image overlap message for exposure 2 of trigger 945521
uvot_overlap.pl vrs. 2010-12-20b fem started at 191222d03h16m05s586721usUT
The observation of trigger 945521 started 2019-12-21T20:44:41.3
Examining file ./945521_g327_uvot_sky_image.fits
The exposure ID is 598653881
The exposure time is 249.935 (seconds)
The filter is U.
The uvot region is centered at (154.8338,-38.1594) with a roll angle of 123.5
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 (154.8320,-38.1410) with a radius of 3.000 arc min
This is 1.105 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 (154.8299,-38.1576) with a radius of 0.028 arc min
This is 0.212 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 945521
find_uvot_ag.pl vrs. 2017-02-17 fem started at 191222d03h16m19s804182usUT
Observation start time is 2019-12-21T20:44:41.3
Examining file ./945521_g327_uvot_catalog_image.fits
The exposure ID is 598653881
The exposure is 249.935 sec.
The bin size is 2 pixels
The filter is U
There are 16 detected source(s) for 945521_g327
Aspect correction adds 0.00125 degrees (0.300 sec of time = 3.53 arc sec) to RA
Aspect correction adds -0.00070 degrees (-2.51 arcsec) to Dec
Total aspect correction is 4.33 arcsec
Star catalogs centered at 154.8394 , -38.1599 with radius 2.75 arc min.
n_usno: 175 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 14 matched entries is 0.411" for 945521_g327
Mean and std. dev of mag. difference (MAG_DELTA) are 1.103 and 0.746 for 945521_g327
Found 2 entries without IDs and 2 entries that are acceptable afterglow candidates for 945521_g327.
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=154.8320 (10:19:19.68) DEC=-38.1410 (-38:08:27.6)
XRT distances are from RA=154.8299 (10:19:19.18) DEC=-38.1576 (-38:09:27.3)
-----------------
Entry 0 in the list of sources is a candidate afterglow for 945521_g327 with genie
ra=154.83020 (10:19:19.25) dec=-38.15765 (-38:09:27.5) +/- 0.6" mag=11.74+/-0.14
dist=0.8 REFID=6 major=1.0 minor=0.9 flag=0
Found 2 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
154.8313 -38.1604 10.4 -1 USNO-B1 16.93 16.49 16.69
154.8308 -38.1598 8.0 -1 USNO-B1 16.83 16.12 16.43
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
-----------------
Entry 13 in the list of sources is a candidate afterglow for 945521_g327 with genie
ra=154.84381 (10:19:22.52) dec=-38.13325 (-38:07:59.7) +/- 0.6" mag=17.80+/-0.15
dist=96.0 REFID=2 major=1.0 minor=0.8 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 43.6 arc sec from the BAT position.
This source is near the edge of image (0.856)
Found 1 entries in star catalog(s) within 20.0" of the candidate.
RA Dec Sep. Match USNO/ USNO-B USNO-R USNO-V
GSC GSC-F GSC-J GSC-V
154.8434 -38.1334 1.4 -1 USNO-B1 17.79 16.07 16.83 *
Due to star catalog entries marked with *, this is probably NOT the afterglow
These entries are within 5.25" or brighter than 12 mag
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
154.8308 -38.1598 8.5 -1 USNO-B1 16.83 16.12 16.43
The closest star is 8.46" away.
List UVOT sources within 10" of the XRT position:
Unmatched source ra=154.83020 (10:19:19.25) dec=-38.15765 (-38:09:27.5) +/- 0.6" mag=11.74+/-0.14 dist=0.8 REFID=6 flag=0
There are 20955.695 counts in the bkg source region of 6032.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 3.474 counts/pixel (5-sig UL in 4" is 19.79 mag) for 945521_g327
There are 20009.164 counts in the src source region of 50.000000 pixels.
Rate in src region with 4 arcsec radius is 400.183 counts/pixel for 945521_g327
There are 5935.6777 counts in the cand_src_bkg source region of 1244.0000 pixels.
Rate in cand_src_bkg region from 15 to 25 arcsec is 4.771 counts/pixel (5-sig UL in 4" is 19.62 mag) for 945521_g327
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 20.34, 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: 945521_598653881_191222d03h16m19s804182usUT_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(154.8338,-38.1594,45")
fk5;-circle(154.830200936798,-38.1576457402696,6")
fk5;-circle(154.842550615123,-38.1692738389788,6")
fk5;-circle(154.847346866964,-38.1643009065895,6")
Region file: 945521_598653881_191222d03h16m19s804182usUT_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(154.830200936798,-38.1576457402696,4")
Region file: 945521_598653881_191222d03h16m19s804182usUT_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(154.830200936798,-38.1576457402696,25")
fk5;-circle(154.830200936798,-38.1576457402696,15")
image paragraph message for exposure 2 of trigger 945521
------ Start for Possible Stand-alone Circular ----
In response to GRB191221 (Swift/BAT trigger 945521) at 20:39:13 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 250 seconds with the U filter starting
303 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 10:19:19.25 = 154.83020
DEC(J2000) = -38:09:27.5 = -38.15765
with a 90%-confidence error radius of about 0.61 arc sec. This position is 0.8
arc sec. from the center of the XRT error circle. The estimated magnitude is
11.74 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.08.
------- notes for trigger 945521 ------
uvot_gcn_auto.pl vrs. 2016-09-07 fem at 191222d03h16m23s930828usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=945521
-expid=598653881 -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/945521/
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 598653881.26466 or about 2019:355:20:44:36 UT
Found 959 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 16% of the srclist region. Found 105 sources in
srclist catalog. Found 12 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 16 source(s) in Genie image catalog. 1 source(s) are within 10.0" of the
xrt position. Found 2 Genie image source(s) without IDs. There are 1 good
candidate(s) in the Genie image catalog. Good candidates must be brighter than
20.34 mag. Found 171 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 15% 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?
598653881 303 U 154.83010 -38.15783 13.06/18.1 1.0 srclist Yes
598653881 303 U 154.83020 -38.15765 11.74/20.3 0.8 image Yes
List afterglow candidates for other finding charts.
598653668 90 WHITE 154.82986 -38.15849 15.43/19.2 3.3 srclist Yes
598653668 90 WHITE 154.82987 -38.15813 14.93/20.6 2.0 image Yes
598653668 90 WHITE 154.83092 -38.15736 15.72/20.6 2.9 image Yes
598654436 858 WHITE 154.82995 -38.15769 13.89/19.2 3.9 srclist Yes
598654436 858 WHITE 154.83018 -38.15763 13.74/20.4 4.6 image Yes
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: u
GRB_DEC: -38.15765
GRB_ERROR: 0.61
GRB_RA: 154.83020
IMAGE_START_TIME: 20:44:36
MAGNITUDE: 11.74
MAG_ERROR: 0.14
MESSAGE_TYPE: ACK
SOURCE: XRT