image overlap message for exposure 2 of trigger 856977
uvot_overlap.pl vrs. 2010-12-20b fem started at 180829d07h36m07s374747usUT
The observation of trigger 856977 started 2018-08-28T19:53:56.6
Examining file ./856977_g3381_uvot_sky_image.fits
The exposure ID is 557178836
The exposure time is 26.165 (seconds)
The filter is WHITE.
The uvot region is centered at (268.7174,-25.7993) 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 0.941 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 0.081 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 2 of trigger 856977
find_uvot_ag.pl vrs. 2017-02-17 fem started at 180829d07h36m13s035374usUT
Observation start time is 2018-08-28T19:53:56.6
Examining file ./856977_g3381_uvot_catalog_image.fits
The exposure ID is 557178836
The exposure is 26.165 sec.
The bin size is 2 pixels
The filter is WHITE
There are 23 detected source(s) for 856977_g3381
Aspect correction adds 0.00066 degrees (0.158 sec of time = 2.14 arc sec) to RA
Aspect correction adds 0.00138 degrees ( 4.97 arcsec) to Dec
Total aspect correction is 5.41 arcsec
Star catalogs centered at 268.7132 , -25.7966 with radius 2.62 arc min.
n_usno: 285 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 21 matched entries is 0.522" for 856977_g3381
Mean and std. dev of mag. difference (MAG_DELTA) are 1.345 and 0.422 for 856977_g3381
Found 2 entries without IDs and 2 entries that are acceptable afterglow candidates for 856977_g3381.
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 7 in the list of sources is a candidate afterglow for 856977_g3381 with genie
ra=268.71022 (17:54:50.45) dec=-25.78651 (-25:47:11.4) +/- 0.6" mag=16.82+/-0.15
dist=49.2 REFID=9 major=1.0 minor=0.8 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 13.1 -1 USNO-B1 18.45 16.24 17.22
268.7105 -25.7888 8.5 -1 USNO-B1 19.07 16.12 17.43
268.7121 -25.7859 6.5 -1 USNO-B1 18.17 16.01 16.97
268.7100 -25.7858 2.7 -1 USNO-B1 15.09 13.29 14.09 *
268.7097 -25.7854 4.5 -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
-----------------
Entry 15 in the list of sources is a candidate afterglow for 856977_g3381 with genie
ra=268.72885 (17:54:54.93) dec=-25.78007 (-25:46:48.3) +/- 0.7" mag=17.92+/-0.18
dist=73.7 REFID=4 major=1.0 minor=0.6 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 117.9 arc sec from the BAT position.
This source is near the edge of image (0.963)
Found 5 entries in star catalog(s) within 20.0" of the candidate.
RA Dec Sep. Match USNO/ USNO-B USNO-R USNO-V
GSC GSC-F GSC-J GSC-V
268.7250 -25.7842 19.4 -1 USNO-B1 18.58 16.22 17.27
268.7281 -25.7819 6.9 -1 USNO-B1 21.29 16.58 18.67
268.7266 -25.7805 7.6 -1 USNO-B1 17.78 15.46 16.49
268.7301 -25.7802 4.1 -1 USNO-B1 19.03 16.26 17.49 *
268.7293 -25.7793 3.1 -1 USNO-B1 15.46 13.81 14.54 *
Due to star catalog entries marked with *, this is probably NOT the afterglow
These entries are within 5.25" 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:
There are 42295.422 counts in the bkg source region of 5826.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 7.260 counts/pixel (5-sig UL in 4" is 18.38 mag) for 856977_g3381
There are 1414.9681 counts in the xrt source region of 198.00000 pixels.
Rate in xrt region with 8 arcsec radius is 7.146 counts/pixel for 856977_g3381
There are 9013.2168 counts in the xrt_bkg source region of 1224.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 7.364 counts/pixel (5-sig UL in 4" is 18.37 mag) for 856977_g3381
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 18.93, 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_557178836_180829d07h36m13s035374usUT_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(268.7174,-25.7993,45")
fk5;-circle(268.721612544694,-25.7974956704189,6")
fk5;-circle(268.714882969814,-25.808056227782,6")
fk5;-circle(268.719851678309,-25.7892712180107,6")
fk5;-circle(268.726257995607,-25.8065399189472,6")
fk5;-circle(268.724410667446,-25.7875112763139,6")
fk5;-circle(268.717232503453,-25.785700984306,6")
fk5;-circle(268.722262837724,-25.8121359793095,6")
Region file: 856977_557178836_180829d07h36m13s035374usUT_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_557178836_180829d07h36m13s035374usUT_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(268.721612544694,-25.7974956704189,6")
image paragraph message for exposure 2 of trigger 856977
WARNING -- because of the LARGE EXTINCTION, results should be used cautiously.
------ 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 26 seconds with the White filter
starting 3360 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 180829d07h36m14s404500usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=856977
-expid=557178836 -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 557178836.56018 or about 2018:240:19:53:51 UT
No information found about the number of stars in the star catalog for srclist
region.
Found 23 source(s) in Genie image catalog. Found 2 Genie image source(s)
without IDs. There are 0 good candidate(s) in the Genie image catalog. Good
candidates must be brighter than 18.93 mag. Found 281 stars in largest star
catalog for Genie image region. The stars will eliminate afterglows from about
28% of the Genie image region.
Genie image analysis:
Found 42295.4 counts in the large background region of 5826.0 pixels or a rate
of 7.260 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 18.37 mag. for a
4-arcsec aperture.
Found 1415.0 counts in the XRT position region of 198.0 pixels or a rate of
7.146 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is -1.655 +/- 1.563 (1-sigma) cps. The
3-sigma UL at the XRT position is 4.688 cps or 18.10 mag. The closest Genie
source has ra= 268.7216 dec= -25.7975 mag=16.91 sep=11.40".
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?
557178836 3359 WHITE srclist data are not available.
557178836 3359 WHITE image found no candidates.
List afterglow candidates for other finding charts.
557175600 123 ? srclist data are not available.
557175600 123 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: 19:53:51
MAGNITUDE: 18.1
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT