image overlap message for exposure 3 of trigger 1164980
uvot_overlap.pl vrs. 2010-12-20b fem started at 230420d19h40m46s571229usUT
The observation of trigger 1164980 started 2023-04-20T10:33:55.8
Examining file ./1164980_g893_uvot_sky_image.fits
The exposure ID is 703679635
The exposure time is 149.857 (seconds)
The filter is WHITE.
The uvot region is centered at (161.0441,32.1095) with a roll angle of 306.2
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 (161.0130,32.0870) with a radius of 3.000 arc min
This is 2.079 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 5.82 sq. arc min or 0.21 of the BAT error circle
The XRT error circle is centered at (161.0482,32.1077) with a radius of 0.037 arc min
This is 0.231 arc min from the center of the uvot region
The area of the XRT error circle is 0.004 sq. arc min
The UVOT/XRT overlap is 0.004 sq. arc min or 1.00 of the XRT error circle
image afterglow message for exposure 3 of trigger 1164980
find_uvot_ag.pl vrs. 2023-03-28 fem started at 230420d19h41m04s030086usUT
Observation start time is 2023-04-20T10:33:55.8
Examining file ./1164980_g893_uvot_catalog_image.fits
The exposure ID is 703679635
The exposure is 149.857 sec.
The bin size is 2 pixels
The filter is WHITE
There are 1 detected source(s) for 1164980_g893
Aspect correction adds -0.00188 degrees (-0.451 sec of time = -5.73 arc sec) to RA
Aspect correction adds 0.00108 degrees ( 3.88 arcsec) to Dec
Total aspect correction is 6.92 arcsec
*** WARNING -- access to usno-b1 catalog failed.
Star catalogs centered at 161.0685 , 32.0946 with radius 2.00 arc min.
n_usno: -1 n_gsc: 0
*** WARNING -- no star catalog entries found.
-- this strongly suggests a problem with the catalogs.
-- cannot check for bright stars or nearby sources.
-- there is a high risk of false positives.
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 0 matched entries is 0.000" for 1164980_g893
Mean and std. dev of mag. difference (MAG_DELTA) are 0.000 and -1.000 for 1164980_g893
Found 1 entries without IDs and 1 entries that are acceptable afterglow candidates for 1164980_g893.
Acceptable entries have no ID, XRT distances < 5.5", 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=161.0130 (10:44:03.12) DEC=32.0870 (+32:05:13.2)
XRT distances are from RA=161.0482 (10:44:11.56) DEC=32.1077 (+32:06:27.7)
*** WARNING 100 per cent of entries have no IDs.
-----------------
Entry 0 in the list of sources is a candidate afterglow for 1164980_g893 with genie
ra=161.06887 (10:44:16.53) dec=32.09686 (+32:05:48.7) +/- 0.9" mag=20.28+/-0.20
dist=74.2 REFID=1 major=2.6 minor=1.9 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 174.1 arc sec from the BAT position.
This source is near the edge of image (0.921)
Found 0 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)
*** If XRT position is correct, then this is NOT the afterglow
*** unacceptable major profile of 2.6
Found 0 entries in star catalog(s) within 10" of the XRT position.
List UVOT sources within 10" of the XRT position:
There are 51717.562 counts in the bkg source region of 6309.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 8.197 counts/pixel (5-sig UL in 4" is 20.21 mag) for 1164980_g893
There are 1672.8619 counts in the xrt source region of 199.00000 pixels.
Rate in xrt region with 8 arcsec radius is 8.406 counts/pixel for 1164980_g893
There are 9980.3232 counts in the xrt_bkg source region of 1247.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 8.003 counts/pixel (5-sig UL in 4" is 20.22 mag) for 1164980_g893
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 20.76, XRT distances < 5.5",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 0 good candidate(s) found.
Region file: 1164980_703679635_230420d19h41m04s030086usUT_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(161.0441,32.1095,45")
Region file: 1164980_703679635_230420d19h41m04s030086usUT_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(161.04817,32.10769,8")
Region file: 1164980_703679635_230420d19h41m04s030086usUT_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(161.04817,32.10769,25")
fk5;-circle(161.04817,32.10769,15")
image paragraph message for exposure 3 of trigger 1164980
------ Start for Possible Stand-alone Circular ----
In response to GRB230420 (Swift/BAT trigger 1164980) at 10:19:01 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 863 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.
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.017.
------- notes for trigger 1164980 ------
uvot_gcn_auto.pl vrs. 2023-03-28 fem at 230420d19h41m08s432930usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1164980
-expid=703679635 -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/1164980/
Links to data for all triggers can be found at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/
XRT position found for srclist. XRT position found for Genie image. BAT
position found.
UVOT exposure began at MET 703679635.77282 or about 2023:110:10:33:50 UT
Access to USNO star catalog FAILED. This increases the odds of a FALSE
afterglow detection. There was likely a PROBLEM with the srclist star catalog
because no stars found. Found 27 sources in srclist catalog. Found 6 srclist
source(s) without IDs. There are 0 good candidate(s) in the srclist catalog.
Good candidates must be brighter than 19.22 mag.
Access to USNO star catalog FAILED. This increases the odds of a FALSE
afterglow detection. Found 1 source(s) in Genie image catalog. 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 20.76 mag. Found 0 stars in
largest star catalog for Genie image region. The stars will eliminate
afterglows from about 0% of the Genie image region.
Genie image analysis:
Found 51717.6 counts in the large background region of 6309.0 pixels or a rate
of 8.197 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 20.03 mag. for a
4-arcsec aperture.
Found 1672.9 counts in the XRT position region of 199.0 pixels or a rate of
8.407 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is 0.535 +/- 0.293 (1-sigma) cps or
20.28 mag and a range from 19.81 to 21.14 mag. The 3-sigma UL at the XRT
position is 1.413 cps or 19.23 mag. The closest srclist source has ra= 161.0681
dec= 32.0922 mag=16.01 sep=82.52". The closest Genie source has ra= 161.0689
dec= 32.0969 mag=20.28 sep=74.21".
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?
703679635 862 WHITE srclist found no candidates.
703679635 862 WHITE image found no candidates.
List afterglow candidates for other finding charts.
703678871 98 WHITE srclist found no candidates.
703678871 98 WHITE image found no candidates.
703679030 257 U srclist found no candidates.
703679030 257 U image found no candidates.
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: white
GRB_DEC: 32.10769
GRB_ERROR: 5.5
GRB_RA: 161.04817
IMAGE_START_TIME: 10:33:50
MAGNITUDE: 19.2
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT