image overlap message for exposure 3 of trigger 1121751
uvot_overlap.pl vrs. 2010-12-20b fem started at 220826d14h57m05s257791usUT
The observation of trigger 1121751 started 2022-08-26T12:10:11.4
Examining file ./1121751_g889_uvot_sky_image.fits
The exposure ID is 683208611
The exposure time is 12.608 (seconds)
The filter is WHITE.
The uvot region is centered at (206.4031,-44.0384) with a roll angle of 305.9
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 (206.4310,-44.0440) with a radius of 3.000 arc min
This is 1.249 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 7.15 sq. arc min or 0.25 of the BAT error circle
The XRT error circle is centered at (206.4108,-44.0392) with a radius of 0.037 arc min
This is 0.334 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 1121751
find_uvot_ag.pl vrs. 2020-10-30 fem started at 220826d14h57m27s265412usUT
Observation start time is 2022-08-26T12:10:11.4
Examining file ./1121751_g889_uvot_catalog_image.fits
The exposure ID is 683208611
The exposure is 12.608 sec.
The bin size is 2 pixels
The filter is WHITE
There are 17 detected source(s) for 1121751_g889
Aspect correction adds -0.00292 degrees (-0.702 sec of time = -7.57 arc sec) to RA
Aspect correction adds 0.00047 degrees ( 1.68 arcsec) to Dec
Total aspect correction is 7.75 arcsec
Star catalogs centered at 206.4024 , -44.0400 with radius 2.52 arc min.
n_usno: 210 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 17 matched entries is 0.479" for 1121751_g889
Mean and std. dev of mag. difference (MAG_DELTA) are 1.105 and 0.477 for 1121751_g889
Found 0 entries without IDs and 0 entries that are acceptable afterglow candidates for 1121751_g889.
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=206.4310 (13:45:43.44) DEC=-44.0440 (-44:02:38.4)
XRT distances are from RA=206.4108 (13:45:38.59) DEC=-44.0392 (-44:02:21.0)
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
206.4113 -44.0370 8.0 -1 USNO-B1 19.77 19.11 19.40
206.4139 -44.0402 8.9 -1 USNO-B1 18.68 18.33 18.49
The closest star is 8.03" away.
List UVOT sources within 10" of the XRT position:
Matched source ra=206.41399 (13:45:39.36) dec=-44.04029 (-44:02:25.0) +/- 1.1" mag=19.42+/-0.33 dist=9.2 REFID=10 flag=0
There are 6099.8472 counts in the bkg source region of 5882.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 1.037 counts/pixel (5-sig UL in 4" is 18.64 mag) for 1121751_g889
There are 216.22081 counts in the xrt source region of 199.00000 pixels.
Rate in xrt region with 8 arcsec radius is 1.087 counts/pixel for 1121751_g889
There are 1146.9307 counts in the xrt_bkg source region of 1146.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 1.001 counts/pixel (5-sig UL in 4" is 18.66 mag) for 1121751_g889
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 19.20, 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: 1121751_683208611_220826d14h57m27s265412usUT_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(206.4031,-44.0384,45")
fk5;-circle(206.413988542776,-44.0402910639597,6")
fk5;-circle(206.419922953427,-44.0398102316991,6")
fk5;-circle(206.410345769569,-44.0492682943626,6")
fk5;-circle(206.400500313808,-44.0378278349026,6")
fk5;-circle(206.398463507602,-44.052073198868,6")
fk5;-circle(206.400945616048,-44.0252983792747,6")
fk5;-circle(206.38534274164,-44.0348970124188,6")
Region file: 1121751_683208611_220826d14h57m27s265412usUT_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(206.41079,-44.03917,8")
Region file: 1121751_683208611_220826d14h57m27s265412usUT_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(206.41079,-44.03917,25")
fk5;-circle(206.41079,-44.03917,15")
fk5;-circle(206.413988542776,-44.0402910639597,6")
fk5;-circle(206.419922953427,-44.0398102316991,6")
fk5;-circle(206.400500313808,-44.0378278349026,6")
image paragraph message for exposure 3 of trigger 1121751
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 GRB220826 (Swift/BAT trigger 1121751) at 11:55:21 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 13 seconds with the White filter
starting 859 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 expected extinction corresponding to
E(B-V) of 0.110.
------- notes for trigger 1121751 ------
uvot_gcn_auto.pl vrs. 2020-10-27 fem at 220826d14h57m32s522883usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1121751
-expid=683208611 -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/1121751/
Links to data for all triggers can be found at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/
XRT position found for Genie image. BAT position found.
UVOT exposure began at MET 683208611.36184 or about 2022:238:12:10:06 UT
No information found about the number of stars in the star catalog for srclist
region.
Found 17 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
19.20 mag. Found 206 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 22% of the Genie image region.
Genie image analysis:
Found 6099.8 counts in the large background region of 5882.0 pixels or a rate
of 1.037 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 18.50 mag. for a
4-arcsec aperture.
Found 216.2 counts in the XRT position region of 199.0 pixels or a rate of
1.086 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is 1.311 +/- 1.218 (1-sigma) cps or
19.31 mag and a range from 18.60 to 22.18 mag. The 3-sigma UL at the XRT
position is 4.966 cps or 17.86 mag.
Found 1 Genie source(s) within 10.0" of the XRT position. The brightest such
source has ra= 206.4140 dec= -44.0403 mag=19.42 sep=9.21". The closest Genie
source has ra= 206.4140 dec= -44.0403 mag=19.42 sep=9.21".
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 13 seconds with the White filter
starting 859 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 13:45:39.36 = 206.41399
DEC(J2000) = -44:02:25.0 = -44.04029
with a 90%-confidence error radius of about 1.09 arc sec. This position is 9.21
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.42 with a 1-sigma error of about 0.33. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.110.
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?
683208611 859 WHITE srclist data are not available.
683208611 859 WHITE image found no candidates.
List afterglow candidates for other finding charts.
683207842 90 WHITE 206.41045 -44.03867 18.73/19.2 2.0 srclist Yes
683207842 90 WHITE 206.41049 -44.03862 17.89/20.3 2.1 image Yes
683208054 302 U srclist found no candidates.
683208054 302 U 206.41043 -44.03878 18.67/20.1 1.7 image Yes
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: white
GRB_DEC: -44.03917
GRB_ERROR: 5.5
GRB_RA: 206.41079
IMAGE_START_TIME: 12:10:06
MAGNITUDE: 17.9
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT