image overlap message for exposure 3 of trigger 945521


uvot_overlap.pl vrs. 2010-12-20b fem started at 191222d03h16m06s399510usUT

The observation of trigger 945521 started 2019-12-21T20:53:56.6
Examining file ./945521_g882_uvot_sky_image.fits
The exposure ID is 598654436
The exposure time is 149.846 (seconds)
The filter is WHITE.

The uvot region is centered at (154.8345,-38.1600) 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 1.143 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 0.258 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 3 of trigger 945521


find_uvot_ag.pl vrs. 2017-02-17 fem started at 191222d03h16m29s366872usUT

Observation start time is 2019-12-21T20:53:56.6
Examining file ./945521_g882_uvot_catalog_image.fits
The exposure ID is 598654436
The exposure is 149.846 sec.
The bin size is 2 pixels
The filter is WHITE
There are 22 detected source(s) for 945521_g882
Aspect correction adds 0.00100 degrees (0.240 sec of time = 2.84 arc sec) to RA
Aspect correction adds -0.00070 degrees (-2.52 arcsec) to Dec
Total aspect correction is 3.79 arcsec
Star catalogs centered at 154.8397 , -38.1599 with radius 2.76 arc min.
n_usno: 174 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 20 matched entries is 0.421" for 945521_g882
Mean and std. dev of mag. difference (MAG_DELTA) are 0.802 and 0.538 for 945521_g882
Found 2 entries without IDs and 2 entries that are acceptable afterglow candidates for 945521_g882.
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_g882 with genie
 ra=154.83018 (10:19:19.24) dec=-38.15763 (-38:09:27.5) +/- 0.6" mag=13.74+/-0.14
 dist=0.8 REFID=12 major=1.0 minor=0.7 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 
  154.8313 -38.1604  10.5    -1 USNO-B1  16.93  16.49  16.69
  154.8308 -38.1598   8.1    -1 USNO-B1  16.83  16.12  16.43
  154.8275 -38.1525  19.9    -1 USNO-B1  19.40  17.63  18.42
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 18 in the list of sources is a candidate afterglow for 945521_g882 with genie
 ra=154.84381 (10:19:22.51) dec=-38.13325 (-38:07:59.7) +/- 0.6" mag=17.46+/-0.14
 dist=96.0 REFID=2 major=1.0 minor=0.9 flag=16 (aperture_incomplete)
*** The position of this source is inconsistent with the XRT position.
    The position is 43.5 arc sec from the BAT position.
This source is near the edge of image (0.891)
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=154.83018 (10:19:19.24) dec=-38.15763 (-38:09:27.5) +/- 0.6" mag=13.74+/-0.14 dist=0.8 REFID=12 flag=0
There are 84910.164 counts in the bkg source region of 5535.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 15.341 counts/pixel (5-sig UL in 4" is 19.87 mag) for 945521_g882
There are 12784.590 counts in the src source region of 50.000000 pixels.
Rate in src region with 4 arcsec radius is 255.692 counts/pixel for 945521_g882
There are 17280.178 counts in the cand_src_bkg source region of 1038.0000 pixels.
Rate in cand_src_bkg region from 15 to 25 arcsec is 16.648 counts/pixel (5-sig UL in 4" is 19.82 mag) for 945521_g882

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 20.42, 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_598654436_191222d03h16m29s366872usUT_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(154.8345,-38.1600,45")
fk5;-circle(154.830179280995,-38.1576306759004,6")
fk5;-circle(154.831403664595,-38.1606547325534,6")
fk5;-circle(154.824752808095,-38.1535715971955,6")
fk5;-circle(154.827742762359,-38.1525268212045,6")
fk5;-circle(154.837281672554,-38.1686946567848,6")
fk5;-circle(154.842579695224,-38.1693171018625,6")
fk5;-circle(154.847478615115,-38.1643172321019,6")
fk5;-circle(154.849488285154,-38.1666923336376,6")



Region file: 945521_598654436_191222d03h16m29s366872usUT_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(154.830179280995,-38.1576306759004,4")



Region file: 945521_598654436_191222d03h16m29s366872usUT_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(154.830179280995,-38.1576306759004,25")
fk5;-circle(154.830179280995,-38.1576306759004,15")
fk5;-circle(154.831403664595,-38.1606547325534,6")
fk5;-circle(154.824752808095,-38.1535715971955,6")
fk5;-circle(154.827742762359,-38.1525268212045,6")



image paragraph message for exposure 3 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 150 seconds with the White filter
starting 859 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 10:19:19.24 = 154.83018
DEC(J2000) = -38:09:27.5 = -38.15763
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
13.74 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 191222d03h16m33s271953usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=945521
-expid=598654436 -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 598654436.57348 or about 2019:355:20:53:51 UT

Found 1840 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 16% of the srclist region. Found 190 sources in
srclist catalog. WARNING -- srclist catalog buffer filled. Found 8 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 22 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
20.42 mag. Found 170 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?
598654436  858 WHITE 154.82995	-38.15769  13.89/19.2	 0.4  srclist  Yes
598654436  858 WHITE 154.83018	-38.15763  13.74/20.4	 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
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

------- Tokens for Quick GCN -------

CATALOG_TYPE: IMAGE
FILTER: white
GRB_DEC: -38.15763
GRB_ERROR: 0.61
GRB_RA: 154.83018
IMAGE_START_TIME: 20:53:51
MAGNITUDE: 13.74
MAG_ERROR: 0.14
MESSAGE_TYPE: ACK
SOURCE: XRT