image overlap message for exposure 1 of trigger 1164980
uvot_overlap.pl vrs. 2010-12-20b fem started at 230420d19h40m45s493288usUT
The observation of trigger 1164980 started 2023-04-20T10:21:11.8
Examining file ./1164980_g129_uvot_sky_image.fits
The exposure ID is 703678871
The exposure time is 149.857 (seconds)
The filter is WHITE.
The uvot region is centered at (161.0421,32.1081) 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 1.946 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 6.19 sq. arc min or 0.22 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 0.309 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 1 of trigger 1164980
find_uvot_ag.pl vrs. 2023-03-28 fem started at 230420d19h40m48s206905usUT
Observation start time is 2023-04-20T10:21:11.8
Examining file ./1164980_g129_uvot_sources_image.fits
The exposure ID is 703678871
The exposure is 149.857 sec.
The bin size is 2 pixels
The filter is WHITE
There are 0 detected source(s) for 1164980_g129
*** WARNING -- Aspect solution FAILED.
Results need to be checked by, for example, blinking image with DS9.
*** WARNING -- access to usno-b1 catalog failed.
Star catalogs centered at 161.0128 , 32.0903 with radius 2.00 arc min.
n_usno: -1 n_gsc: 0
*** WARNING -- XRT position is outside star catalog search region.
*** 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
Found 0 entries without IDs and 0 entries that are acceptable afterglow candidates for 1164980_g129.
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)
Found 0 entries in star catalog(s) within 20" of the XRT position.
List UVOT sources within 20" of the XRT position:
There are 51585.906 counts in the bkg source region of 6319.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 8.164 counts/pixel (5-sig UL in 4" is 20.21 mag) for 1164980_g129
There are 1626.5813 counts in the xrt source region of 198.00000 pixels.
Rate in xrt region with 8 arcsec radius is 8.215 counts/pixel for 1164980_g129
There are 10102.142 counts in the xrt_bkg source region of 1247.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 8.101 counts/pixel (5-sig UL in 4" is 20.21 mag) for 1164980_g129
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.
Results are questionable because aspect solution FAILED.
Region file: 1164980_703678871_230420d19h40m48s206905usUT_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(161.0421,32.1081,45")
Region file: 1164980_703678871_230420d19h40m48s206905usUT_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_703678871_230420d19h40m48s206905usUT_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 1 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 99 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 230420d19h40m52s584497usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1164980
-expid=703678871 -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 703678871.75424 or about 2023:110:10:21:06 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 15 sources in srclist catalog. Found 3 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 0 source(s) in Genie image catalog. 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 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. The XRT position was
OUTSIDE the star catalog search region.
Genie image analysis:
Found 51585.9 counts in the large background region of 6319.0 pixels or a rate
of 8.164 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 20.04 mag. for a
4-arcsec aperture.
Found 1626.6 counts in the XRT position region of 198.0 pixels or a rate of
8.215 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is 0.151 +/- 0.289 (1-sigma) cps or
21.66 mag and a range from 20.50 to 99.99 mag. The 3-sigma UL at the XRT
position is 1.018 cps or 19.59 mag. The closest srclist source has ra= 161.0682
dec= 32.0923 mag=15.37 sep=82.32".
This paragraph is only useful if the XRT position is grossly wrong. There are 1
candidate(s) in the srclist data with mag < 18.66 inside the BAT error region,
but outside the XRT error region. The brightest such source is at RA=161.06861
(10:44:16.47), DEC=32.09183 (+32:05:30.6) (J2000). It has a mag of 17.48. It is
170.5" from the BAT position.
****THIS SOURCE IS OUTSIDE XRT ERROR CIRCLE--USE WITH CAUTION***
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 99 seconds after the BAT trigger. There is a candidate afterglow in
the list of sources generated on-board at
RA(J2000) = 10:44:16.47 = 161.06861
DEC(J2000) = +32:05:30.6 = 32.09183
with a 90%-confidence error radius of about 1.10 arc sec. The estimated
magnitude is 17.48 with a 1-sigma error of about 0.35. No correction has been
made for the expected extinction corresponding to E(B-V) of 0.017.
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?
703678871 98 WHITE srclist found no candidates.
703678871 98 WHITE image found no candidates.
List afterglow candidates for other finding charts.
703679030 257 U srclist found no candidates.
703679030 257 U image found no candidates.
703679635 862 WHITE srclist found no candidates.
703679635 862 WHITE 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: 10:21:06
MAGNITUDE: 19.6
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT