image overlap message for exposure 2 of trigger 842475
uvot_overlap.pl vrs. 2010-12-20b fem started at 180618d03h28m38s688599usUT
The observation of trigger 842475 started 2018-06-18T00:48:32.0
Examining file ./842475_g319_uvot_sky_image.fits
The exposure ID is 550975712
The exposure time is 249.946 (seconds)
The filter is U.
The uvot region is centered at (169.9283,73.8356) with a roll angle of 270.5
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 (169.9370,73.8480) with a radius of 3.000 arc min
This is 0.761 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 (169.9414,73.8373) with a radius of 0.028 arc min
This is 0.243 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 842475
find_uvot_ag.pl vrs. 2017-02-17 fem started at 180618d03h28m47s541056usUT
Observation start time is 2018-06-18T00:48:32.0
Examining file ./842475_g319_uvot_catalog_image.fits
The exposure ID is 550975712
The exposure is 249.946 sec.
The bin size is 2 pixels
The filter is U
There are 4 detected source(s) for 842475_g319
Aspect correction adds -0.00018 degrees (-0.042 sec of time = -0.18 arc sec) to RA
Aspect correction adds 0.00034 degrees ( 1.22 arcsec) to Dec
Total aspect correction is 1.23 arcsec
Star catalogs centered at 169.9450 , 73.8372 with radius 2.28 arc min.
n_usno: 32 n_gsc: 27
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 3 matched entries is 0.446" for 842475_g319
Mean and std. dev of mag. difference (MAG_DELTA) are 2.247 and 1.124 for 842475_g319
Found 1 entries without IDs and 1 entries that are acceptable afterglow candidates for 842475_g319.
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=169.9370 (11:19:44.88) DEC=73.8480 (+73:50:52.8)
XRT distances are from RA=169.9414 (11:19:45.94) DEC=73.8373 (+73:50:14.3)
-----------------
Entry 0 in the list of sources is a candidate afterglow for 842475_g319 with genie
ra=169.94103 (11:19:45.85) dec=73.83700 (+73:50:13.2) +/- 0.8" mag=17.39+/-0.15
dist=1.2 REFID=4 major=1.1 minor=0.9 flag=0
Found 3 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)
RA Dec Sep. Match USNO/ USNO-B USNO-R USNO-V
GSC GSC-F GSC-J GSC-V
169.9339 73.8383 8.5 -1 USNO-B1 21.52 19.59 20.45
169.9301 73.8381 11.7 -1 USNO-B1 20.66 99.99 99.99
169.9342 73.8382 8.2 -1 GSC2.3 99.99 21.43 99.99
uvot_check_outside found 13 of 13 good pixels
##### This source remains a candidate #####
It has no entries within 3.5" or brighter than 12 mag
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
169.9339 73.8383 8.3 -1 USNO-B1 21.52 19.59 20.45
169.9342 73.8382 8.0 -1 GSC2.3 99.99 21.43 99.99
The closest star is 7.98" away.
List UVOT sources within 10" of the XRT position:
Unmatched source ra=169.94103 (11:19:45.85) dec=73.83700 (+73:50:13.2) +/- 0.8" mag=17.39+/-0.15 dist=1.2 REFID=4 flag=0
There are 14590.630 counts in the bkg source region of 6175.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 2.363 counts/pixel (5-sig UL in 4" is 20.00 mag) for 842475_g319
There are 584.84863 counts in the src source region of 51.000000 pixels.
Rate in src region with 4 arcsec radius is 11.468 counts/pixel for 842475_g319
There are 2952.6392 counts in the cand_src_bkg source region of 1248.0000 pixels.
Rate in cand_src_bkg region from 15 to 25 arcsec is 2.366 counts/pixel (5-sig UL in 4" is 20.00 mag) for 842475_g319
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 20.55, XRT distances < 5",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 1 good candidate(s) found.
Region file: 842475_550975712_180618d03h28m47s541056usUT_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(169.9283,73.8356,45")
fk5;-circle(169.941030718806,73.8370029243527,6")
fk5;-circle(169.889382485567,73.8434126602717,6")
Region file: 842475_550975712_180618d03h28m47s541056usUT_cand_src.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(169.941030718806,73.8370029243527,4")
Region file: 842475_550975712_180618d03h28m47s541056usUT_cand_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(169.941030718806,73.8370029243527,25")
fk5;-circle(169.941030718806,73.8370029243527,15")
image paragraph message for exposure 2 of trigger 842475
------ Start for Possible Stand-alone Circular ----
In response to GRB180618 (Swift/BAT trigger 842475) at 00:43:12 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 250 seconds with the U filter starting
297 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 11:19:45.85 = 169.94103
DEC(J2000) = +73:50:13.2 = 73.83700
with a 90%-confidence error radius of about 0.76 arc sec. This position is 1.2
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.39 with a 1-sigma error of about 0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.07.
------- notes for trigger 842475 ------
uvot_gcn_auto.pl vrs. 2016-09-07 fem at 180618d03h28m50s737201usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=842475
-expid=550975712 -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/842475/
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 550975712.04414 or about 2018:169:00:48:27 UT
Found 130 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 3% of the srclist region. Found 11 sources in
srclist catalog. Found 2 srclist source(s) without IDs. There are 1 good
candidate(s) in the srclist catalog. Good candidates must be brighter than
18.12 mag.
Found 4 source(s) in Genie image catalog. 1 source(s) are within 10.0" of the
xrt position. Found 1 Genie image source(s) without IDs. There are 1 good
candidate(s) in the Genie image catalog. Good candidates must be brighter than
20.55 mag. Found 28 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 3% of the Genie image region.
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?
550975712 297 U 169.94069 73.83696 17.89/18.1 1.5 srclist Yes
550975712 297 U 169.94103 73.83700 17.39/20.6 1.2 image Yes
List afterglow candidates for other finding charts.
550975500 85 WHITE 169.94074 73.83704 17.81/19.2 1.2 srclist Yes
550975500 85 WHITE image found no candidates.
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: u
GRB_DEC: 73.83700
GRB_ERROR: 0.76
GRB_RA: 169.94103
IMAGE_START_TIME: 00:48:27
MAGNITUDE: 17.39
MAG_ERROR: 0.15
MESSAGE_TYPE: ACK
SOURCE: XRT