XRF 050509C
GCN Circular 3861
Subject
XRF050509c: Radio upper limits from GMRT
Date
2005-08-23T10:47:38Z (21 years ago)
Edited On
2026-04-24T17:51:40Z (6 months ago)
From
Atish Kamble at Raman Research Inst <atish@rri.res.in>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
Atish Kamble (Raman Research Institute [RRI], Bangalore, India),
C. H. Ishwara Chandra (NCRA, Pune, India) and D. Bhattacharya (RRI)
report on behalf of a larger GRB collaboration :
We observed the field of XRF 050509c (GCN 3402, GCN 3425, GCN 3543)
on Jul. 6.56 (UT) and on Aug 4.48 (UT) with the Giant Meterwave Radio
Telescope (GMRT), India at 1280 MHz using a bandwidth of 32 MHz.
We do not detect any source coincident with the position of radio
afterglow reported by Cameron and Soderberg (GCN 3543).
The two sigma upper limits are as follows:
Jul. 6.56 (UT) : 0.22 mJy
Aug 4.48 (UT) : 0.12 mJy
We thank GMRT and the National Centre for Radio Astrophysics (NCRA) staff.
This TOO was done under the GMRT Director's Discretionary Time.
GMRT is run by NCRA-TIFR, Pune (INDIA).
This messege may be cited.
GCN Circular 3546
Subject
XRF 050509c: Optical monitoring
Date
2005-06-14T09:43:49Z (21 years ago)
Edited On
2026-04-24T17:51:38Z (6 months ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
J. Gorosabel (IAA-CSIC), J. Hjorth, B. L. Jensen, U. G. Jørgensen (NBI),
J.-P. Beaulieu, A. Cassan (IAP), M. I. Andersen (AIP),
J. Donatowicz (Tech. Uni. of Vienna), D. Watson, J. P. U. Fynbo,
P. Jakobsson, J. M. Castro Cerón, H. Pedersen (NBI), report:
"We have performed almost daily R-band monitoring of the XRF 050509c
field (GCN Circ. 3402, HETE-2 trigger #3751) from May 15 to June 8.
No significant rebrightening brighter than R ~ 22.5 has been detected at
the afterglow position (GCN Circ. 3425) during the mentioned period.
If XRF 050509c was related to a supernova similar to SN 1998bw, our
observations would impose a lower redshift limit of z > 0.4.
A combination of all late images
(www.astro.ku.dk/~brian_j/grb/grb050509.95/)
reveals a faint (R ~ 24) object coincident with the afterglow position,
which we tentatively identify as the host galaxy of XRF 050509c."
GCN Circular 3543
Subject
XRF050509c: Radio Detection
Date
2005-06-10T16:21:34Z (21 years ago)
Edited On
2026-04-24T17:51:37Z (6 months ago)
From
Patrick B. Cameron at Caltech <pbc@astro.caltech.edu>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
P. B. Cameron and A. M. Soderberg (Caltech) report on behalf
of the Caltech-NRAO-Carnegie collaboration:
"We observed the field of XRF050509c (GCN 3402) with the
Very Large Array at 8.5 GHz on Jun 8.13 UT. At the position of
the optical afterglow (GCN 3425) we detect a radio source
with flux density 310 +- 49 uJy. Further observations are
planned."
GCN Circular 3442
Subject
XRF050509C: Chandra Afterglow Detection
Date
2005-05-20T18:09:04Z (21 years ago)
Edited On
2026-04-24T17:51:17Z (6 months ago)
From
Derek Fox at CIT <derekfox@astro.caltech.edu>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
Derek B. Fox (Caltech) reports on behalf of a larger collaboration:
"We have observed the afterglow (Gorosabel et al, GCN 3425) of XRF
050509C (Prigozhin et al., GCN 3402) with the Chandra X-ray
Observatory and ACIS-S detector, in a single 20-ks pointing beginning
at 09:54 UT on May 19, and detect the X-ray afterglow at a count rate
of 0.7(2) counts per ksec. This count rate corresponds to a 0.5-10
keV flux of 9E-15 erg cm-2 s-1, assuming a spectrum with power-law
photon index alpha=1.5 and Galactic N_H=5.5E+20 cm-2. We note that
this flux is consistent with the upper limit from Swift XRT at a
similar epoch (Campana et al., GCN 3441)."
GCN Circular 3441
Subject
XRF 050509c: Swift XRT Upper Limit
Date
2005-05-20T16:45:22Z (21 years ago)
Edited On
2026-04-24T17:51:16Z (6 months ago)
From
Sergio Campana at INAF-OAB <campana@merate.mi.astro.it>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
S. Campana (INAF-OAB), C. Pagani (INAF-OAB, PSU), D.N. Burrows (PSU)
and N. Gehrels (NASA/GSFC) report on behalf of the Swift XRT team:
The Swift XRT observed the HETE II burst XRF 050509c for ~4ks from
07:00 UT to 21:35 UT on 18 May 2005 and for ~19 ks from 00:18 UT to 23:25 UT
on 19 May 2005.
We did not detect any source in either observation in a 20
arcsec radius circle centred at the position of the optical counterpart
identified by Gorosabel et al 2005 (GCN 3425). Combining data from the two
observations, we obtain 23.1 ks of good data after normal data screening.
The 3 sigma upper limit on the count rate is of 8.4e-4 counts/s
(0.2-10.0 keV).
Assuming a Crab-like spectrum and a Galactic column of 7.1e20 cm-2, this
corresponds to an upper limit on the unabsorbed flux of ~3e-14
ergs/cm2/s (0.5-10.0 keV).
GCN Circular 3440
Subject
XRF050509c: Radio Observations
Date
2005-05-20T15:55:48Z (21 years ago)
Edited On
2026-04-24T17:51:14Z (6 months ago)
From
Alicia Soderberg at Caltech <ams@astro.caltech.edu>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
A. M. Soderberg (Caltech) and D. A. Frail (NRAO) report on behalf of
the Caltech-NRAO-Carnegie collaboration:
"We observed the field of XRF050509c (GCN 3402) with the Very Large
Array at 8.5 GHz on May 20.17 UT. We do not detect a radio source
coincident with the OT position (GCN 3425). We place a 2-sigma upper
limit of 104 uJy."
GCN Circular 3427
Subject
XRF 050509C: REM NIR and Optical refined analysis
Date
2005-05-16T22:12:22Z (21 years ago)
Edited On
2026-04-24T17:51:13Z (6 months ago)
From
Paolo D'Avanzo at INAF-OAB <davanzo@merate.mi.astro.it>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
S. Piranomonte, P. D'Avanzo, L.A. Antonelli, S. Covino, D. Malesani,
F.M. Zerbi, G. Chincarini, M. Rodono', G. Tosti, P. Conconi, G.
Cutispoto, E. Molinari, L. Nicastro, E. Palazzi, V. Testa, F. Vitali, E.
Meurs, P. Goldoni, on behalf of the REM/ROSS Team report:
Following the detection of a candidate optical counterpart for XRF
050509c (HETE trigger #3751; GCN 3402), by Gorosabel et al. (GCN 3425)
we re-analyzed our optical and NIR REM data (D'Avanzo et al GCN 3400).
At 2.5 hours after the burst no object is found at the position of the
candidate down to a limiting magnitude of R=19 and H=15.5 (3-sigma
level). We note that our R limit is consistent with a power-law decay
index of -1.2 (Gorosabel et al. GCN 3425).
This message may be cited.
GCN Circular 3425
Subject
XRF 050509c optical afterglow
Date
2005-05-16T10:55:28Z (21 years ago)
Edited On
2026-04-24T17:51:11Z (6 months ago)
From
Jens Hjorth at U.Copenhagen <jens@astro.ku.dk>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
J. Gorosabel (IAA-CSIC), B. L. Jensen (NBI), G. Galaz (Pont. Uni. de Chile),
R. Salinas (Uni. de Concepcion), J. Hjorth, J. P. U. Fynbo, H. Pedersen,
D. Watson, P. Jakobsson, J. M. Castro Cerón (NBI), report:
"We have carried out R-band observations of XRF 050509c (HETE trigger #3751;
GCN 3402) error box with the 1.54m Danish telescope (+DFOSC) on La Silla,
as follows:
======================================
Date UT t-to Texp Seeing
May 2005 (hr) (s) (")
--------------------------------------
10.1545-10.1703 5.1 2x600 1.2
14.0490-14.0829 98.8 4x600 1.3
======================================
Both observations are centred in the SXC error box covering ~80% of it.
Comparison of the two epoch images reveals, well centred in the SXC error
box, a fading point-like object with coordinates:
RA(J2000) = 12:52:53.94
Dec(J2000) = -44:50:04.1 (internal astrometric error of 1")
which we propose as the XRF 050509c optical afterglow.
Assuming R = 17.9 for the USNO star placed at (12:52:52.34, -44:49:23.1)
we estimate a decay from R~20.1 to R~24.0 between the two epochs. This
would imply a power-law decay index of -1.2 typical of GRB afterglows.
Finding charts can be found at:
http://www.dsri.dk/~jgu/grb050509c/FCs/grb050509c.1.54dk.epoch1.gif
http://www.dsri.dk/~jgu/grb050509c/FCs/grb050509c.1.54dk.epoch2.gif
Further observations are planned."