XRF 040912
GCN Circular 2797
Subject
Search for SN light in XRF 040912 with MEGACAM
Date
2004-10-12T15:18:08Z (21 years ago)
Edited On
2025-09-09T18:37:20Z (a month ago)
From
Jean-Luc Atteia at Lab d Astrophys.,OMP,Toulouse <atteia@ast.obs-mip.fr>
Edited By
courey.elliott@gmail.com
G. Stratta (OMP), F. Malacrino (OMP), M. Boer (OHP), A. Klotz (OMP), J-L Atteia (OMP), P. Martin (CFHT), C. Veillet (CFHT), J-C Cuillandre (CFHT) and Lisa Wells (CFHT) communicate:
We observed the HETE WXM error region of XRF 040912 (Butler et al. GCN 2701) with the wide-field imager MegaCam (36 2048 x 4612 pixel CCDs, 1 square degree FOV), mounted on the 3.6-m CFH Telescope.
Two exposures with integration time of 860s each, in the i' band have been performed consecutively starting on October 5.4197 UT (T_grb+22.8 days).
We looked for a possible SN emission for the 22 X-ray sources detected with Chandra
(Butler et al., GCN Circ=2716). The observation results follow:
First exposure (T) Second exposure (T+15min)
------ --------------------------- --------------------------
CXO Distance to i-band Distance to i-band
source X-ray position mag X-ray position mag
(") (")
------ --------------------------- --------------------------
#1 * 1.5 20.60 - -
#2 1.6 22.25 1.5 22.26
#3 1.4 20.17 1.5 20.20
#4 - - - -
#5 1.4 21.21 1.5 21.00
#6 1.5 18.96 1.3 18.99
#7 1.0 21.82 1.1 21.61
#8 1.8 23.02 1.3 23.09
#9 - - - -
#10 3.2 20.74 2.1 20.66
#11 1.0 21.68 0.9 22.44
#12 - - - -
#13 * - - 0.5 22.21
#14 1.2 21.84 1.6 21.39
#15 1.6 22.79 - -
#16 - - - -
#17 - - - -
#18 0.7 21.35 0.6 20.86
#19 - - - -
#20 - - - -
#21 - - - -
#22 - - - - --------------------------------------------------------------------
* Source was at the CCD line separation and was missed in one image
--------------------------------------------------------------------
We did not consider sources at distances greater than 2.5" from the
X-ray source position.
Our conclusions from these observations are:
1- If source #4 is the afterglow of XRF 040912 (as suggested in GCN 2731), we do not observed any SN emission down to i=23.2+/0.2 mag at 22.8 days after the burst event.
2- Source #13, which has been considered as the tentative afterglow of XRF 040912 (GCN 2728) does not appear to vary from the second Magellan observation.
We note that source #6 is coincident with an underlying galaxy with i'=19 mag, it has a decaying behavior in X-rays (Butler et al. GCN=2716) and shows the highest V-i' color index (V-i'=2.05, V magnitude reported by Gorosabel et al., GCN 2724), requiring a very red galaxy, or a rebrightning.
This resemble the case of XRF 040701 (Barraud et al. GCN 2620) for which the potentially associated Chandra source (Fox et al. GCN 2626) was coincident with a z=0.2146 emission-line galaxy (Kelson et al. GCN 2631) with lower limit R~17.9 mag that possibly prevented the observation of a delayed SN emission, assuming a SN fainter than SN 1998bw and more similar to SN2002ap or SN1994I (Pian et al. GCN 2638).
Further observations of source #6 are welcome.
A comparison of the two CFHT images that show the nearest objects to the
Chandra sources detected in the i' band, can be found at
http://www.cfht.hawaii.edu/~grb/XRF040912.html
GCN Circular 2733
Subject
XRF 040912: Radio Observations
Date
2004-09-23T15:59:42Z (21 years ago)
Edited On
2025-09-09T18:37:11Z (a month ago)
From
Alicia Soderberg at Caltech <ams@astro.caltech.edu>
Edited By
courey.elliott@gmail.com
A. M. Soderberg (Caltech) and D. A. Frail (NRAO) report on behalf of a
larger collaboration:
"On 2004 Sept. 23.24 UT we carried out follow-up observations with the
VLA at 8.46 GHz toward two positions centered on the X-ray afterglow
candidates (GCN 2716; GCN 2731) of XRF 040912 (GCN 2723). Within a
circle of 1-arcsec radius there are no radio sources toward either
X-ray candidate to a 3-sigma limit of 120 microJy.
No further observations are planned."
GCN Circular 2724
Subject
XRF 040912, identification of CXO sources
Date
2004-09-17T21:55:13Z (21 years ago)
Edited On
2025-09-09T18:37:04Z (a month ago)
From
Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es>
Edited By
courey.elliott@gmail.com
J. Gorosabel (IAC-CSIC Granada), J. Cepa (IAC
Tenerife), A. de Ugarte Postigo (IAA-CSIC),
D. Mart�nez-Delgado (MPIfA Heidelberg), V. Casanova,
S. Guziy, M. Jel�nek (IAA-CSIC, Granada), J. M.
Castro Cer�n (San Fernando), H. Castaneda (IAC
Tenerife), D. Zucker, E. F. Bell (AIP Potsdam)
and A. J. Castro-Tirado (IAA-CSIC)
report:
"We have acquired optical images covering the
entire error box of the XRF 040912 detected by
HETE-2 (Ricker et al. GCN Circ. 2701) starting
on 12 Sep 21:27 UT (i.e. 7.25 hr after the event).
The observations were performed with the 4.2m
WHT (+PFC) at La Palma (16'x 16' FOV).
The observing log follows:
-----------------------------------
Date 2004 UT Exp.Time (s) Filter
-----------------------------------
12 Sep 21:27:56 1455 B
12 Sep 21:53:45 900 V
13 Sep 04:26:41 900 V
13 Sep 21:07:58 1200 V
16 Sep 01:49:11 300 I
16 Sep 01:58:17 300 I
16 Sep 02:05:06 300 I
16 Sep 02:11:17 300 I
16 Sep 02:18:16 300 I
16 Sep 02:31:05 180 V
16 Sep 02:35:14 1200 V
----------------------------------
Additional images (I-band, 720-s) were also
taken at the 1.5m telescope at IAA Sierra
Nevada Observatory on 13 Sep (03:00 UT).
Internal comparison between the three V-band
frames did not reveal any optical variable
source in the entire HETE-2 error box. For
the 22 X-rays sources detected by the Chandra
X-ray Observatory (Butler et al., GCN Circ
2716) we detect the following optical
counterparts in the co-added V-band image
(3 sigma limiting magnitude = 25.1):
-------------------------------------
CXO V-band Distance to
source magnitude X-ray position (")
-------------------------------------
#1 21.6 2.0
#2 24.0 2.0
#3 21.1 2.0
#4 24.0 2.0
#5 21.9 1.4
#6 21.0 1.7
#7 22.9 1.7
#8 23.9 1.4
#9 23.9 1.8
#10 21.1 1.6
#11 23.0 1.4
#12 24.2 1.9
#13 23.6 0.5
#14* 23.9 0.9
22.7 1.8
#15 23.9 2.1
#16** >25.1 -
#17 24.5 2.0
#18 23.3 0.1
#19 >25.1 -
#20 >25.1 -
#21 >25.1 -
#22 >25.1 -
--------------------------------------
* Two possible counterparts
* V = 22.1 optical source at 3".5
--------------------------------------
Optical magnitudes are based on the calibration
provided by A. Henden (GCN Circ. 2720)."
This message can be quoted.
[GCN OPS NOTE (21sep04): The affiliation for
D. Martinez-Delgado from "AIP Potsdam" to
"MPIfA Heidelberg".]
GCN Circular 2723
Subject
XRF 040912 (=H3557): Spectral and Temporal Properties
Date
2004-09-17T20:17:03Z (21 years ago)
Edited On
2025-09-09T18:37:03Z (a month ago)
From
Don Lamb at U.Chicago <lamb@oddjob.uchicago.edu>
Edited By
courey.elliott@gmail.com
XRF 040912 (=H3557): Spectral and Temporal Properties
J-F Olive, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley,
on behalf of the HETE Science Team;
T. Donaghy, E. Fenimore, 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-P Dezalay, and K. Hurley, on behalf of the HETE
FREGATE Team;
report:
The burst-average photon number spectrum of GRB 040912 is best fit by
a power-law times exponential (PLE) model with a photon index alpha =
1.75 +0.28/-0.30 and a peak energy E_peak = 14.5 +/-14.5 keV.
The fluence of the burst is (8.3 +1.4/-1.3 ) x 10-7 erg cm-2 in the 2-30
keV energy band and (3.3 +2.9/-1.7) x 10-7 erg cm-2 in the 30-400 keV
energy band. The ratio of the fluences in the two energy bands is 2.5,
clearly making this burst an X-Ray Flash.
The T50 and T90 durations of XRF 040912 are 80 +/-5 sec and 127 +/-13
sec in the 6-40 keV energy band, and 81 +/-5 sec and 122 +/-7 sec in the
6-80 keV energy band, respectively.
This message may be cited.
GCN Circular 2720
Subject
XRF040912, BVRcIc field calibration
Date
2004-09-17T17:09:35Z (21 years ago)
Edited On
2025-09-09T18:36:58Z (a month ago)
From
Arne A. Henden at USNO/USRA <aah@nofs.navy.mil>
Edited By
courey.elliott@gmail.com
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 HETE coordinates
for GRB/XRF040912 (trigger 3557; Butler et al. GCN 2701)
with the USNOFS 1.0-m telescope on one photometric
night. Stars brighter than V=13.5 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/xrf040912.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
if an afterglow is discovered.
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 Circular 2709
Subject
GRB/XRF040912,optical observations
Date
2004-09-14T10:54:44Z (21 years ago)
Edited On
2025-09-09T18:36:54Z (a month ago)
From
Shouta Maeno at U.of Miyazaki <shouta@astro.miyazaki-u.ac.jp>
Edited By
courey.elliott@gmail.com
S.maeno,E.Sonoda,Y.Matsuo, M.Yamauchi
(University of Miyazaki)
We have observed the HETE-2 error circle of
GRB/XRF040912(HETE trigger 3557)with the unfiltered CCD camera
on the 30-cm telescope at University of Miyazaki.
Observed field of view is 43 arcmin centerd on (23h 57m 04s -00d 59' 12" ).
After co-adding a set of 8 images of 30 sec exposures, we have compared
our images with the USNO A2.0 catalog.
Preliminary analysis shows there is no new source brighter than
16.0mag. in our observed field at Sep 13, 12:09:30 UT.
GCN Circular 2707
Subject
Optical observations of GRB/XRF 040912 = HETE 3557
Date
2004-09-13T14:35:54Z (21 years ago)
Edited On
2025-09-09T18:36:52Z (a month ago)
From
Jens Hjorth at U.Copenhagen <jens@astro.ku.dk>
Edited By
courey.elliott@gmail.com
M. I. Andersen (AIP), M. Weidinger (U. Aarhus), J. Hjorth, J. P. U. Fynbo,
B. L. Jensen (U. Copenhagen) report:
"Using the ALFOSC at the 2.56-m Nordic Optical Telescope, La Palma, we have
obtained 2 x 2 mosaic CCD images covering the HETE-2 error circle of
GRB/XRF 040912 (Butler et al., GCNC 2701) on two epochs. Each pointing
consists of 3 x 300 sec in the R band.
Comparison of the two epochs (Sep 12.92-12.97 and Sep 13.19-13.24 2004 UT)
through visual inspection and difference imaging does not reveal any sources
exhibiting significant variability between the two epochs. The 3-sigma
variability limit is R ~ 23.4."