 deg (0.7 sigma) from the position of
the OT given by Fox and Moon (GCN 2734).
- GCN notice #2758
D. A. Frail (NRAO) and A. M. Soderberg (Caltech) report on behalf of a
larger collaboration:
"On 2004 Sept. 30.28 UT we used the VLA to observe a field centered on
the candidate optical afterglow (GCN 2734) of GRB040924 (GCN 2735).
There are no radio sources at 8.46 GHz in the vicinity down to
a 3-sigma limit of 147 microJy.
Further observations are planned."
- GCN notice #2759
A.J. van der Horst (University of Amsterdam), E. Rol (University of
Leicester) and R.A.M.J. Wijers (University of Amsterdam) report on behalf
of a larger collaboration:
"We reobserved the position of the GRB 040924 afterglow at 4.9 GHz with
the Westerbork Synthesis Radio Telescope from September 29 19.06 UT to
September 30 6.81 UT, i.e. 5.30 - 5.79 days after the burst (GCN 2735).
The rms noise in het map around that position is 30 microJy per beam. The
formal flux measurement for a point source at the location of the optical
afterglow (GCN 2734) is 11 +/- 30 microJy.
In conclusion, we do not detect a source at the optical position, in
agreement with our previous WSRT measurements (GCN 2746) and the VLA
measurements (GCN 2758).
No further observations are planned."
This message may be cited.
- GCN notice #2800
Klaas Wiersema (University of Amsterdam), Rhaana L.C. Starling
(University of Amsterdam), Evert Rol (University of Leicester),
Paul Vreeswijk (ESO), Ralph A.M.J. Wijers (University of Amsterdam)
report on behalf of the GRACE collaboration:
"We have obtained two spectra of the host galaxy of GRB 040924
(GCN #2735, 2734) with the FORS2 long slit spectrograph on the
ESO VLT (Antu) on 10 October 2004, approx. 15.75 days after burst.
The first spectrum was taken at 05:10 UT using the 300V grism, with
an exposure time of 1800 s; the second spectrum was taken at 05:48 UT
using the 300I grism, again with an exposure time of 1800 s. We used
a 1 arcsec slit. The total wavelength range is approx. 400 - 950 nm.
We find weak emission lines in the spectra, which we identify with
[OII] 3727, [NeIII] 3968.9, H gamma, H beta and [OIII] 4959,5007.
All of these lines are consistent with a redshift z = 0.859.
The presence of [NeIII] implies a galaxy with a significant
population of massive stars. The isotropic energy of the burst is
E_iso=1.48x10^52 erg, using the 25-100 keV fluence value from HETE
and a cosmology with H_0=70 km/s/Mpc, Omega_matter=0.3 and
Omega_lambda=0.7. As the lightcurve breaks fairly early on, the true
energy is likely to be much lower.
The presence of continuum features relating to a supernova
can only be determined after further analysis: a SN1998bw-like bump
would be expected to peak at approximately t_V~23.5 days, t_R~25 days and
t_I~26 days with magnitudes V~25.4, R~24.6 and I~23.8.
We acknowledge excellent support from the staff of Paranal Observatory
and ESO's PSO and USG."
- GCN notice #2811
A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:
We have acquired BVRcIc all-sky photometry for
a 11x11 arcmin field centered on the afterglow coordinates
(Fox and Moon, GCN 2734) for the HETE burst GRB040924
(trigger 3564; Fenimore et al., GCN 2735)
with the USNOFS 1.0-m telescope on one photometric
night. Stars brighter than V=14 are saturated and
should be used with care. We have placed the photometric data
on our anonymous ftp site:
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb040924.dat
The astrometry in this file is based on linear plate solutions
with respect to UCAC2. The external errors are less than 100mas.
The estimated external photometric error is about 0.03mag
and will be improved with additional calibration nights
later this week, weather permitting.
As always, you should check the dates on the .dat file prior to
final publication to get the latest photometry. There is
a README file on the ftp directory to give you information
about the procedures used to calibrate these fields.
- GCN notice #2833
J. Silvey, D. Allen, M. Bayliss, M. Nysewander, T. Tilleman, A. Henden, M.
Leake, A. Homewood, R. Canterna, D. Reichart, D. H. Hartmann, and M.
Schwartz report on behalf of the U. Wyoming, U. North Carolina, USNO, and
SARA GRB teams of the FUN GRB collaboration:
We observed the afterglow location (Fox & Moon, GCN 2734) of the short/soft
GRB 040924 (Fenimore et al., GCN 2735) in VRcIcH beginning 16.2 hours after
the burst. Using the field calibrations of Henden (GCN 2811) and 2MASS, we
report the following magnitudes:
Start Mean Time Filter Exposure Magnitude Telescope
Date Since GRB Time (sec) (1)
(hours) x Exposures
Sep 25.171 16.44 Rc 300 x 4 >18.9 0.9m SARA
Sep 25.191 16.89 Ic 300 x 4 >20.6 0.9m SARA
Sep 25.209 17.31 V 300 x 4 >19.6 0.9m SARA
Sep 25.228 18.32 H 800 x 4 >19.5 1.55m NOFS
Sep 25.328 21.18 Ic 300 x 24 >21.7 0.8m TII(2)
Sep 25.391 21.86 Rc 300 x 3 22.68+/-0.07 2.3m WIRO
Sep 25.395 21.96 V 300 x 3 23.06+/-0.07 2.3m WIRO
(1) Limiting magnitudes are 2 sigma.
(2) Tenagra II
Compared to the R observations of Fox (GCN 2741) and Pavlenko et al. (GCN
2753), our Rc observation is generally consistent with a temporal index of
approx. -1.
Assuming a temporal index of -1.16 (Khamitov et al., GCN 2749) and using
this index to scale our observations and the K' observation of Terada et
al. (GCN 2750) to 21.9 hours after the burst, and correcting for Galactic
extinction along the line of sight assuming that R_V = 3.1, yields a
spectral index of -0.61 +/- 0.08:
www.physics.unc.edu/~mbayliss/grbdata/grb040924spec.eps
If source-frame extinction is negligible, this is consistent with either a
constant-density or wind-swept medium with the cooling break blueward of
the observed bands. It is inconsistent with either a constant-density or
wind-swept medium with the cooling break redward of the observed bands
(e.g., Sari, Piran & Narayan 1998, ApJ, 497, L17; Chevalier & Li 2000; ApJ,
536, 195).
However, if source-frame extinction is non-negligible this is only
consistent with a wind-swept medium with the cooling break blueward of the
observed bands.
- 1002.3849 from 23 Feb 10
M. Arimoto et al.: Spectral Lag Relations in GRB Pulses Detected with HETE-2
T. Tamagawa, Y. Shirasaki, S. Sugita, I. Takahashi, J.-L. Atteia, A. Pelangeon, R. Vanderspek, C. Graziani, G. Prigozhin, J. Villasenor, J. G.
Jernigan, G. B. Crew, T. Sakamoto, G. R. Ricker, S. E. Woosley, N. Butler, A. Levine, J. P. Doty, T. Q. Donaghy, D. Q. Lamb, E. Fenimore, M.
Galassi, M. Boer, J.-P. Dezalay, J.-F. Olive, J. Braga, R. Manchanda, G. Pizzichini
Using a pulse-fit method, we investigate the spectral lags between the traditional gamma-ray band (50-400 keV) and the X-ray band (6-25 keV)
for 8 GRBs with known redshifts (GRB 010921, GRB 020124, GRB 020127, GRB 021211, GRB 030528, GRB 040924, GRB 041006, GRB 050408) detected with
the WXM and FREGATE instruments aboard the HETE-2 satellite. We find several relations for the individual GRB pulses between the spectral lag
and other observables, such as the luminosity, pulse duration, and peak energy (Epeak). The obtained results are consistent with those for
BATSE, indicating that the BATSE correlations are still valid at lower energies (6-25 keV). Furthermore, we find that the photon energy
dependence for the spectral lags can reconcile the simple curvature effect model. We discuss the implication of these results from various
points of view.
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