image overlap message for exposure 2 of trigger 997453
uvot_overlap.pl vrs. 2010-12-20b fem started at 200926d04h11m06s120333usUT
The observation of trigger 997453 started 2020-09-25T21:55:56.6
Examining file ./997453_g318_uvot_sky_image.fits
The exposure ID is 622763756
The exposure time is 249.935 (seconds)
The filter is U.
The uvot region is centered at (246.8309,78.3915) with a roll angle of 244.0
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 (246.8510,78.3940) with a radius of 3.000 arc min
This is 0.287 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 (246.7852,78.3905) with a radius of 0.030 arc min
This is 0.554 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 997453
find_uvot_ag.pl vrs. 2017-02-17 fem started at 200926d04h11m43s991059usUT
Observation start time is 2020-09-25T21:55:56.6
Examining file ./997453_g318_uvot_catalog_image.fits
The exposure ID is 622763756
The exposure is 249.935 sec.
The bin size is 2 pixels
The filter is U
There are 5 detected source(s) for 997453_g318
Aspect correction adds -0.00959 degrees (-2.301 sec of time = -6.95 arc sec) to RA
Aspect correction adds -0.00032 degrees (-1.16 arcsec) to Dec
Total aspect correction is 7.04 arcsec
Star catalogs centered at 246.8537 , 78.3946 with radius 2.11 arc min.
n_usno: 35 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 5 matched entries is 0.238" for 997453_g318
Mean and std. dev of mag. difference (MAG_DELTA) are 1.092 and 0.299 for 997453_g318
Found 0 entries without IDs and 0 entries that are acceptable afterglow candidates for 997453_g318.
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=246.8510 (16:27:24.24) DEC=78.3940 (+78:23:38.4)
XRT distances are from RA=246.7852 (16:27:08.45) DEC=78.3905 (+78:23:25.9)
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
246.7954 78.3907 7.4 -1 USNO-B1 16.98 15.36 16.08
246.7951 78.3900 7.4 -1 USNO-B1 99.99 19.05 99.99
The closest star is 7.38" away.
List UVOT sources within 10" of the XRT position:
Matched source ra=246.79538 (16:27:10.89) dec=78.39074 (+78:23:26.7) +/- 0.6" mag=16.93+/-0.15 dist=7.4 REFID=4 flag=0
There are 54680.852 counts in the bkg source region of 6094.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 8.973 counts/pixel (5-sig UL in 4" is 19.27 mag) for 997453_g318
There are 2171.5774 counts in the xrt source region of 200.00000 pixels.
Rate in xrt region with 8 arcsec radius is 10.858 counts/pixel for 997453_g318
There are 11271.586 counts in the xrt_bkg source region of 1246.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 9.046 counts/pixel (5-sig UL in 4" is 19.27 mag) for 997453_g318
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 19.83, 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: 997453_622763756_200926d04h11m43s991059usUT_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(246.8309,78.3915,45")
fk5;-circle(246.831643207067,78.4027595885472,6")
fk5;-circle(246.795380319203,78.3907397828686,6")
Region file: 997453_622763756_200926d04h11m43s991059usUT_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(246.78521,78.39053,8")
Region file: 997453_622763756_200926d04h11m43s991059usUT_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(246.78521,78.39053,25")
fk5;-circle(246.78521,78.39053,15")
image paragraph message for exposure 2 of trigger 997453
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 GRB200925 (Swift/BAT trigger 997453) at 21:50:37 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 250 seconds with the U filter starting
293 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 19.2 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 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.04.
------- notes for trigger 997453 ------
uvot_gcn_auto.pl vrs. 2016-09-07 fem at 200926d04h11m48s821337usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=997453
-expid=622763756 -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/997453/
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 622763756.62044 or about 2020:269:21:55:51 UT
Found 506 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 5% of the srclist region. Found 48 sources in
srclist catalog. Found 8 srclist source(s) without IDs. There are 0 good
candidate(s) in the srclist catalog. Good candidates must be brighter than
18.12 mag.
Found 5 source(s) in Genie image catalog. 1 source(s) are within 10.0" of the
xrt position. Found 0 Genie image source(s) without IDs. There are 0 good
candidate(s) in the Genie image catalog. Good candidates must be brighter than
19.83 mag. Found 31 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 4% of the Genie image region.
Genie image analysis:
Found 54680.9 counts in the large background region of 6094.0 pixels or a rate
of 8.973 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 19.31 mag. for a
4-arcsec aperture.
Found 2171.6 counts in the XRT position region of 200.0 pixels or a rate of
10.858 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is 1.449 +/- 0.198 (1-sigma) cps or
17.98 mag and a range from 17.84 to 18.14 mag. The 3-sigma UL at the XRT
position is 2.045 cps or 17.60 mag.
Found 1 srclist source(s) within 10.0" of the XRT position.
The brightest such source has ra= 246.7961 dec= 78.3909 mag=17.52 sep=8.01".
The closest srclist source has ra= 246.7961 dec= 78.3909 mag=17.52 sep=8.01".
Found 1 Genie source(s) within 10.0" of the XRT position. The brightest such
source has ra= 246.7954 dec= 78.3907 mag=16.93 sep=7.41". The closest Genie
source has ra= 246.7954 dec= 78.3907 mag=16.93 sep=7.41".
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 250 seconds with the U filter starting
293 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 16:27:10.89 = 246.79538
DEC(J2000) = +78:23:26.7 = 78.39074
with a 90%-confidence error radius of about 0.62 arc sec. This position is 7.41
arc sec. from the center of the XRT error circle. The estimated magnitude is
16.93 with a 1-sigma error of about 0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.04.
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?
622763756 293 U srclist found no candidates.
622763756 293 U image found no candidates.
List afterglow candidates for other finding charts.
622763544 81 WHITE srclist found no candidates.
622763544 81 WHITE image found no candidates.
622764334 871 WHITE srclist found no candidates.
622764334 871 WHITE image found no candidates.
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: u
GRB_DEC: 78.39053
GRB_ERROR: 5
GRB_RA: 246.78521
IMAGE_START_TIME: 21:55:51
MAGNITUDE: 17.6
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT