image overlap message for exposure 1 of trigger 854578
uvot_overlap.pl vrs. 2010-12-20b fem started at 180821d22h56m36s511172usUT
The observation of trigger 854578 started 2018-08-21T16:44:34.7
Examining file ./854578_g239_uvot_sky_image.fits
The exposure ID is 556562674
The exposure time is 149.868 (seconds)
The filter is WHITE.
The uvot region is centered at (7.7937,-38.6290) with a roll angle of 118.9
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 (7.7630,-38.6190) with a radius of 3.000 arc min
This is 1.558 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 6.95 sq. arc min or 0.25 of the BAT error circle
The XRT error circle is centered at (7.7901,-38.6271) with a radius of 0.028 arc min
This is 0.201 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 1 of trigger 854578
find_uvot_ag.pl vrs. 2017-02-17 fem started at 180821d22h56m48s946733usUT
Observation start time is 2018-08-21T16:44:34.7
Examining file ./854578_g239_uvot_catalog_image.fits
The exposure ID is 556562674
The exposure is 149.868 sec.
The bin size is 2 pixels
The filter is WHITE
There are 1 detected source(s) for 854578_g239
Aspect correction adds 0.00045 degrees (0.109 sec of time = 1.28 arc sec) to RA
Aspect correction adds -0.00120 degrees (-4.33 arcsec) to Dec
Total aspect correction is 4.51 arcsec
Star catalogs centered at 7.8049 , -38.6331 with radius 2.00 arc min.
n_usno: 28 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 1 matched entries is 1.301" for 854578_g239
Mean and std. dev of mag. difference (MAG_DELTA) are 1.064 and 0.000 for 854578_g239
Found 0 entries without IDs and 0 entries that are acceptable afterglow candidates for 854578_g239.
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= 7.7630 (00:31:03.12) DEC=-38.6190 (-38:37:08.4)
XRT distances are from RA= 7.7901 (00:31:09.63) DEC=-38.6271 (-38:37:37.7)
Found 1 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
7.7876 -38.6277 7.3 -1 USNO-B1 20.37 20.27 20.31
The closest star is 7.30" away.
List UVOT sources within 10" of the XRT position:
There are 47090.098 counts in the bkg source region of 6319.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 7.452 counts/pixel (5-sig UL in 4" is 20.26 mag) for 854578_g239
There are 1508.6666 counts in the xrt source region of 201.00000 pixels.
Rate in xrt region with 8 arcsec radius is 7.506 counts/pixel for 854578_g239
There are 9336.1025 counts in the xrt_bkg source region of 1250.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 7.469 counts/pixel (5-sig UL in 4" is 20.26 mag) for 854578_g239
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 20.81, 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: 854578_556562674_180821d22h56m48s946733usUT_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(7.7937,-38.6290,45")
Region file: 854578_556562674_180821d22h56m48s946733usUT_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(7.79013,-38.62714,8")
Region file: 854578_556562674_180821d22h56m48s946733usUT_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(7.79013,-38.62714,25")
fk5;-circle(7.79013,-38.62714,15")
image paragraph message for exposure 1 of trigger 854578
------ Start for Possible Stand-alone Circular ----
In response to GRB180821 (Swift/BAT trigger 854578) at 16:40:34 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 218 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
0.02.
------- notes for trigger 854578 ------
uvot_gcn_auto.pl vrs. 2016-09-07 fem at 180821d22h56m51s169427usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=854578
-expid=556562674 -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/854578/
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 556562674.6742 or about 2018:233:16:44:29 UT
Found 221 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 4% of the srclist region. Found 22 sources in
srclist catalog. Found 7 srclist source(s) without IDs. There are 0 good
candidate(s) in the srclist catalog. Good candidates must be brighter than
19.22 mag.
Found 1 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 20.81 mag. Found 24 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 47090.1 counts in the large background region of 6319.0 pixels or a rate
of 7.452 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 20.26 mag. for a
4-arcsec aperture.
Found 1508.7 counts in the XRT position region of 201.0 pixels or a rate of
7.506 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is 0.050 +/- 0.279 (1-sigma) cps or
23.04 mag and a range from 20.99 to 99.99 mag. The 3-sigma UL at the XRT
position is 0.886 cps or 19.91 mag. The closest srclist source has ra= 7.7471
dec= -38.6292 mag=17.73 sep=121.33". The closest Genie source has ra= 7.8143
dec= -38.6367 mag=19.66 sep=76.12".
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?
556562674 218 WHITE srclist found no candidates.
556562674 218 WHITE image found no candidates.
List afterglow candidates for other finding charts.
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: white
GRB_DEC: -38.62714
GRB_ERROR: 5
GRB_RA: 7.79013
IMAGE_START_TIME: 16:44:29
MAGNITUDE: 19.9
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT