GRB 090516
GCN Circular 9415
Subject
GRB 090516: Fermi GBM observation
Date
2009-05-21T08:51:16Z (16 years ago)
From
Sheila McBreen at MPE <smcbreen@mpe.mpg.de>
Sheila McBreen (UCD/MPE)
reports on behalf of the Fermi GBM Team:
"At 08:27:58.35 UT on 16 May 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090516 (trigger 264155280 / 090516353).
which was also detected by the Swift-BAT
(Rowlinson et al. 2009, GCN 9374).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 20 degrees.
The GBM light curve consists of about five overlapping
pulses from T0-50 s to T+120 s. There is continued weak emission
until about T0+300 s (8-1000 keV).
Due to a large change in the spacecraft pointing during this long
burst, a time averaged spectrum could not be fit. Instead three
spectral intervals from -50 to 20 sec, 20 to 60 sec
and 60 to 120 seconds were selected.
The first interval was well fit by a power law function with
an exponential high energy cutoff. The power law index
is -1.51 ( +/-0.11 ) and the cutoff energy, parameterized as
Epeak, is 185.6 (+98.4/-42.5) keV.
The second and third intervals are adequately fit by a Band function.
The parameters for interval two are alpha = -1.03 (+0.26/-0.31) ,
Epeak = 51.4 (+20.1, -11.4), beta= -2.1 ( +0.1/-0.2)
and for the third interval, alpha = 0.30 (+1.30/ - 0.78),
Epeak = 27.87 +/- 5.0), beta = -2.64 +/-0.4.
The sum of the event fluence (8-1000 keV) in these time intervals is
(2.3 +/- 0.5)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+28.6 s in the 8-1000 keV band
is 5.3 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 9396
Subject
GRB 090516: Observations from Stardome Observatory
Date
2009-05-19T06:10:37Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
G. W. Christie (Stardome, New Zealand), A. de Ugarte Postigo
(ESO, Chile) and T. Natusch (Stardome, New Zealand) on
behalf of a larger collaboration report:
We observed the field of GRB 090516 (Rowlinson et al. GCN
9374) with the Stardome 0.4m telescope located in Auckland
(New Zealand) starting at 09:25UT. We used a SG530 filter
that transmits wavelengths above 5300 Angstroms and a SBIG
ST-L-6303E CCD (KAF-6303E detector). A 9x300s combined
exposure with mean epoch 16.4080 May (80 minutes after the
burst) shows an object at the position of the afterglow
(Guidorzi et al. GCN 9375) measured at R = 20.8 +/- 0.2 as
compared to USNO-B1.0 stars. We note that with the GRB at
a redshift of 4.1 (de Ugarte Postigo et al. GCN 9383),
Ly-alpha falls within the R-band, so that comparison of
clear and very broad band filters such as ours with R-band
has to be handled with care.
GCN Circular 9391
Subject
GRB 090516, RIMOTS optical upper limits
Date
2009-05-18T13:29:42Z (16 years ago)
From
Norisuke Ohmori at Miyazaki U <ohmori@astro.miyazaki-u.ac.jp>
N. Ohmori, E. Sonoda, K. Kono, H. hayasi,
A. Daikyuji, Y. Nisioka, K. Noda, M. Yamauchi
(University of Miyazaki)
We have observed the field covering the error circle of
GRB090516 (Swift trigger 352190, GCN 9374, Rowlinson et al.)
with the unfiltered CCD camera on the 30-cm telescope
at University of Miyazaki.
The observation was started 11:16:08 UT (1.8 hr after the Swift trigger),
under cloudy condition.
First image was obtained at 11:17:11 UT (1.8 hr after the Swift trigger).
We have compared our data of 30 sec exposures with the USNO-A2.0 catalog.
There is no new source at the reported position.
(GCN 9374, B. A. Rowlinson et al. GCN 9375, C. Guidorzi et al.
GCN 9376, A. P. Beardmore et al. GCN 9379, J. Gorosabel et al.
GCN 9381, A. de Ugarte Postigo et al.)
the upper limits are as follows:
---------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
---------------------------------------------------------------
11:16:08 11:17:11 1 15.6
11:16:08 12:04:00 21 17.7
---------------------------------------------------------------
GCN Circular 9384
Subject
GRB 090516: Swift-BAT refined analysis
Date
2009-05-17T16:59:56Z (16 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), B. A. Rowlinson (U Leicester),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 090516 (trigger #352190)
(Rowlings, et al., GCN Circ. 9374). The BAT ground-calculated position is
RA, Dec = 138.246, -11.848 deg, which is
RA(J2000) = 09h 12m 59.1s
Dec(J2000) = -11d 50' 51.4"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 9%.
The mask-weighted light curve shows several overlapping peaks starting
at ~T-20 sec witht he last peak at ~T+180 sec, and then decaying
to background at ~T+330 sec. The burst went out of the BAT FOV at T+700 sec
when Swift did a pre-programmed slew.
T90 (15-350 keV) is 210 +- 65 sec (estimated error including systematics).
The time-averaged spectrum from T-15.5 to T+288.5 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.84 +- 0.11. The fluence in the 15-150 keV band is 9.0 +- 0.6 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+7.98 sec in the 15-150 keV band
is 1.6 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/352190/BA/
[GCN OPS NOTE(17may09): Per author's request, the TBDs in the first sentence
in the third paragraph were replaced with the actual times.]
GCN Circular 9383
Subject
GRB 090516: VLT spectrum (correction & update)
Date
2009-05-17T08:38:02Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (ESO), J. Gorosabel (IAA/CSIC), D. Malesani,
J.P.U. Fynbo (DARK/NBI), A. J. Levan (Univ. Warwick), report on
behalf of a larger collaboration:
We have reanalysed the spectrum of the afterglow of GRB 090516
(Rowlinson et al., GCN 9374; Guidorzi et al., GCN 9375) obtained
with the ESO VLT (de Ugarte Postigo et al. GCN 9381). Due to an
error in the preliminary reduction, the wavelength calibration had an
offset that has been now corrected.
In our new analysis we detect a strong Ly-alpha absorption
together with absorption lines of NV, SII, SiII, NiII, CI, SiIV, CIV,
FeII, AlII, AlIII as well as SiII* at a redshift of 4.109+/-0.002,
which we identify as the redshift of the afterglow. This is in
agreement with the photometric redshift obtained with GROND (Rossi
et al. GCN 9382).
The spectrum also shows an intervening system at z=2.697+/-0.002,
characterised by the presence of several FeII absorption lines.
[GCN OPS NOTE(17may09): Per author's request, the Subject line
was changed from "091516" to "090516". And in the first sentence
from "090416" to "090516".]
GCN Circular 9382
Subject
GRB 090516: GROND OBSERVATIONS
Date
2009-05-17T05:00:40Z (16 years ago)
From
Andrea Rossi at TLS Tautenburg <rossi@tls-tautenburg.de>
A. Rossi (Tautenburg), P. Afonso and J.Greiner (both MPE Garching)
report on behalf of the GROND team:
We observed the field of GRB 090516 (Swift trigger 352190, B. Rowlinson et
al.,GCN #9374) simultaneously in g'r'i'z'JHK with GROND mounted at the 2.2m
ESO/MPI telescope at La Silla Observatory (Chile). Observations started on
16 May 2009 at 23:04 UT, 14.6 h after the burst.
We detect the afterglow at a position consistent with the enhanced
XRT error circle (A. Beardmore et al., GCN #9376) and NOT (J. Gorosabel et al.,
GCN #9379) and Faulkes Telescope detections (C. Guidorzi et al., GCN #9375).
With an exposure time of 20min in JHK and 25min in griz, preliminary photometry
yields the following AB magnitudes:
g =23.60 +-0.1
r =21.44 +-0.1
i =20.38 +-0.1
z =19.95 +-0.1
J =19.6 +-0.1
H =19.2 +-0.1
K =19.1 +-0.2
The quoted error is statistical only. There is an additional systematic
error in the absolute calibration using the GROND zero points and 2MASS
field stars which is expected to be in the 0.2 mag range. Quoted magnitudes
are not corrected for the galactic foreground extinction corresponding to a
reddening of E_(B-V)=0.05.
Preliminary results fitting the SED with Hyperz give for no reddening a z ~ 4.5
and for best fitting solution a photometric redshift of 4.1 +- 0.3, with
SMC reddening of A_v = 0.4. This SMC photometric redshift is compatible
with VLT's spectroscpic redshift of z = 3.9 (A. de Ugarte Postigo et al.
GCN #9381).
GCN Circular 9381
Subject
GRB 090516: VLT redshift
Date
2009-05-17T02:47:56Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (ESO), J. Gorosabel (IAA/CSIC), D. Malesani,
J.P.U. Fynbo (DARK/NBI), A. J. Levan (Univ. Warwick), report on
behalf of a larger collaboration:
We observed the optical afterglow of GRB 090516 (Rowlinson et al.,
GCN 9374; Guidorzi et al., GCN 9375) with the ESO VLT equipped
with FORS2. Observations started on 2009 May 16.989 UT (15.1 hr
after the GRB). In the acquisition image, the afterglow is well detected
with R ~ 21.2, consistent with the NOT measurement (Gorosabel et al.,
GCN 9379).
Two spectra lasting 30 min each were acquired with the grism 300V,
covering the wavelength range 3500-9200 AA. In a preliminary analysis
we detect the Lyman limit, a strong Ly-alpha absorption as well as
a number of strong absorption lines (SII, OI, CII, SiIV, CIV, AlII etc.)
at a redshift of z=3.9.
We acknowledge excellent support from the observing staff in Paranal,
in particular Alain Smette, Leo Rivas and Gianni Marconi.
GCN Circular 9380
Subject
GRB 090516 - Zadko Telescope observations
Date
2009-05-17T02:14:33Z (16 years ago)
From
David Coward at U of Western Aus. <coward@physics.uwa.edu.au>
SUBJECT: GRB 090516 - Zadko Telescope observations
FROM: D.M Coward at UWA
T.P. Vaalsta, Liang Yan, and J. Zadko report on
behalf of the Zadko Telescope Team.
T.P. Vaalsta, Liang Yan, J. Zadko, H. Miao,
J. Moore, K. Frost, D. Coward, A. Imerito, D. Blair,
R. Burman, P. Luckas, S. Gordon, A. Fletcher,
A. Ahmet, (University of Western Australia)
M. Todd, M. Zadnik (Curtin University)
M. Boer, A. Klotz (TAROT)
The 1.0m F/4 Zadko telescope started imaging
the field of GRB 090516 (trigger=352190, D. Palmer
et al., GCN 9374) 275 minutes after the Swift
trigger. A fading source was found within the
XRT error circle (GCN 9376). The field was
observed for 131 minutes.
Preliminary photometry of unfiltered images
taken with an iKon DW436BV camera show the
following initial magnitudes of the optical
afterglow:
tmid(m) Exp. Time Magnitude
-------------------------------------
275 5s 18.9 +/- 0.5
285 20s 19.5 +/- 0.3
296 200s 20.26 +/- 0.14
Dr David Coward
Senior Research Fellow
School of Physics
University of Western Australia
Crawley WA 6009
Tel: +61 8 6488 4563
Mobile 0423981240
Fax: +61 8 6488 1170
GCN Circular 9379
Subject
GRB 090516: NOT optical observations
Date
2009-05-16T22:47:41Z (16 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Gorosabel (IAA-CSIC), de Ugarte Postigo (ESO, Santiago), D. Montes
(UCM, Madrid), A. Klutsch (UCM, Madrid), A.J. Castro-Tirado (IAA-CSIC),
report on behalf of a larger collaboration:
We observed the optical afterglow of GRB 090516 (Guidorzi et al. GCN
9375) with the 2.5m NOT(+STANCAM) telescope. On May 16.889 UT (12.9
hours post GRB) the afterglow shows an R-band magnitude of R=21.3+/-0.1
against USNO-B1.0 field stars.
GCN Circular 9378
Subject
GRB 090516: Swift XRT refined analysis
Date
2009-05-16T20:04:01Z (16 years ago)
From
Antonia Rowlinson at U.of Leicester <bar7@star.le.ac.uk>
B. A. Rowlinson and P. Evans (U Leicester) report on behalf of the
Swift-XRT team:
We have analysed 3.0 ks of XRT data for GRB 090516 (Rowlinson et al. GCN
Circ. 9374), from 170 s to 6.4 ks after the BAT trigger. The data
comprise 327 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The enhanced XRT position for this burst was given
by Beardmore et al. (GCN. Circ 9376).
The light curve can be modelled with a power-law decay with two flares
superimposed on it. The initial decay index is alpha=3.27 (+0.11,
-0.10). At T+601 (+138, -52) s the decay flattens to an alpha of 0.93
(+0.11, -0.10).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.09 (+/-0.04). The
best-fitting absorption column is 1.57 (+0.10, -0.09) x 10^21 cm^-2, in
excess of the Galactic value of 4.5 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.09 (+0.13, -0.12)
and a best-fitting absorption column of 9.6 (+2.6, -2.5) x 10^20 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.6 x 10^-11 (4.8 x 10^-11) erg cm^-2
count^-1.
If the light curve continues to decay with a power-law decay index of
0.93, the count rate at T+24 hours will be 0.03 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-12 (1.4 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00352190.
This circular is an official product of the Swift-XRT team.
GCN Circular 9377
Subject
GRB 090516: Swift/UVOT Observations
Date
2009-05-16T18:45:43Z (16 years ago)
From
Mike Siegel at PSU/Swift MOC <siegel@astro.psu.edu>
M. H. Siegel (PSU) and B. A. Rowlinson (Leicester) report on behalf
of the Swift/UVOT team.
The Swift/UVOT began observing the field of GRB 090516 171s after
the BAT trigger (Beardmore et al., GCN Circ. 9374). Data summed
from the first and second orbits does not reveal a source at the
refined position of the X-ray afterglow (Beardmore et al., GCN Circ.
9376).
The 3-sigma upper limits for the finding chart (fc) and
summed exposures are reported below:
FILTER T_start(s) T_stop Exposure Mag/3UL
=============================================================
white fc 171 321 147 > 20.85
white 3843 5478 393 > 21.06
v 4254 5890 393 > 19.63
b 585 601 15 > 18.74
b 5073 5273 196 > 20.32
u 329 579 245 > 20.12
u 4868 6384 274 > 20.20
uvw1 4664 6301 393 > 20.36
uvm2 4458 6096 393 > 20.18
uvw2 4049 5685 393 > 20.41
=================================================================
The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.05 (Schlegel et al.,
1998, ApJS, 500, 525). The photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383, 627).
GCN Circular 9376
Subject
GRB 090516: Enhanced Swift-XRT position
Date
2009-05-16T14:06:48Z (16 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 2534 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 090516, 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 = 138.26050, -11.85442 which is equivalent
to:
RA (J2000): 09h 13m 2.52s
Dec (J2000): -11d 51' 15.9"
with an uncertainty of 1.5 arcsec (radius, 90% confidence).
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, arXiv:0812.3662).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 9375
Subject
GRB 090516: Faulkes Telescope South optical afterglow
Date
2009-05-16T10:08:59Z (16 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi (U. Ferrara), I. A. Steele, A. Melandri, D. Bersier,
C.J. Mottram, C.G. Mundell, R.J. Smith (Liverpool JMU),
A. Gomboc (U. Ljubljana), P. O'Brien, N. Bannister,
N. Tanvir (U. Leicester) on behalf of a large collaboration report:
The 2-m Faulkes Telescope South reacted to the Swift burst
GRB 090516 (trigger=352190, Rowlinson et al. GCN 9374).
Observations started about 16.9 min after the trigger time with filters
BRi. Within the XRT error circle we found a fading source at the following
position (J2000):
RA: 09:13:02.62
Dec: -11:51:15.4
with an initial approximate magnitude of R~19 at 17 minutes post trigger.
GCN Circular 9374
Subject
GRB 090516: Swift detection of a burst
Date
2009-05-16T08:49:10Z (16 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
B. A. Rowlinson (U Leicester), A. P. Beardmore (U Leicester),
P. A. Evans (U Leicester), C. Guidorzi (U Ferrara),
J. A. Kennea (PSU), P. T. O'Brien (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
P. Romano (INAF-IASFPA) and T. Sakamoto (NASA/UMBC) report on behalf
of the Swift Team:
At 08:27:50 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 090516 (trigger=352190). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 138.271, -11.858 which is
RA(J2000) = 09h 13m 05s
Dec(J2000) = -11d 51' 27"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multiple-peaked
structure with a duration of at least 150 sec. The peak count rate
was ~1000 counts/sec (15-350 keV), at ~5 sec after the trigger, with
additional prominent peaks at T+35, T+90 and T+135.
The XRT began observing the field at 08:30:37.4 UT, 166.7 seconds after
the BAT trigger. Using promptly downlinked data we find a bright, fading,
uncatalogued X-ray source located at RA, Dec 138.26119, -11.85480 which
is equivalent to:
RA(J2000) = 09h 13m 2.69s
Dec(J2000) = -11d 51' 17.3"
with an uncertainty of 4.1 arcseconds (radius, 90% containment). This
location is 36 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
4.47e+20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 0.1 s image was 1.96e-08 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 176 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.05.
Burst Advocate for this burst is B. A. Rowlinson (bar7 AT star.le.ac.uk).
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.)