GRB 060116
GCN Circular 4602
Subject
GRB 060116 HST observations
Date
2006-01-26T13:02:46Z (20 years ago)
From
Nial Tanvir at IofA U.Cambridge <nrt@ast.cam.ac.uk>
N. R. Tanvir, A. J. Levan, R. S. Priddey (U. Hertfordshire)
A. S. Fruchter (STScI), J. Hjorth (DARK Cosmology Centre) report
on behalf of a larger collaboration:
We observed the field of GRB060116 (Campana et al . GCN 4539, Kocevski
et al. GCN 4528) with HST on Jan 23 and Jan 24. We clearly detect the
afterglow in NICMOS/F160W, but only obtain an upper limit in
ACS/F775W. A preliminary limit on the I-H vegamag colour is > 5.5.
If the suggested redshift of z=6.6 (Grazian et al. GCN 4545) is
correct then very little flux would be expected in the F775W
observation, consistent with our results.
However, we note that the location of this GRB is only about a degree
east of the Orion Nebula, and although the extinction in this area is
not very high, it is patchy and we caution that the Schlegel et
al. (1998 ApJ 500 525) extinction estimate for the burst position of
Av=1.20 (implying E(I-H)~0.5), may not be reliable. A map of
extinction in Orion based on optical star counts by Cambresy (1999 A&A
345 965) suggests a higher extinction Av between 2 and 2.5, but again
this is at best an average for the area. A similar star-count
analysis available at URL http://darkclouds.term.jp, also indicates
Av between 2.2 and 2.4 at the position of the burst.
The inferred X-ray column (Campana et al. GCN 4529) if interpretted as
purely local extinction gives Av around 4.3+/-1.3, apparently higher
than any of the above.
GCN Circular 4583
Subject
GRB 060116: Further analysis of VLT photometry and optical spectroscopy
Date
2006-01-24T21:45:37Z (20 years ago)
From
Daniele Malesani at SISSA-ISAS,Trieste,Italy <malesani@sissa.it>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
S. Piranomonte, V. D'Elia, P. D'Avanzo, D. Malesani, A. Grazian, D.
Fugazza, L.A. Antonelli, S. Campana, G. Chincarini, S. Covino, M. Della
Valle, A. Fernandez-Soto, F. Fiore, L. Stella, G. Tagliaferri, and V.
Testa, report on behalf of the MISTICI collaboration:
"We have performed a more detailed analysis of our optical/NIR
photometry (D'Avanzo et al., GCN 4532; Malesani et al., GCN 4541;
Grazian et al. GCN 4545) of the afterglow of GRB 060116 (Campana et al.,
GCN 4519, 4522; Kocevski et al., GCN 4528, 4540).
We compared the available photometry with a power law afterglow,
including rest frame dust extinction. The chi square versus z curve
presents two minima. The lowest chi square corresponds to the solution
with z~6.6 and little rest-frame extinction as reported in GCN 4545. The
other minimum corresponds to a solution with z=3.8-4.5 (1 sigma
confidence level) and E(B-V)~0.5.
On 2005 January 19, starting at 01:19 UT (about 2.7 days after the GRB),
we obtained low resolution spectra of the afterglow of GRB 060116
(Kocevski et al. GCNs 4528, 4540) using VLT+FORS2. The observation
consisted of 10 exposures of 1800 seconds each using the grism 300I with
a 1" slit under good seeing conditions. A very faint object, close to
the detection limit, is visible at the afterglow position in the
combined spectrum. Its spectrum may extend down to about 7000 Angstrom
blueward. This would be consistent with the lower redshift reported
above. However, the statistics is very poor and a robust conclusion can
not be drawn at this time. Further analysis is in progress.
We acknowledge the efficient support of the ESO staff at Paranal.
This message can be cited."
GCN Circular 4569
Subject
GRB 060116: Radio Detection
Date
2006-01-23T22:38:11Z (20 years ago)
From
Dale A. Frail at NRAO <dfrail@nrao.edu>
Dale A. Frail (NRAO) reports on behalf of a larger collaboration:
"We used the Very Large Array to observe the Swift burst GRB060116
(GCN 4519; GCN 4531) at a frequency of 8.46 GHz on 2006 January 21 and
23. At the position of the IR afterglow (GCN 4540; GCN 4545)
we detect a weak radio source.
Further observations are planned to monitor the source and to obtain
an accurate flux calibration.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 4568
Subject
GRB 060116: MARGE optical observations
Date
2006-01-23T22:20:50Z (20 years ago)
From
Heather Swan at U.of Michigan/ROTSE <hflewell@umich.edu>
H. Swan (U Mich), C. Akerlof (U Mich), E. Rykoff (U Mich), S. Yost (U
Mich) and I. Smith (Rice), report on behalf of the MARGE collaboration:
The AEOS Burst Camera (ABC) on the AEOS telescope, located at the Maui
Space Surveillance System on Haleakala, observed the fading counterpart
to GRB 060116 (Swift trigger 177533 (GCN 4519)). Images were taken
between 08:45:11 UT (7.7 minutes after it was detected by Swift) and
09:09:38 UT. These are unfiltered optical images. The diffraction
grating normally mounted on the ABC was temporarily removed to
accommodate observations of the final approach of the NASA Stardust
mission. After a comparison of our images with the USNO B 1.0 R2
catalog, we see a fading optical transient centered within 0.06" of the
OT reported by Kocevski (GCN 4528). A preliminary analysis gives an
R-equivalent magnitude of approximately 20.0+/-0.1 at 08:45:29 UT.
Further analysis is in progress.
GCN Circular 4545
Subject
GRB 060116: photometric redshift - the farthest GRB?
Date
2006-01-18T20:26:34Z (20 years ago)
From
Daniele Malesani at SISSA-ISAS,Trieste,Italy <malesani@sissa.it>
A. Grazian (INAF/OAR), A. Fernandez-Soto (Univ. Valencia), V. Testa
(INAF/OAR), D. Fugazza, P. D'Avanzo (INAF/OABr), L.A. Antonelli (INAF/OAR), D.
Malesani (SISSA/ISAS), G. Chincarini (Univ. Milano-Bicocca), G.
Tagliaferri, S. Campana, S. Covino (INAF/OABr), M. Della Valle
(INAF/OAA), F. Fiore, S. Piranomonte, and L. Stella (INAF/OAR), report
on behalf of the MISTICI collaboration:
The near-infrared counterpart (Kocevski, Bloom & McGrath, GCNs 4528,
4540) of GRB 060116 (Campana et al., GCN 4519; Barthelmy et al., GCN
4531) was observed again with the ESO VLT, adopting the FORS1 and ISAAC
instruments. Observations were clustered around 2005 Jan 18.1 UT.
The afterglow is clearly detected in the J, H and K filters, and is seen
to decline achromatically in J and K, comparing our new measurements
with those secured during the night of Jan 16 (D'Avanzo et al., GCN
4532; Malesani et al., GCN 4541). The power law decay index is alpha ~ 1.
The object is also detected in the z band, but is not seen in the I and
R filters.
By fitting the available photometry with a power law suppressed by
neutral Hydrogen absorption, we measure a photometric redshift z = 6.7
and z = 6.6 for the first and second night, respectively. Combining
together the two datasets, we get z = 6.60, the 1-sigma confidence
interval being 6.45 < z < 6.75. The observed NIR spectral index
(rest-frame UV) is quite steep, indicating
significant extinction in the rest frame.
GRB 060116 may thus be the farthest observed GRB, and rank among the
most distant objects detected to date in the Universe.
We would like to acknowledge the painstaking work of the ESO staff to
perform our service-mode observations. In particular, the ISAAC NIR
observations were carried out during technical time. We are particularly
grateful to Gianni Marconi, Jose Cortes, Lorena Faundez, Elena Mason,
and Dominique Naef.
This message can be cited.
[GCN OPS NOTE(18jan06): Per athor's request, D. Fugazza was added to the author list.]
GCN Circular 4541
Subject
GRB 060116: possible I-J dropout
Date
2006-01-18T10:21:14Z (20 years ago)
From
Daniele Malesani at SISSA-ISAS,Trieste,Italy <malesani@sissa.it>
D. Malesani (SISSA/ISAS), P. D'Avanzo (INAF/OABr), G. Chincarini (Univ.
Milano-Bicocca), G. Tagliaferri, S. Campana, S. Covino, D. Fugazza
(INAF/OABr), A. Fernandez-Soto (Univ. Valencia), M. Della Valle
(INAF/OAA), L.A. Antonelli, F. Fiore, S. Piranomonte, and L. Stella
(INAF/OAR), report on behalf of the MISTICI collaboration:
We observed the afterglow of GRB 060116 (Campana et al., GCN 4519;
Barthelmy et al., GCN 4531). Observations were carried out with the ESO
NTT telescope in the J and Ks filters. Observations were taken almost
simultaneously to our VLT I-band observations (D'Avanzo, Malesani &
Antonelli, GCN 4532), that is ~17 h after the GRB.
We detect the afterglow (Kocevski, Bloom & McGrath, GCNs 4528, 4540) in
the J and Ks filters. Calibration was performed against the 2MASS
survey. Comparing our measurements to the limit derived by the VLT
images, we measure the following colors after correcting for the
Galactic absorption (E(B-V) = 0.263):
J-K = 2.5 +- 0.3;
I-J > 2.9.
These colors are very red. If the I-band nondetection is interpreted as
a dropout, the inferred redshift is z ~ 6. The very red J-K color may in
this case suggest some rest-frame dust absorption, as also hinted by the
large column density present in the X-ray spectrum (Campana et al., GCN
4529). Alternatively, an even larger redshift (z~7-8) may suppress part
of the J-band emission.
With the present dataset, however, dust emission at lower redshift
cannot be excluded.
Further observations and analysis are in progress.
We acknowledge the excellent support of the ESO staff, in particular
Michael Sterzik and Cedric Foellmi.
This message can be cited.
GCN Circular 4540
Subject
GRB 060116: UKIRT IR Observations
Date
2006-01-18T04:20:13Z (20 years ago)
From
Daniel Kocevski at UC Berkeley <kocevski@berkeley.edu>
D. Kocevski, J. S. Bloom (UC Berkeley), and E. J. McGrath (UH
Institute for Astronomy) report on behalf of a larger collaboration:
"Repeat imaging of the field of GRB060116 with the United Kingdom
Infra-Red Telescope (UKIRT) at Mauna Kea begining at 07:28:37.44 UTC
on Jan 17th shows that the IR source reported by Kocevski et. al.
(GCN 4528) is no longer detected in our images. These observations
are consistent with the results reported by Malesani et. al. (GCN
4532) and confirms the variability of the source in the J band. An
image of the source and it's subtraction from the Jan 17th data can
be found at: http://spacibm.rice.edu/~kocevski/sub.jpg"
Daniel Kocevski
kocevski@berkeley.edu
www.kocevski.com
Astrophysics, UC Berkeley
832.423.5881
GCN Circular 4537
Subject
GRB 060116: PROMPT Observations
Date
2006-01-17T17:55:21Z (20 years ago)
From
Melissa Nysewander at UNC,Chapel Hill <mnysewan@astro.unc.edu>
M. Nysewander, A. LaCluyze, D. Reichart, J.A. Crain, A. Foster, K. Ivarson,
J. Haislip, C. MacLeod and J. Kirschbrown report on behalf of the UNC team
of the FUN GRB collaboration:
We observed the error region of GRB 060116 (Campana et al., GCN 4519) with
five of the PROMPT telescopes simultaneously in UBg'r'i'Iz' beginning 16.2
hours after the burst under the automated control of SkyNet. Each exposure
is 80 s long; the table below gives details of the observations:
Filter Telescope Start (UT) Stop (UT) # Exp Total (hr)
U P2 00:47:38 07:52:08 272 6.04
B P5 03:37:19 06:30:20 114 2.53
g' P3 02:59:30 04:39:18 66 1.47
r' P4 00:47:41 07:53:25 163 3.62
I P1 01:44:18 07:52:13 245 5.44
i' P4 03:38:24 06:27:06 115 2.56
z' P5 00:47:40 07:53:14 161 3.58
In a 100 x 80s stack, at a mean time of 19.1 hours after the burst, we do
not detect the candidate afterglow (Kocevski et al., GCN 4528) down to a
3-sigma limiting magnitude of I = 21.6 based on 5 USNO-B1.0 magnitudes.
PROMPT is currently being built and commissioned at CTIO.
GCN Circular 4532
Subject
GRB 060116: VLT optical observations
Date
2006-01-17T05:59:55Z (20 years ago)
From
Daniele Malesani at SISSA-ISAS,Trieste,Italy <malesani@sissa.it>
P. D'Avanzo (INAF/OABr), D. Malesani (SISSA/ISAS), L.A. Antonelli (INAF/OABr), report
on behalf of the MISTICI collaboration:
We observed the field of GRB 060116 (Campana et al., GCN 4519; Barthelmy
et al., GCN 4531) with the ESO-VLT UT2 equipped with FORS 1. Observations
were carried out in the R and I filters, starting on Jan 17.069 UT (17 h
after the burst).
The object reported by Kocevski, Bloom & McGrath (GCN 4528) is not
detected in our images down to a limiting magnitude I > 24.5 and R > 24.9
(3 sigma, calibrated against the USNO-B1 catalog).
Our non detection indicates that the candidate object by Kocevski et al.
(GCN 4528) is very likely the J-band afterglow of GRB 060116, which faded
significantly between the two observations.
We further note a faint, red object inside the XRT error box (Campana et
al., GCN 4522, 4529), at the coordinates (0.3" arcsec error):
alpha(J2000) = 05:38:46.170;
delta(J2000) = -05:26:15.08.
This is 2.5" away of the afterglow position (Kocevski et al., GCN 4528).
A finding chart in the I filter is posted at the following URL:
http://www.merate.mi.astro.it/~davanzo/GRB/grb060116_find_I.jpeg
This message can be cited.
[GCN OPS NOTE(18jan06): Per author's request, the affiliation was added to
the Malesani author.]
GCN Circular 4531
Subject
GRB 060116: Refined analysis of the Swift-BAT burst
Date
2006-01-17T03:15:36Z (20 years ago)
From
Scott Barthelmy at NASA/GSFC <Scott@lheamail.gsfc.nasa.gov>
S. Barthelmy (GSFC), L. Angelini (GSFC-JHU), L. Barbier (GSFC),
M. Chester (PSU), J. Cummings (GSFC/NRC), E. Fenimore (LANL),
N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/NRC), G. Sato (ISAS), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
Using the data set from T-299 to T+303 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 060116 (trigger #177533)
(Compana, et al., GCN 4519). The BAT ground-calculated position is
RA,Dec = 84.699,-5.449 deg {5h 38m 47.8s, -5d 26' 56.0"} (J2000) +- 1.7 arcmin,
(radius, sys+stat, 90% containment). The partial coding was 20%.
The lightcuve has one peak centered on T+20 sec. There is very weak emission
starting as early as ~T-40 sec. The event is over by ~T+90 sec.
T90 (15-350 keV) is (113 +- 10) sec (estimated error including systematics).
The power law index of the time-averaged spectrum is 1.44 +- 0.18.
The fluence in the 15-150 keV band is (2.6 +- 0.3) x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+36.08 sec in the 15-150 keV
band is (1.1 +- 0.3) ph/cm2/sec. All the quoted errors are at the 90%
confidence level.
GCN Circular 4529
Subject
GRB 060116: XRT refined analysis
Date
2006-01-16T22:14:54Z (20 years ago)
From
Sergio Campana at INAF-OAB <campana@merate.mi.astro.it>
S. Campana (INAF-OAB), M. Perri (ASDC), P. Romano (INAF-OAB), D.N. Burrows
(PSU), J. Norris (GSFC), K. Hurley (Berkeley) report:
"We have analyzed the first four orbits of XRT data from GRB 060116
(Campana et al., GCN 4519). The GRB afterglow is detected at a mean count
rate of 0.099+/-0.004 count/s during a 5545 s Photon Counting mode
observation. Close to the GRB afterglow (1.2 arcmin) there is a fainter
source (0.017+/-0.002 count/s) coincident with an M4 star. The best fit
position for the GRB afterglow is:
RA(J2000) = 05h 38m 46.22s,
Dec(J2000) = -05d 26m 11.9s
with error radius 3.7 arcsec, less than 1 arcsec from the one reported
in Campana et al. (GCN 4522) based on a shorter observation. This
position is also 1.5 arcsec from the source reported by Kocevski et al.
(GCN 4528).
The X-ray light curve is fading and its decay law is consistent with a
power-law with slope of -0.95+/-0.07 (90% confidence level). No strong
flare activity is observed.
The X-ray spectrum can be fit with an absorbed power law model
with photon index of 2.1+/-0.3 and a column density of (8.1+/-2.5)E21
cm-2, higher than the Galactic hydrogen column density in the direction
of the burst (NH_gal=2.0E21 cm-2 at b=-19). The mean 0.5-10 keV unabsorbed
flux is 9E-12 erg cm-2 s-1. Fixing the Galactic column density to
the above value we can constrain the GRB redshift to be z<3.2 or z>5.4
(90% c.l., and NH(z)>4E21 cm-2).
If the burst continues to decay at the current rate we estimate an XRT
count rate of 2E-3 counts/s at T+24hr, which corresponds to an observed
0.5-10 keV flux of ~3E-13 ergs cm-2 s-1.
GCN Circular 4528
Subject
GRB 060116: IR Candidate Afterglow
Date
2006-01-16T21:56:50Z (20 years ago)
From
Daniel Kocevski at UC Berkeley <kocevski@berkeley.edu>
D. Kocevski, J. S. Bloom (UC Berkeley), and E. J. McGrath (UH
Institute for Astronomy) report on behalf of a larger collaboration:
"Target of opportunity imaging of the field of GRB060116 on the
United Kingdom Infra-Red Telescope (UKIRT) at Mauna Kea begining at
09:42:00 UTC has revealed an IR source somewhat fainter than the
2MASS detection level consistent with the XRT position reported in
GCN 4522. The position (J2000) is:
05:38:46.280
-05:26:13.14
(+/- 200 mas).
with an estimated magnitude of J = 18.3 +/- 0.1 relative to 2MASS.
We cannot confirm variability at this time, but further observations
are planned. An image of the source can be found at http://
bloom1.ugastro.berkeley.edu/~kocevski/grb060116_ukirt.ps"
Daniel Kocevski
kocevski@berkeley.edu
www.kocevski.com
Astrophysics, UC Berkeley
832.423.5881
GCN Circular 4527
Subject
GRB 060116: Swift/UVOT upper limits
Date
2006-01-16T17:24:21Z (20 years ago)
From
Tracey Poole at MSSL <tsp@mssl.ucl.ac.uk>
T. S. Poole (UCL-MSSL), S. Campana (INAF-OAB), J. Nousek (PSU), N.
White (GSFC), N. Gehrels (GSFC) on behalf of the Swift/UVOT team.
The Swift/UVOT began observing the field of GRB060116 (BAT
Trigger=177533, S. Campana, et. al, GCN 4519) at 08:39:46, 154s after
the BAT trigger. No new source is detected at the XRT position (S.
Campana, GCN 4522) in coadded images with any of the filters. The
following 3-sigma magnitude upper limits are not corrected for Galactic
extinction; E(B-V) = 0.264.
Filter T_range(s) T_exp(s) 3sigma(mag)
V 154-610 219.6 19.2
B 361-706 219.6 20.2
W1 639-802 39.6 18.5
M2 614-778 38.6 18.5
W2 567-731 39.6 18.5
Where T_range is time post-trigger, and T_exp is the exposure time of
the observation. A 6 arcsec radius was used for all filters.
This message may be cited.
GCN Circular 4524
Subject
GRB 060116 : Lulin optical limit
Date
2006-01-16T16:32:11Z (20 years ago)
From
Kuiyun Huang at IANCU <d919003@astro.ncu.edu.tw>
M. Yang, Y.T. Chen, H.C. Lin, K.Y. Huang, W.H. Ip (NCU),
Y. Urata(RIKEN), Y. Qiu (BAO), Y.Q. Lou (THCA) on behalf of EAFON
report:
" We observed the error region of GRB 060116 (Campana et al., GCN
4519) using 1-m telescope at Lulin Observatory, Taiwan. After the
twliglights, the I and R band observations were started at 11.16 UT(
about 2.9 hours after burst). No variable source was detected in the
BAT and XRT error region(Campana et al. GCN 4522) at our co-add I and
R images. The limiting magnitude of I and R band were calibrated
against USNO-B1.0 catalog (I and R, respectively).
Mid-UT(hrs) Exp-time Filter limiting mag. (3-sigma)
----------------------------------------------------------
3.01 3x300s I ~20.1
3.10 3x300s R ~21.0
4.77 3x300s I ~20.0
This message may be cited."
GCN Circular 4523
Subject
GRB 060116: ROTSE-III Optical Limits
Date
2006-01-16T15:12:28Z (20 years ago)
From
Eli Rykoff at U of Michigan/ROTSE <erykoff@umich.edu>
E.S. Rykoff (U Mich), S.A. Yost (U Mich), H. Swan (U Mich), report on
behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
060116 (Swift trigger 177533, Campana, et al, GCN 4519), producing
images beginning 9.0 s after the GCN notice time. An automated response
took the first image at 08:38:46.0 UT, 78.8 s after the burst, under
fair conditions. We took 10 5-sec, 10 20-sec and 70 60-sec eposures.
These unfiltered images are calibrated relative to USNO A2.0 (R).
Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma BAT error circle, or in the XRT error circle (Campana, et al,
GCN 4522) for both single images and coadding into sets of 10.
Individual images have limiting magnitudes ranging from 15.6-16.9; we
set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
08:38:46.0 08:38:51.0 5 16.1 78.8 N
08:38:46.0 08:39:55.0 69 17.7 78.8 Y
08:40:07.6 08:44:50.7 283 18.0 160.4 Y
GCN Circular 4522
Subject
GRB060116: XRT position
Date
2006-01-16T12:46:40Z (20 years ago)
From
Sergio Campana at INAF-OAB <campana@merate.mi.astro.it>
S. Campana (INAF-OAB), M. Perri (ASDC), P. Romano (INAF-OAB),
D.N. Burrows (PSU) on behalf of the Swift XRT team:
We have analyzed the first orbit of XRT data from GRB 060116
(trigger 177533; Campana et al., GCN 4519). A 1364 s Photon Counting
mode image provides a refined XRT position:
RA(J2000) = 05h 38m 46.20s,
Dec(J2000) = -05d 26m 12.8s
with an uncertainty of 3.7 arcsec (90% containment). This position
includes the latest XRT boresight correction. This position is 0.8
arcmin from the BAT position.
GCN Circular 4521
Subject
GRB060116: Faulkes North observation
Date
2006-01-16T11:18:20Z (20 years ago)
From
Cristiano Guidorzi at ARI,Liverpool JMU <crg@astro.livjm.ac.uk>
C. Guidorzi, A. Melandri, I. A. Steele, C.G. Mundell, A. Monfardini,
A. Gomboc, C.J. Mottram, R.J. Smith, M.F. Bode (Liverpool JMU),
P. O'Brien, E. Rol, N. Bannister (Leicester) report:
"The 2-m Faulkes Telescope North robotically followed up GRB060116
(SWIFT trigger 177533) 18.5 min after the GRB trigger time.
The 4.6'x 4.6' field of view covered about 75% of the BAT error circle.
The automatic "detection mode" procedure did not find any afterglow
candidate brighter than R~19 mag (vs USNOB1) from a 3x10s exposure.
The visual extinction of the field is A_V~0.8 according
to the Schlegel et al. maps.
Further automated observations were conducted immediately following the
"detection mode" exposures in B, R and SDSS-I filters.
Manual inspection of subsequent datasets
reveals no afterglow candidate down to the DSS limit."
GCN Circular 4519
Subject
GRB 060116: Swift-BAT detection of a burst
Date
2006-01-16T09:06:54Z (20 years ago)
From
Scott Barthelmy at NASA/GSFC <Scott@lheamail.gsfc.nasa.gov>
S. Campana (INAF-OAB), S. Barthelmy (GSFC), N. Gehrels (GSFC),
C. Gronwall (PSU), J. Kennea (PSU), C. Markwardt (GSFC/UMD),
K. Page (U Leicester), D. Palmer (LANL), M. Perri (ASDC)
on behalf of the Swift team:
At 08:37:27 UT, Swift-BAT triggered and located GRB 060116 (trigger=177533).
The spacecraft slewed immediately. The BAT on-board calculated location is
RA,Dec 84.699d,-5.449d {05h 38m 48s,-05d 26' 54"} (J2000), with an uncertainty
of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve shows
a multi-peak structure with a total duration of ~35 sec. The peak count rate
was ~600 counts/sec (15-350 keV), at several times after the trigger.
XRT began observing the field at 08:40:00.75 UT, 154 sec after the BAT trigger.
The on-board detection algorithm did not centroid on a source due to
insufficient counts so no prompt X-ray position is available. The XRT prompt
spectrum and lightcurve show no signficant X-ray emission in the field,
suggesting that any X-ray counterpart to this burst is faint. Further analysis
will require processing of the XRT full telemetry data following the next
ground station contact at 09:32 UT.
UVOT took a finding chart exposure of 200 seconds with the V filter
starting 153 seconds after the BAT trigger. No afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers
25% of the BAT error circle. The typical 3-sigma upper limit has been
about 18th mag. The 8'x8' region for the list of sources generated
on-board covers 100% of the BAT error circle. The list of sources is
typically complete to about 18.0 mag. No correction has been made for
the expected visual extinction of about 0.9 magnitudes.