image overlap message for exposure 1 of trigger 856977
uvot_overlap.pl vrs. 2010-12-20b fem started at 180829d07h36m06s758043usUT
The observation of trigger 856977 started 2018-08-28T19:00:00.2
Examining file ./856977_g145_uvot_sky_image.fits
The exposure ID is 557175600
The exposure time is 30.106 (seconds)
The filter is WHITE.
The uvot region is centered at (268.7125,-25.7999) with a roll angle of 269.5
It is square with sides of 2.68 arc min. for an area of 7.17 sq arc min
The BAT error circle is centered at (268.7000,-25.8000) with a radius of 3.000 arc min
This is 0.673 arc min from the center of the uvot region
The area of the BAT error circle is 28.27 sq. arc min
The UVOT/BAT overlap is 7.17 sq. arc min or 0.25 of the BAT error circle
The XRT error circle is centered at (268.7182,-25.7981) with a radius of 0.028 arc min
This is 0.325 arc min from the center of the uvot region
The area of the XRT error circle is 0.003 sq. arc min
The UVOT/XRT overlap is 0.003 sq. arc min or 1.00 of the XRT error circle
image afterglow message for exposure 1 of trigger 856977
find_uvot_ag.pl vrs. 2017-02-17 fem started at 180829d07h36m08s098989usUT
Observation start time is 2018-08-28T19:00:00.2
Examining file ./856977_g145_uvot_catalog_image.fits
The exposure ID is 557175600
The exposure is 30.106 sec.
The bin size is 2 pixels
The filter is WHITE
There are 29 detected source(s) for 856977_g145
Aspect correction adds 0.00017 degrees (0.042 sec of time = 0.56 arc sec) to RA
Aspect correction adds 0.00020 degrees ( 0.72 arcsec) to Dec
Total aspect correction is 0.92 arcsec
Star catalogs centered at 268.7112 , -25.7956 with radius 2.75 arc min.
n_usno: 307 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 28 matched entries is 0.576" for 856977_g145
Mean and std. dev of mag. difference (MAG_DELTA) are 1.450 and 0.568 for 856977_g145
Found 1 entries without IDs and 1 entries that are acceptable afterglow candidates for 856977_g145.
Acceptable entries have no ID, XRT distances < 5", and are > 0.8*(80 - 10*(mag-6))" from any bright star
from any bright star and >21.6" from other rejected sources.
Magnitude criteria will be applied later.
BAT distances are from RA=268.7000 (17:54:48.00) DEC=-25.8000 (-25:48:00.0)
XRT distances are from RA=268.7182 (17:54:52.36) DEC=-25.7981 (-25:47:53.3)
-----------------
Entry 12 in the list of sources is a candidate afterglow for 856977_g145 with genie
ra=268.71012 (17:54:50.43) dec=-25.78646 (-25:47:11.2) +/- 0.6" mag=16.76+/-0.15
dist=49.5 REFID=7 major=0.9 minor=0.9 flag=3 (neighbor+blended)
*** The position of this source is inconsistent with the XRT position.
The position is 58.8 arc sec from the BAT position.
Found 5 entries in star catalog(s) within 20.0" of the candidate.
printing all entries
(Entries within 2 arc sec of a source list entry are considered a match)
RA Dec Sep. Match USNO/ USNO-B USNO-R USNO-V
GSC GSC-F GSC-J GSC-V
268.7124 -25.7896 13.4 -1 USNO-B1 18.45 16.24 17.22
268.7105 -25.7888 8.7 -1 USNO-B1 19.07 16.12 17.43
268.7121 -25.7859 6.7 -1 USNO-B1 18.17 16.01 16.97
268.7100 -25.7858 2.5 -1 USNO-B1 15.09 13.29 14.09 *
268.7097 -25.7854 4.2 -1 USNO-B1 15.04 99.99 99.99
Due to star catalog entries marked with *, this is probably NOT the afterglow
These entries are within 3.5" or brighter than 12 mag
Found 2 entries in star catalog(s) within 10" of the XRT position.
RA Dec Sep. Match USNO/ USNO-B USNO-R USNO-V
GSC GSC-F GSC-J GSC-V
268.7156 -25.7988 8.6 -1 USNO-B1 18.91 16.14 17.37
268.7189 -25.7989 3.5 -1 USNO-B1 99.99 17.64 99.99
The closest star is 3.46" away.
List UVOT sources within 10" of the XRT position:
Matched source ra=268.71561 (17:54:51.75) dec=-25.79881 (-25:47:55.7) +/- 0.8" mag=19.03+/-0.22 dist=8.7 REFID=18 flag=0
There are 21138.385 counts in the bkg source region of 5427.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 3.895 counts/pixel (5-sig UL in 4" is 18.87 mag) for 856977_g145
There are 814.85315 counts in the xrt source region of 200.00000 pixels.
Rate in xrt region with 8 arcsec radius is 4.074 counts/pixel for 856977_g145
There are 4308.8027 counts in the xrt_bkg source region of 1101.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 3.914 counts/pixel (5-sig UL in 4" is 18.87 mag) for 856977_g145
There are no candidates inside BAT error circle, but outside XRT error circle.
Good candidates have no ID, acceptable profiles,
mag between 9.01 and 19.42, XRT distances < 5",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 0 good candidate(s) found.
Region file: 856977_557175600_180829d07h36m08s098989usUT_bkg.region
# Region file format: DS9 version 3.0
global color=red font="helvetica 10 normal" select=1 edit=1 move=1 delete=1 include=1 fixed=0 source
fk5;circle(268.7125,-25.7999,45")
fk5;-circle(268.715606395099,-25.7988142767494,6")
fk5;-circle(268.721596609131,-25.7974998293156,6")
fk5;-circle(268.713045510584,-25.7992322655016,6")
fk5;-circle(268.719279969124,-25.7944664324745,6")
fk5;-circle(268.714876486242,-25.807936730815,6")
fk5;-circle(268.719703528201,-25.7892352899102,6")
fk5;-circle(268.726287176775,-25.8065046763287,6")
fk5;-circle(268.712413333983,-25.7895982553997,6")
fk5;-circle(268.71011885522,-25.7864571648419,6")
fk5;-circle(268.702042534422,-25.7927181134753,6")
fk5;-circle(268.700254274099,-25.8043051456513,6")
Region file: 856977_557175600_180829d07h36m08s098989usUT_xrt.region
# Region file format: DS9 version 3.0
global color=red font="helvetica 10 normal" select=1 edit=1 move=1 delete=1 include=1 fixed=0 source
fk5;circle(268.71817,-25.79814,8")
Region file: 856977_557175600_180829d07h36m08s098989usUT_xrt_bkg.region
# Region file format: DS9 version 3.0
global color=red font="helvetica 10 normal" select=1 edit=1 move=1 delete=1 include=1 fixed=0 source
fk5;circle(268.71817,-25.79814,25")
fk5;-circle(268.71817,-25.79814,15")
fk5;-circle(268.721596609131,-25.7974998293156,6")
fk5;-circle(268.713045510584,-25.7992322655016,6")
fk5;-circle(268.719279969124,-25.7944664324745,6")
image paragraph message for exposure 1 of trigger 856977
WARNING -- because of the LARGE EXTINCTION, results should be used cautiously.
1 source(s) near the XRT position were rejected as afterglow candidate(s). See
notes for details.
------ Start for Possible Stand-alone Circular ----
In response to GRB180828 (Swift/BAT trigger 856977) at 18:57:34 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 30 seconds with the White filter
starting 123 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.
Results from the list of sources generated on-board are not available at this
time. No correction has been made for the large, but uncertain, extinction
expected.
------- notes for trigger 856977 ------
uvot_gcn_auto.pl vrs. 2016-09-07 fem at 180829d07h36m10s767855usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=856977
-expid=557175600 -meonly -msg_image
Results from standard processing of UVOT TDRSS data for this trigger should be
available at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/856977/
Links to data for all triggers can be found at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/
Large extinction of 80.58 found for bat position. Unreliable extinction found
for xrt position. XRT position found for Genie image. BAT position found.
UVOT exposure began at MET 557175600.21904 or about 2018:240:18:59:55 UT
No information found about the number of stars in the star catalog for srclist
region.
Found 29 source(s) in Genie image catalog. 1 source(s) are within 10.0" of the
xrt position. Found 1 Genie image source(s) without IDs. There are 0 good
candidate(s) in the Genie image catalog. Good candidates must be brighter than
19.42 mag. Found 303 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 27% of the Genie image region.
Genie image analysis:
Found 21138.4 counts in the large background region of 5427.0 pixels or a rate
of 3.895 counts/pixel in a radius of 45.0 arcsec. Based on this background, the
typical 5-sigma UL at a random point in the Genie image is 18.86 mag. for a
4-arcsec aperture.
Found 814.9 counts in the XRT position region of 200.0 pixels or a rate of
4.074 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is 1.073 +/- 1.031 (1-sigma) cps or
19.70 mag and a range from 18.97 to 23.22 mag. The 3-sigma UL at the XRT
position is 4.167 cps or 18.23 mag.
Found 1 Genie source(s) within 10.0" of the XRT position. The brightest such
source has ra= 268.7156 dec= -25.7988 mag=19.03 sep=8.66". The closest Genie
source has ra= 268.7156 dec= -25.7988 mag=19.03 sep=8.66".
Report rejected UVOT sources within 10 arcsec XRT position.
Such sources are usually NOT the afterglow.
****THIS SOURCE NEAR XRT POSITION WAS REJECTED--USE WITH CAUTION****
UVOT took a finding chart exposure of 30 seconds with the White filter
starting 123 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 17:54:51.75 = 268.71561
DEC(J2000) = -25:47:55.7 = -25.79881
with a 90%-confidence error radius of about 0.81 arc sec. This position is 8.66
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.03 with a 1-sigma error of about 0.22. No correction has been made for the
large, but uncertain, extinction expected.
All AG candidates sorted by magnitude for the current finding chart.
(U/V/White SRCLIST mags < 17.5/17.5/18.5 are reliable. Mag > 18.5/18.5/19.5 are
not. Others are uncertain.)
(U/V/White Genie image mags < 18.0/18.0/19.0 are reliable. Mag > 19.0/19.0/20.0
are not. Others are uncertain.)
(Magnitudes followed by * have been corrected for exposure.)
---MET--- -dt- filter ---RA-- ---DEC--- -MAG/Limit Dist(") Source Asp.Corr?
557175600 123 WHITE srclist data are not available.
557175600 123 WHITE image found no candidates.
List afterglow candidates for other finding charts.
557178836 3359 ? srclist data are not available.
557178836 3359 WHITE image found no candidates.
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: white
GRB_DEC: -25.79814
GRB_ERROR: 5
GRB_RA: 268.71817
IMAGE_START_TIME: 18:59:55
MAGNITUDE: 18.2
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT