GRB 060522
GCN Circular 5150
Subject
GRB 060522: Swift detection of a burst with possible optical afterglow
Date
2006-05-22T02:47:17Z (19 years ago)
From
Derek Fox at PSU <dfox@astro.psu.edu>
D. B. Fox (PSU), J. R. Cummings (NASA/ORAU), N. Gehrels (NASA/GSFC),
S. T. Holland (GSFC/USRA), S. D. Hunsberger (PSU),
J. A. Kennea (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), F. E. Marshall (NASA/GSFC),
D. C. Morris (PSU), D. M. Palmer (LANL) and
M. Stamatikos (NASA/GSFC/ORAU) report on behalf of the Swift Team:
At 02:11:18 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060522 (trigger=211117). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA,Dec 322.951, +2.876 {21h 31m 48s, +02d 52' 33"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). Since this was a 64-sec BAT image trigger, there is not
enough information in the light curve at this time to describe the time
profile of the burst. The peak count rate was ~500 counts/sec (15-350 keV),
at ~5 sec after the trigger.
The XRT began taking data at 02:13:40 UT, 142 seconds after the BAT
trigger. The XRT on-board centroid algorithm did not find a source in
the image, however analysis of initial downlinked data shows the
presence of an uncatalogued point source at the following
coordinates: RA (J2000) = 21:31:44.9, Dec(J2000) = +02:53:08.5, with
an error radius of 4.0 arcseconds (90% containment). This source is
61 arcseconds from the BAT position.
The UVOT began a 100 s white exposure at 02:13:47. A point source is
detected in the XRT error circle with a white magnitude of 19.7. This
source is not present in the DSS. The coordinates of this source are
21:31:44.8, +02:53:10 (J2000) with an uncertainty of +/- 0.6 arcsec
(90% containment).
GCN Circular 5151
Subject
GRB 060522: TNG optical observations
Date
2006-05-22T05:22:51Z (19 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo (INAF/OAB), S. Piranomonte (INAF/OARm), A. Magazzu`, G.
Mainella (INAF/TNG), report on behalf of a larger collaboration:
We observed the field of GRB 060522 (Fox et al. GCN 5150) with the 3.6m
TNG telescope located in Canary Islands. One R-band image was obtained
with TNG+DOLoRes, starting on May 22.1556 UT (about 1.5 hours after the
burst) for a total exposure time of 10 minutes.
We see a bright object at the following position:
R.A.= 21:31:44.8, Dec +02:53:10.35 +/- 0.20 arcsec (J2000)
with a magnitude of R = 20.6 +/- 0.1 (vs USNO@ESO catalog)
We note that the position of this object is consistent with the UVOT
afterglow candidate reported by Fox et al. (GCN 5150).
We thank the observing staff at TNG.
GCN Circular 5152
Subject
GRB 060522: REM NIR observations
Date
2006-05-22T10:20:41Z (19 years ago)
From
Stefano Covino at Brera Astronomical Observatory <stefano.covino@brera.inaf.it>
S. Vergani, P. D'Avanzo, S.Covino, E. Molinari, G. Chincarini, F.M.
Zerbi, V. Testa, G. Tosti, F. Vitali, P. Conconi, L.A. Antonelli,
G. Cutispoto, G. Malaspina, L. Nicastro, E. Palazzi, E. Meurs, and
P. Goldoni report on behalf of the REM/ROSS team:
We imaged the field of GRB 060522 (Fox et al., GCN 5150) with the
robotic 60-cm REM telescope located at La Silla (Chile) under
mediocre weather conditions. A first set of observations was
performed automatically in the near infrared (J, H, K, z bands)
starting on May 22.2306 UT (about 3.3 hours after the burst). Then,
we took a set of 20x100s H band images starting on May 22.2785 UT
(about 4.5 hours the burst).
Preliminary analysis of both the datasets does not show any new
source down to H = 16.5 and H=17.0 (3-sigma upper limits)
respectively, at the position of the candidate optical afterglow
reported by Fox et al. (GCN 5150) and D'Avanzo et al. (GCN 5151).
This message is citeable.
[GCN OPS NOTE(24may06): Per author's request, Antonelli was added
to the author list.]
GCN Circular 5153
Subject
GRB 060522: Swift-BAT Refined Analysis
Date
2006-05-22T13:25:26Z (19 years ago)
From
Hans Krimm at NASA-GSFC <krimm@milkyway.gsfc.nasa.gov>
H. Krimm (GSFC/USRA), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), M. Koss (GSFC/UMD), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU),
G. Sato (GSFC/JSPS/USRA), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
Using the data set from T-239.0 to T+730.1 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 060522 (trigger #211117)
(Fox, et al., GCN 5150). The BAT ground-calculated position
is (RA,Dec) = 322.953, 2.889 deg {21h 31m 48.8s, 2d 53' 18.9"} (J2000)
+- 1.5 arcmin, (radius, sys+stat, 90% containment). The partial
coding was 75%.
The mask-weighted light curve shows two broad peaks, the first with a FRED-like
profile from T+0 to T+20 sec and the second with a square profile from T+25 to
T+80 sec. Nearly all emission is below 100 keV. T90 (15-350 keV) is
69 +- 5 sec (estimated error including systematics).
The time-averaged spectrum from T+0.2 to T+76.9 is best fit by
a simple power-law model. The power law index of the time-averaged
spectrum is 1.59 +- 0.15. The fluence in the 15-150 keV band is
1.1 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from
T+4.41 sec in the 15-150 keV band is 0.6 +- 0.2 ph/cm2/sec. All the quoted
errors are at the 90% confidence level.
GCN Circular 5154
Subject
GRB 060522: Swift/XRT Team refined analysis
Date
2006-05-22T17:43:27Z (19 years ago)
From
Jamie A. Kennea at PSU/Swift-XRT <kennea@astro.psu.edu>
J. A. Kennea, D. C. Morris and D. Fox (PSU) report on behalf of the
Swift/XRT Team:
We have analysed the first 4 orbits of Swift/XRT data of GRB 060522 (Fox
et al., GCN 5150) which equates to 4496+126 seconds of data. We find a
refined XRT position for this burst of:
RA(J2000) = 21:31:44.91
Dec(J2000) = +2:53:08.14
with an error of 3.7 arcseconds radius (90% containment). This position is
58 arcseconds from the refined BAT position quoted by Krimm et al. (GCN
5153), 0.4 arcseconds from the original XRT position from Fox et al., and
2.8 arcseconds from the optical counterpart reported by UVOT and confirmed
by TNG (D'Avanzo et al., GCN 5151).
The afterglow shows several states: from T+150 to T+190 the lightcurve was
bright (~6 XRT c/s) and relatively flat, at T+190 the lightcurve breaks
and rapidly decays with a power-law slope of -4.0. The lightcurve breaks
again at T+233s and flattens to a slope of -1.77. Centered at T+540 there
is a small flare in the lightcurve. From T+1000s to T+5500s there is no
data in the lightcurve, however the lightcurve appears to have flattened
in this time. Data from T+5000 onwards shows the lightcurve is decaying
with a slope of -1.3.
The average spectrum of the burst is well fit by an absorbed power-law
model. The parameters of this fit are N_H = (4.6 +/- 2.5) x 10^20 cm^-2,
and a power-law photon index of 1.97 +/- 0.21 (errors 90% confidence). The
expected galactic absorption from this position in the sky is 4.83 x 10^20
cm^-2, so there is no evidence of excess absorption in this burst
afterglow.
The prediction for the brightness of the burst 24 hours after the BAT
trigger is approximately 2x10^-3 XRT Counts/s which is equivalent to a
flux of ~7x10^-14 erg/s/cm^2 (0.2-10 keV).
This circular is an official product of the Swift/XRT team.
GCN Circular 5155
Subject
GRB060522: z = 5.11 Keck-LRIS Redshift
Date
2006-05-22T22:17:46Z (19 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko (Caltech), E. Berger (Carnegie), S. G. Djorgovski, A. A.
Mahabal (Caltech), and D. B. Fox (Penn State) report on behalf of a
larger collaboration:
We have observed the location of the afterglow of GRB060522 (Fox et al.,
GCN 5150; D'Avanzo et al., GCN 5151) with the Low-Resolution Imaging
Spectrometer mounted on the 10-m Keck I telescope. We obtained an 1800
s spectrum shortly before morning twilight at a mean epoch of May 22.65
UT (~ 12.5 hr after the burst).
We find a prominent absorption feature centered around ~ 7425 A, with a
strong depression in flux blue-ward of this break. Identifying this as
the Lyman-alpha break and fitting a DLA profile to the spectrum, we find
z = 5.11 +/- 0.01 and log(nH) = 20.5 +/- 0.5.
At this redshift and using a 15-150 keV fluence of 1.1e-6 (Krimm et al.,
GCN 5153), we find the prompt emission isotropic energy release from
GRB060522 is 5.1e52 ergs.
GCN Circular 5158
Subject
GRB 060522: Swift/UVOT Observations of the Optical Afterglow
Date
2006-05-23T16:26:10Z (19 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <sholland@milkyway.gsfc.nasa.gov>
GRB 060522: Swift/UVOT Observations of the Optical Afterglow
S. T. Holland (NASA/GSFC & USRA) reports on behalf of the Swift/UVOT
team:
The Swift UVOT began observing GRB 060522 (trigger #211117,
Fox et al., GCN Circular 5150) 129 seconds after the BAT trigger.
We detect the UVOT optical transient reported in the above Circular
in the White filter. The J2000 coordinates of the afterglow are
RA = 21:31:44.85
Dec = +02:31:44.9
with an uncertainty of +/- 0.6 arcseconds (90% containment).
Magnitudes and 3-sigma upper limits are reported below.
Midpoint Coadded
Filter Time Exposure Mag Err
(sec) (sec)
White 198 100 19.65 0.21
White 749 9 >18.4 3-sigma upper limit
White 927 98 >20.3 3-sigma upper limit
White 6266 197 >20.9 3-sigma upper limit
White 74,157 4766 >22.1 3-sigma upper limit
V 452 400 >20.1 3-sigma upper limit
V 792 20 >17.6 3-sigma upper limit
V 1100 231 >19.5 3-sigma upper limit
V 18,351 1967 >20.8 3-sigma upper limit
B 3447 206 >20.7 3-sigma upper limit
U 18,315 1451 >21.0 3-sigma upper limit
UVW1 17,925 2904 >22.0 3-sigma upper limit
UVM2 17,533 1944 >21.9 3-sigma upper limit
UVW2 23,194 2001 >21.7 3-sigma upper limit
These data are consistent with the burst having a redshift of
z = 5.11 (Cenko et al., 2006, GCN Circular 5155). No correction
has been made for the Galactic reddening of E(B-V) = 0.05 mag
(Schlegel et al. 1998) along the line of sight to GRB 060522.
GCN Circular 5159
Subject
GRB 060522: Swift/UVOT Observations: Correction
Date
2006-05-23T18:16:22Z (19 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <sholland@milkyway.gsfc.nasa.gov>
GRB 060522: Swift/UVOT Observations: Correction
S. T. Holland (NASA/GSFC & USRA) reports on behalf of the Swift/UVOT
team:
There is an error in the coordinates of the optical afterglow
of GRB 060522 reported in Holland (2006, GCN Circular 5058). The
correct J2000 coordinates are
RA = 21:31:44.85
Dec = +02:53:10.8
with an uncertainty of +/- 0.6 arcseconds (90% confidence).
We apologize for the error and any inconvenience that
it may have caused.
GCN Circular 5232
Subject
GRB 060522: PROMPT Optical Limits
Date
2006-06-06T18:37:05Z (19 years ago)
From
Chelsea Louise MacLeod at UNC-Chapel Hill/PROMPT <chelseam@physics.unc.edu>
A. Smith, S. Parris, C. MacLeod, J. Harvey, M. Nysewander, D. Reichart,
report on behalf of the UNC team of the FUN GRB Collaboration:
Skynet observed the localization of the high-redshift GRB 060522 (Fox et
al., GCN 5150, Cenko et al., GCN 5155) with three of the 16" PROMPT
telescopes at CTIO and with 14.5" TTT in Colorado beginning 3.1 hours after
the burst:
Filter Start (UT) Stop (UT) Exposures Total (hr) Telescope
r' 05:17:02 09:39:04 74 x 80s 1.6 PROMPT-4
U 05:17:04 09:39:20 74 x 80s 1.6 PROMPT-3
z' 05:18:08 10:28:57 145 x 80s 3.2 PROMPT-5
+ 1 x 40s
i' 05:42:49 10:28:20 72 x 80s 1.6 PROMPT-4
g' 05:42:49 10:28:38 72 x 80s 1.6 PROMPT-3
V 07:29:06 09:37:22 22 x 160s 1.0 TTT
Red* 07:24:57 10:25:26 36 x 160s 1.6 TTT
* Approximates R band
We were unable to see the afterglow down to a 3-sigma limiting magnitude of
r' > 21.2 and z' > 20.9 at 4.2 hours and i' > 21.5 and z' > 21.3 at 4.9
hours after the burst.
GCN Circular 5352
Subject
GRB 060522: VLA observation
Date
2006-07-19T22:50:36Z (19 years ago)
From
Poonam Chandra at U Virginia/NRAO <pc8s@virginia.edu>
P. Chandra (UVA/NRAO), P. B. Cameron (Caltech), A. M. Soderberg (Caltech)
and D. A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB
Collaboration:
"We observed the field centered on the BAT position of the Swift burst GRB
060522 (GCN#5150) using the VLA at a frequency of 8.46 GHz and starting at
8.56 UT on July 18, about 57 days after the burst. There is no detection of
the GRB with 3-sigma upper limit of 57 microJy.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."