image overlap message for exposure 1 of trigger 821902
uvot_overlap.pl vrs. 2010-12-20b fem started at 180404d08h26m20s301976usUT
The observation of trigger 821902 started 2018-04-04T02:13:26.3
Examining file ./821902_g101_uvot_sky_image.fits
The exposure ID is 544500806
The exposure time is 149.857 (seconds)
The filter is WHITE.
The uvot region is centered at (53.3847,-50.2130) with a roll angle of 315.1
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 (53.3840,-50.1950) with a radius of 3.000 arc min
This is 1.082 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 (53.3927,-50.2155) with a radius of 0.048 arc min
This is 0.338 arc min from the center of the uvot region
The area of the XRT error circle is 0.007 sq. arc min
The UVOT/XRT overlap is 0.007 sq. arc min or 1.00 of the XRT error circle
image afterglow message for exposure 1 of trigger 821902
find_uvot_ag.pl vrs. 2017-02-17 fem started at 180404d08h26m24s228624usUT
Observation start time is 2018-04-04T02:13:26.3
Examining file ./821902_g101_uvot_catalog_image.fits
The exposure ID is 544500806
The exposure is 149.857 sec.
The bin size is 2 pixels
The filter is WHITE
There are 4 detected source(s) for 821902_g101
Aspect correction adds -0.00178 degrees (-0.427 sec of time = -4.10 arc sec) to RA
Aspect correction adds -0.00052 degrees (-1.86 arcsec) to Dec
Total aspect correction is 4.50 arcsec
Star catalogs centered at 53.3938 , -50.2170 with radius 2.46 arc min.
n_usno: 44 n_gsc: 37
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 3 matched entries is 0.193" for 821902_g101
Mean and std. dev of mag. difference (MAG_DELTA) are 0.525 and 0.788 for 821902_g101
Found 1 entries without IDs and 1 entries that are acceptable afterglow candidates for 821902_g101.
Acceptable entries have no ID, XRT distances < 7.25", 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=53.3840 (03:33:32.16) DEC=-50.1950 (-50:11:42.0)
XRT distances are from RA=53.3927 (03:33:34.24) DEC=-50.2155 (-50:12:55.8)
-----------------
Entry 0 in the list of sources is a candidate afterglow for 821902_g101 with genie
ra=53.39265 (03:33:34.24) dec=-50.21504 (-50:12:54.2) +/- 0.8" mag=18.61+/-0.15
dist=1.6 REFID=3 major=0.9 minor=0.8 flag=0
Found 1 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
53.3971 -50.2138 11.1 -1 GSC2.3 99.99 22.35 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 0 entries in star catalog(s) within 10" of the XRT position.
List UVOT sources within 10" of the XRT position:
Unmatched source ra=53.39265 (03:33:34.24) dec=-50.21504 (-50:12:54.2) +/- 0.8" mag=18.61+/-0.15 dist=1.6 REFID=3 flag=0
There are 1.0421777E+05 counts in the bkg source region of 6086.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 17.124 counts/pixel (5-sig UL in 4" is 19.81 mag) for 821902_g101
There are 1335.7047 counts in the src source region of 50.000000 pixels.
Rate in src region with 4 arcsec radius is 26.714 counts/pixel for 821902_g101
There are 21473.193 counts in the cand_src_bkg source region of 1247.0000 pixels.
Rate in cand_src_bkg region from 15 to 25 arcsec is 17.220 counts/pixel (5-sig UL in 4" is 19.80 mag) for 821902_g101
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 20.36, XRT distances < 7.25",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 1 good candidate(s) found.
Region file: 821902_544500806_180404d08h26m24s228624usUT_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(53.3847,-50.2130,45")
fk5;-circle(53.3926484660942,-50.2150420768466,6")
fk5;-circle(53.3732434381693,-50.2211163474136,6")
fk5;-circle(53.372967845845,-50.2011895999534,6")
Region file: 821902_544500806_180404d08h26m24s228624usUT_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(53.3926484660942,-50.2150420768466,4")
Region file: 821902_544500806_180404d08h26m24s228624usUT_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(53.3926484660942,-50.2150420768466,25")
fk5;-circle(53.3926484660942,-50.2150420768466,15")
image paragraph message for exposure 1 of trigger 821902
------ Start for Possible Stand-alone Circular ----
In response to GRB180404 (Swift/BAT trigger 821902) at 02:11:44 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 81 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 03:33:34.24 = 53.39265
DEC(J2000) = -50:12:54.1 = -50.21504
with a 90%-confidence error radius of about 0.76 arc sec. This position is 1.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.61 with a 1-sigma error of about 0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.01.
------- notes for trigger 821902 ------
uvot_gcn_auto.pl vrs. 2016-09-07 fem at 180404d08h26m30s904446usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=821902
-expid=544500806 -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/821902/
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 544500806.29342 or about 2018:094:02:13:21 UT
Found 208 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 5% of the srclist region. Found 27 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
19.22 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
20.36 mag. Found 40 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 4% 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?
544500806 81 WHITE 53.39267 -50.21515 18.69/19.2 1.3 srclist Yes
544500806 81 WHITE 53.39265 -50.21504 18.61/20.4 1.6 image Yes
List afterglow candidates for other finding charts.
544501019 294 U srclist found no candidates.
544501019 294 U 53.39270 -50.21482 19.64/20.2 5.6 image Yes
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: white
GRB_DEC: -50.21504
GRB_ERROR: 0.76
GRB_RA: 53.39265
IMAGE_START_TIME: 02:13:21
MAGNITUDE: 18.61
MAG_ERROR: 0.15
MESSAGE_TYPE: ACK
SOURCE: XRT