GRB 100816A
GCN Circular 11102
Subject
GRB 100816A: Swift detection of a possibly short burst with optical afterglow
Date
2010-08-16T01:17:12Z (15 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
S. R. Oates (UCL-MSSL), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), O. M. Littlejohns (U Leicester),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL),
C. J. Saxton (UCL-MSSL), M. Stamatikos (OSU/NASA/GSFC) and
R. L. C. Starling (U Leicester) report on behalf of the Swift Team:
At 00:37:51 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100816A (trigger=431764). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 351.740, +26.561 which is
RA(J2000) = 23h 26m 58s
Dec(J2000) = +26d 33' 38"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single symmetric
peak structure with a duration of about 2 sec. There is possible
further activity at around T+80s. The peak count rate
was ~13000 counts/sec (15-350 keV), at ~0.5 sec after the trigger.
The XRT began observing the field at 00:39:14.2 UT, 82.8 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 351.7381, +26.5785 which is equivalent to:
RA(J2000) = 23h 26m 57.15s
Dec(J2000) = +26d 34' 42.6"
with an uncertainty of 5.5 arcseconds (radius, 90% containment). This
location is 63 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
UVOT took a finding chart exposure of 150 seconds with the White
filter starting 91 seconds after the BAT trigger. The refined UVOT
position is
RA (J2000) 23:26:57.56
Dec (J2000) 26:34:42.9 with an estimated uncertainty of 0.5
arcsec (radius, 90% confidence). This position is 5.5 arc sec. from
the center of the XRT error circle. The estimated magnitude is 17.00
with a 1-sigma error of about 0.03. No correction has been made for
the expected extinction corresponding to E(B-V) of 0.09.
There were no real-time GCN Notices on this burst because the block2world
filter was still in place due to the earlier episode of the startracker
loss-of-lock problem. The MOC had just gotten the startracker back to lock
and BAT triggers restored when the trigger occurred. But the block2world
had not yet been removed. BAT_POSITION and XRT_POSITION notices were manually
generated and distributed.
Burst Advocate for this burst is S. R. Oates (sro AT mssl.ucl.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.)
GCN Circular 11103
Subject
GRB 100816A: ROTSE-III Optical Limits
Date
2010-08-16T01:42:21Z (15 years ago)
From
Shashi Bhushan Pandey at ROTSE <shaship@umich.edu>
S. B. Pandey (U Mich), report on behalf of the ROTSE collaboration:
ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia,
responded to GRB 100816A, possibly a short duration burst, (Swift trigger
431764; Oates, S. R., GCN 11102), producing images beginning 6.8 s after
the GCN notice time. An automated response took the first image at
01:00:05.7 UT, 1334.3 s after the burst, under fair conditions. We took 10
5-sec, 10 20-sec and 10 60-sec exposures. These unfiltered images are
calibrated relative to USNO A2.0 (R). Imaging is on going.
Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma Swift/BAT error circle or the XRT error circle. Individual images
have limiting magnitudes ranging from 16.2-17.9; we set the following
specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
01:00:05.8 01:00:10.8 5 16.6 1334.4 N
01:01:37.27 01:05:58.67 180 18.5 1534.4 Y
GCN Circular 11104
Subject
GRB100816A: TNG optical afterglow confirmation.
Date
2010-08-16T06:28:22Z (15 years ago)
From
Angelo Antonelli at Obs. Astro. di Roma <angelo.antonelli@oa-roma.inaf.it>
L. A. Antonelli (INAF-OAR), A. Fiorenzano (INAF-TNG), G. Tessicini
(INAF-TNG), A. Stamerra (UniPisa) on behalf of the CIBO collaboration
report:
We observed the field of the short hard GRB100816A (Swift trigger
431764; Oates et al., GCN 11102) with the Italian 3.6m TNG telescope
(La Palma, Canary Islands) equipped with the DOLORES camera.
Observations started on Aug 16 at 03:22 UT (~2.8 hrs after the burst)
under very poor weather conditions (high cloudiness and high
humidity). We acquired a R band image of the GRB field for a total
exposure time of 180s. We clearly detect a source consistent with the
one reported by (Oates et al., GCN 11102). This souce, located at RA
(J2000)=23:26:57.58; Dec(J2000)=+26:34:42.7 (+/-0.5''), showed a
magnitude R~20.5 (calibrated against USNO B1.0) at the epoch of the
observation. Due to its fading behavior with respect to the UVOT
observation, we confirm that this source is the optical afterglow of
GRB100816A.
This message can be cited."
GCN Circular 11105
Subject
GRB 100816A: MASTER Optical Limits
Date
2010-08-16T12:00:01Z (15 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina,
D.Kuvshinov, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov,
M. Kornilov
Sternberg Astronomical Institute, Moscow State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk
V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
Ural State University, Kourovka
K.Ivanov, S.Yazev, N.M.Budnev, E.Konstantinov, V.Lenok, O.Gres, O.Chuvalaev
Irkutsk State University
MASTER robotic telescopes (MASTER-Net: http://observ.pereplet.ru, 6
Very Wide Field cameras and 2 Wide Field Telescopes ) located near
Kislovodsk was pointed to the GRB 100816A (Oates et al., GCN Circ N
11102) 21 sec after Notice time and 1350 s after trigger time (before
sunrise).
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? Filter
--------------------------------------------------------------------------
01:00:21.0 01:03:21.0 180 17.2 1350.0 N Polarization
There are 6 very wide field cameras located at Kislovodsk with total FOV
= 3 000 square degrees. Unfortunately, GRB was 4 degrees outside FOV.
The message may be cited.
mailto: lipunov@sai.msu.ru
GCN Circular 11106
Subject
GRB 100816A: TAROT Calern observatory optical detection
Date
2010-08-16T14:38:10Z (15 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz A. (CESR-OMP), Gendre B. (IASF),
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:
We imaged the field of GRB 100816A detected by SWIFT
(trigger 431764) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.
The observations started 1339s after the GRB trigger
The elevation of the field increased from
72 degrees above horizon and weather conditions
were good.
We co-added a series of 30s unfiltered exposures.
We detect the OT mentioned by Oates et al. 2010 (GCNC 11102)
very close to the limiting magnitude of the image :
start exp. = 1339s
end exp. = 1601s
R ~ 19.2
Magnitudes were estimated with the nearby
star NOMAD-1 1165-0624306 and are not corrected
for galactic dust extinction.
GCN Circular 11108
Subject
GRB 100816A: CQUEAN riz-band Detection, Host Galaxy?
Date
2010-08-16T15:59:01Z (15 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
Myungshin Im, Won-Kee Park (CEOU/Seoul National Univ),
Soojong Pak, Hyeonju Jeong, Eunbin Kim, and Jinyoung Kim
(Kyunghee University)
We observed GRB 100816A (Palmer et al. GCN 11102) with the SDSS
r,i,z-filters during the commissioning run of CQUEAN (the Camera for
QUasars in the Early uNiverse)on the 2.1m telescope at the McDonald
observatory. The observation started at 2010 August 16, 08:33:46 UT,
about 8 hours after the BAT trigger. A series of 300 secs exposures
were taken.
We identify an object within the error circles reported by UVOT
(Palmer et al. GCN 11102), and by Antonelli et al. (GCN 11104) which
faded significantly, confirming its GRB afterglow nature.
We also notice another extended object, about 1.3" to the South
of the afterglow at RA=23:26:57.53 and Dec= +26:34:41.6 with ~0.4"
error in position.
The close proximity of the object to the afterglow suggests that
this second object is possibly a host galaxy of GRB 100816A,
although a chance projection cannot be ruled out.
GRB host GRB+host mid-point (UT)
r (unresolved) 21.4 08:39:36
i 21.31 20.58 - 08:45:08
The magnitudes are in AB, and the error of the photometry is
about 0.1 mag. The photometry calibration is done with a standard
star observation.
The finding charts are available at
http://astro.snu.ac.kr/~mim/grb/grb100816A/grb100816A_small.jpg
http://astro.snu.ac.kr/~mim/grb/grb100816A/grb100816A_large.jpg
N is up, and E is left. Further analysis of the data is
ongoing.
We thank the staffs of the McDonald observatory, David Doss,
Peter S. Odoms, and John Kuehne for their assistance of
the CQUEAN commissioning run.
GCN Circular 11109
Subject
GRB 100816A: Gemini-N imaging
Date
2010-08-16T16:03:01Z (15 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
N. R. Tanvir, K. Wiersema (U. Leicester), A. J. Levan (U. Warwick),
D. Perley (UC Berkeley) report on behalf of a larger collaboration:
We imaged the field of possibly short GRB 100816A (Oates et al.
GCN 11102) with Gemini-N/GMOS, beginning about 11:33 (UT),
approximately 11 hours post-burst.
The afterglow detected by UVOT and confirmed to be fading
by the TNG (Antonelli et al. GCN 11104) is clearly detected at
a magnitude R~22.4, calibrated against USNO-B1 stars in the
field. We also detect a relatively bright galaxy centred about 1.2 arcsec
south of the afterglow, which may well be the host of the burst.
The magnitude of the galaxy is comparable to that of the
afterglow at this time.
Analysis of spectroscopic observations is ongoing.
We thank the Gemini observers, particularly Alexander
Fritz, for their assistance in obtaining these observations.
GCN Circular 11110
Subject
GRB 100816A: Enhanced Swift-XRT position
Date
2010-08-16T17:30:46Z (15 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 406 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 100816A, 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 = 351.74010, +26.57887 which is equivalent
to:
RA (J2000): 23h 26m 57.62s
Dec (J2000): +26d 34' 43.9"
with an uncertainty of 1.6 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, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 11111
Subject
GRB 100816A, Swift-BAT refined analysis
Date
2010-08-16T17:33:20Z (15 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <james.r.cummings@nasa.gov>
C. B. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
S. R. Oates (UCL-MSSL), D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-119 to T+263 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 100816A (trigger #431764)
(Oates, et al., GCN Circ. 11102). The BAT ground-calculated position is
RA, Dec = 351.738, 26.568 deg which is
RA(J2000) = 23h 26m 57.1s
Dec(J2000) = +26d 34' 04.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 33%.
The mask-weighted light curve shows a single symmetric peak. There is
low-level ongoing emission out to about T+100 sec. T90 (15-350 keV) is
2.9 +- 0.6 sec (estimated error including systematics).
The time-averaged spectrum from T-0.7 to T+4.5 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 0.73 +- 0.24,
and Epeak of 170.7 +- 79.7 keV (chi squared 50.79 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 2.0 +- 0.1 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+0.10 sec in the 15-150 keV band is
10.9 +- 0.4 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.16 +- 0.06 (chi squared 61.72 for 57 d.o.f.). 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/431764/BA/
GCN Circular 11112
Subject
GRB 100816A: 1.23m CAHA optical observations
Date
2010-08-16T18:39:32Z (15 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
V. Terron, M. Fernandez, A.J. Castro-Tirado, J. Gorosabel (IAA-CSIC),
report on behalf of a larger collaboration:
We carried out BVRI-band observations of the Swift GRB 100816A (Oates
et al., GCNC 11102) with the 1.23m Calar Alto telescope. The optical
afterglow (Oates et al., GCNC 11102; Antonelli et al., GCNC 11104) is
well detected in BVRI with a preliminary magnitude of I~19.9 on Aug
16.0492 UT (~33 min post burst), calibrated using USNO-B1.0 field stars.
GCN Circular 11113
Subject
GRB 100816A: Swift-BAT spectral lag results
Date
2010-08-16T18:58:58Z (15 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
J. Norris (U. Denver), T. N. Ukwatta (GWU/GSFC), S. D. Barthelmy (GSFC),
N. Gehrels (GSFC), M. Stamatikos (OSU/NASA/GSFC), and T. Sakamoto (GSFC/UMBC)
for the Swift-BAT team:
For GRB 100816A (Oates et al GCN 11102), the BAT team has analyzed the
spectral lags for the data from ~T-1 sec to ~T+3 sec using unmask-weighted
light curves. The spectral lags were measured between standard BAT energy
bands: channel 1 (15-25 keV), 2 (25-50 keV), 3 (50-100 keV) and 4 (100-350 keV)
are given below.
Lag Ch4-2 10 +/- 25 ms
Lag Ch3-1 20 +/- 20 ms
We conclude from this analysis that the burst is consistent with being
a short hard burst, but the error bars are too large to be definitive.
GCN Circular 11114
Subject
GRB100816A Swift-XRT refined analysis
Date
2010-08-16T20:00:21Z (15 years ago)
From
Owen Littlejohns at U of Leicester <oml2@star.le.ac.uk>
O. M. Littlejohns (U. Leicester) and S. R. Oates (UCL-MSSL) report on
behalf of the
Swift-XRT team:
��
We have analysed 4.4 ks of XRT data for GRB 100816A (Oates et al. GCN
Circ. 11102), from 89 s to 12.2 ks after the BAT trigger. The data
comprise 144 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The enhanced XRT position for this burst was given
by Evans et al. (GCN. Circ 11110).
��
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.29 (+0.05, -0.04), with some flaring activity during
the first snapshot.
��
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.16 (+0.22, -0.21). The
best-fitting absorption column is 1.4 (+0.5, -0.4) 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 2.10 (+0.19, -0.16)
and a best-fitting absorption column of 1.5 (+0.5, -0.4) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.8 x 10^-11 (5.5 x 10^-11) erg cm^-2
count^-1.
��
If the light curve continues to decay with a power-law decay index of
1.29, the count rate at T+24 hours will be 1.6 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.9 x
10^-14 (8.6 x 10^-14) erg cm^-2 s^-1.
��
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00431764.
This circular is an official product of the Swift-XRT team.
GCN Circular 11115
Subject
GRB 100816A: Swift UVOT Observations
Date
2010-08-16T21:34:49Z (15 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates (MSSL-UCL) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began observing the field of GRB 100816A 91s
after the BAT trigger (Oates et al., GCN Circ. 11102). We detect the
optical afterglow significantly in the white and u filters and
marginally in the v, b and uvw1 filters. The best UVOT position was
reported
in Oates et al. (GCN Circ. 11102), and is consistent with the
XRT enhanced position (Evans et al., GCN Circ 11110) and with the
optical
afterglow position reported by TNG (Antonelli et al., GCN Circ 11104).
Preliminary magnitudes and the 3 sigma upper limits are reported below
for
individual white and u images and summed images for the v, b, uvw1,
uvm2 and uvw2 filters.
Filter T_start(s) T_stop(s) Exposure Mag/3SigUL
###########################################################
white (FC) 91 241 147 17.01 +/- 0.05
white 586 606 19 18.90 +/- 0.19
v 3991 5626 393 21.56 +/- 0.94
b 4811 6393 341 21.07 +/- 0.35
u (FC) 305 555 246 18.02 +/- 0.08
u 4606 4806 197 20.39 +/- 0.35
uvw1 4401 6036 393 20.98 +/- 0.44
uvm2 4196 34516 1279 > 21.42
uvw2 3787 28671 2475 > 22.19
###########################################################
The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.09 mag (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 11116
Subject
GRB 100816A: Gemini-N spectroscopy
Date
2010-08-16T22:32:01Z (15 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
N. R. Tanvir, K. Wiersema (U. Leicester), J. P. U. Fynbo (DARK)
A. J. Levan (U. Warwick) & D. Perley (UC Berkeley) report on
behalf of a larger collaboration:
We obtained medium resolution, long-slit spectroscopy of GRB 100816A
(Oates et al. GCN 11102) with Gemini-N/GMOS following the imaging
reported in Tanvir et al. (GCN 11109).�� The afterglow was centred in the
slit, and the nearby candidate host galaxy (see also Im et al. GCN 11108)
was also partially in the slit.�� The spectrum covers a wavelength range
from about 4000A to 6700A.
Our analysis of the galaxy trace provides a tentative detection of the OIII
(5007A/4959A) doublet and Hbeta (4863A) at a redshift of z~0.245, although
we caution that all these features are low S/N.�� No other lines are clearly seen
even though OII 3727A would be within the spectral range (but we note the
galaxy continuum is not apparent below about 4700A, in part due to declining
detector quantum efficiency in the blue).�� Neither have we identified so far
any significant features in the afterglow spectrum.
This is a similar redshift to a number of Swift short-duration burst hosts,
but further observations are encouraged to confirm the result.
We thank the Gemini observers, particularly Alexander
Fritz, for their assistance in obtaining these observations.
GCN Circular 11117
Subject
GRB 100816A : Lulin r'-band observation
Date
2010-08-17T08:02:50Z (15 years ago)
From
Yuji Urata at Nat. Central U. <urata@astro.ncu.edu.tw>
Y. Urata (NCU) and K.Y Huang (ASIAA)
on behalf of EAFON report;
"We started to observe the GRB 100816A (Palmer et al. GCN 11102) using
Lulin One-meter Telescope (LOT) with r'-band filter.
The observation started at 2010 August 16 18:09 about 17.5 hr after
the burst. The brightness of afterglow including the possible host
galaxy reported by Im et al. (# 11108) and Tanvir et al (# 11109) is
R=21.6+/-0.1 in Vega. The photometric calibration is performed against
USNO-B1 stars in the field."
GCN Circular 11120
Subject
GRB 100816A: NOT optical observations
Date
2010-08-17T09:24:04Z (15 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
D. Malesani (DARK/NBI), D. Xu (Weizmann Inst.), J.P.U. Fynbo (DARK/NBI),
P. Jakobsson (Univ. Iceland), L. Buchhave, T. Hansen (NBI), report on behalf of
a larger collaboration:
We observed the field of GRB 100816A (Oates et al., GCN 11102) with the
NOT equipped with ALFOSC. Observations were carried out in the R band.
The mid point of the observation is August 17.04 UT (24.3 hr after the GRB).
We clearly detect both the optical afterglow (Oates et al., GCN 11102)
and the putative host galaxy (Im et al., GCN 11108; Tanvir et al., GCN
11109). We find magnitudes of R = 23.0 +- 0.1 and R = 21.65 +- 0.05 for
the two objects, respectively, assuming R=17.06 for the nearby USNO star
1165-0595190. We caution that accurate photometry will have to await for
late-time templates to isolate the contribution of both objects.
[GCN OPS NOTE(17aug10): Per author's request, TH was added to the author list.]
GCN Circular 11123
Subject
GRB 100816A: VLT and Gemini-N revised redshift
Date
2010-08-17T12:56:20Z (15 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
N. R. Tanvir (U. Leicester), S. Vergani (GEPI/Obs. Paris and APC/Univ. Paris 7),
J. Hjorth, J. P. U. Fynbo, B. Milvang-Jensen, D. Malesani (DARK),
K. Wiersema (U. Leicester),�� P. Vreeswijk (Reykjavik), A. J. Levan (U. Warwick)
P. Goldoni (APC/Univ. Paris 7 and SAp/CEA), S. Covino (INAF/Brera), & L. A. Antonelli (INAF/Roma)
report on behalf of a larger collaboration:
We observed the location of possible short-hard GRB 100816A
(Oates et al. GCN 11102; Markwardt et al. GCN 11111; Norris et al. GCN 11116)
with VLT/X-Shooter on 2010 Aug 17 beginning 04:20 (UT).�� We clearly
detect the putative host galaxy of the burst, and identify lines of Halpha,
Hbeta,�� OII (3727), NII (6548/6583) and OIII (5007) in emission and CaII H&K
in absorption.�� In fact, the system splits (spectrally and spatially) into two
components at redshifts z=0.8034 and z=0.8049 (based on a provisional
wavelength calibration), possibly indicating an interacting system or reflecting
internal velocity components within a single galaxy.�� This redshift is inconsistent
with the tentative redshift for this galaxy suggested by Tanvir et al. (GCN 11116).
We have also re-analysed the Gemini-N GMOS afterglow spectroscopy initially
reported in GCN 11116.�� The trace shows faint absorption features
consistent with MgII (2797/2803A) doublet and FeII (2600A) at a redshift of
z=0.8035. The agreement of this redshift with that obtained for the galaxy from
the X-shooter data, strongly suggests that it is the host.�� We note that none of
the emission lines seen in the X-Shooter spectrum are within the spectral range
of the GMOS data.
We acknowledge the support of the VLT staff, in particular Giovanni Carraro.
[GCN OPS NOTE(19aug10): Per author's request, LAT was added to the author list.]
GCN Circular 11124
Subject
GRB 100816A: Fermi GBM observation
Date
2010-08-17T19:42:54Z (15 years ago)
From
Michael Burgess at UAH <james.burgess@uah.edu>
G. Fitzpatrick (UCD) reports on behalf of the Fermi GBM Team:
"At 00:37:50.94 UT on 16th August 2010, the Fermi Gamma-Ray Burst
Monitor
triggered and located GRB 100816A (trigger 303611872 / 100816026),
which was also detected by the SWIFT-BAT (Oates et al. 2010, GCN 11102)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 82 degrees.
The GBM light curve shows a single pulse with a duration (T90) of about
2 s (50-300 keV). The time-averaged spectrum from T0 to
T0+ 2.496 s is best fit by a Band function with Epeak = 136.70 +/-
4.73 keV, alpha = -0.31 +/- 0.05, and beta = -2.77 +/- 0.17
(Castor C-STAT 555.02 for 484 d.o.f.).
The event fluence (10-1000 keV) in this time interval is
(9.10 +/- 0.13) E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+ 0.38 s in the 10-1000 keV band
is 15.59 +/- 0.25 ph/s/cm^2.
A power law function with an exponential high energy cutoff fits
the spectrum equally well (Castor C-STAT 564.38 for 485 d.o.f.)
The cutoff energy, parameterized as Epeak, is 146.30 +/- 3.44 keV
and the power law index is -0.38 +/- 0.04.
The spectral and temporal analysis results presented above are
preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 11125
Subject
GRB 100816A: 10.4-m GTC redshift confirmation
Date
2010-08-17T21:32:54Z (15 years ago)
Edited On
2024-11-18T09:43:39Z (7 months ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
J. Gorosabel (IAA-CSIC, Granada), A.J. Castro-Tirado (IAA-CSIC), N. Tanvir (U. Leicester), A. de Ugarte Postigo (INAF-OAB), M. Jelinek (IAA-CSIC), P. Kubanek (IAA-CSIC & U. Valencia), R. Cunniffe (IAA-CSIC), M.D. Pérez-Ramírez (U. Jaen), J.M. Castro Cerón (ESAC), S. Guziy (IAA-CSIC), G. Gómez (GTC, La Palma), and J. Cepa (IAC, Tenerife), report on behalf of a larger collaboration:
"We acquired long-slit spectra of the optical afterglow of the possible short-duration GRB 100816A (Oates et al., GCNC 11102) with the 10.4-m Gran Telescopio Canarias (GTC) at the Observatorio del Roque de los Muchachos on the island of La Palma. Three spectra were taken under non optimal weather conditions with the OSIRIS instrument on Aug 16.1736 - 16.2060 UT (3.5-4.3 hr post-burst) with a total exposure time of 3x900s and covering an approximate spectral range of 4200-8700 A. A comparison of the GTC and the Gemini-N spectra (Tanvir et al., GCNC 11123) shows faint absorption features consistent with the MgII doublet at a preliminary redshift of z = 0.8049. At the present stage of the reduction we can not confirm the existence of emission lines."
We acknowledge the support of the GTC staff.
GCN Circular 11126
Subject
GRB100816A: MITSuME optical upper limits
Date
2010-08-18T06:09:10Z (15 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME collaboration:
We observed the field of GRB 100816A (Oates et al., GCN 11102)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2010-08-16 14:00:49 UT (~13.4 h after
the burst). We did not find any new point source within the
enhanced XRT error circle (Evans et al., GCNC 11110) in all
the three bands. We could not detect the previously reported
host galaxy (Im et al., GCN 11108; Tanvir et al., GCN 11109;
Malesani et al., GCN 11120).
Three sigma upper limits of the OT are listed below. We used
GSC 2.3 catalog for flux calibration.
T0+[day] MID-UT T-EXP[sec] g' Rc Ic
------------------------------------------------------
0.67447 16:49:05 6240.0 >21.0 >20.5 >19.9
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 11127
Subject
Konus-Wind observation of GRB 100816A
Date
2010-08-18T11:30:01Z (15 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
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 short GRB 100816A (Swift-BAT trigger=431764;
Oates et al., GCN 11102; Markwardt et al., GCN 11111)
triggered Konus-Wind at T0=02273.983s UT (00:37:53.983)
The burst light curve shows a single peak
with a total duration of ~2.8 s. There is also
a hint of a softer (<70 keV) short (~64ms)
weak spike at T0 + 4.7 s.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB100816_T02273/
As observed by Konus-Wind the burst
had a fluence of (3.3 +/- 0.4)x10-6 erg/cm2,
and a 64-ms peak flux measured from T0 + 0.896 s
of (2.3 +/- 0.4)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 best fit
in the 20 keV - 2 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.0(-0.3, +0.4),
and Ep = 148(-26, +41) keV (chi2 = 50.5/61 dof).
Fit of this spectrum by the GRB (Band) model
yields the same values of alpha and Ep, with
beta = -4.6 (<-2.5), chi2 = 50.5/60 dof.
Assuming z=0.8049 (Tanvir et al., GCN 11123;
Gorosabel et al., GCN 11125) and a standard
cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, Omega_Lambda = 0.73,
the isotropic energy release E_iso = (5.8 +/- 0.7)x10^51 erg,
the peak luminosity (L_iso)_max = (7.3 +/- 1.3)x10^51 erg/s.
All the quoted results are preliminary.
All the quoted errors are at the 90% confidence level.
GCN Circular 11128
Subject
GRB 100816A: Fermi GBM observation (correction to GCN 11124)
Date
2010-08-18T15:45:25Z (15 years ago)
From
Gerard Fitzpatrick at U.College Dublin/Fermi <gerard.fitzpatrick@gmail.com>
"G. Fitzpatrick (UCD) reports on behalf of the Fermi GBM Team:
Apologies, the event fluence (10-1000 keV) should be (3.84 +/- 0.13)
E-06 erg/cm^2. This is consistent with the value reported by
Konus-Wind (Golenetskii et al, GCN 11127).
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."