From: Robert A. Knop Jr. (robert.a.knop@vanderbilt.edu)
Date: Sun May 12 2002 - 17:45:49 PDT
There are two new candidates below T02-058 and T02-059. Read on.
Half of a CTIO field was subtracted from April 9 Subaru images of
SubSS1. These are *new fields*. This image was taken for CFHT
cross-telescope subtractions, but CFHT only overlapped half of the CTIO
field. I realized only today that we had Subaru images that overlapped
the other half of this CTIO exposure. Note that this is at 14h+5, and
Subaru did *not* observe this field in May.
Note that the cross-telescope subtaction has a mismatched filter. If
you scan it, you will need to spend a long time in quickscan carefully
elmiminating clusters of "green" candidates around bright stars; you
will still have a lot of things to vet in lineup, and even tiles.
One thing you sould do immeiately: SET YOUR %INC TO 25 OR 30. This is
not the usual "Rob whining about percent increase"; there is a serious
reason specific to these subtractions. The filter mismatch means that
you get a *lot* of candidates which have a %INC of 15-30 on the core of
a small (pointlike) object. A higher %INC cut is something we must
accept if we are going to use these cross-telescope subtractions.
(Nobody will be surprised that I'm not shedding tears about that.) Be
very suspicious of any candidate from this cross-telescope subtraction
with a lowish %INC unless it is patently off the core of its host. (And
a NeighDist of 1 doesn't always cut it, since sometimes the shapes
particularly of low-sigma cnadidates aren't great.)
Note that I have scanned all four fields, but others are invited to do
so. The subtractions are
H4c_2002may7-9_subxtel
H4d_2002may7-9_subxtel
H4g_2002may7-9_subxtel
H4h_2002may7-9_subxtel
THE NEW CANDIDATES:
I do not believe T02-058, and suspect it may be junk. T02-059 looks
promising.
RA and Dec should be "close".... but could be off by several
arcseconds. Those making finding charts should do a careful job of
figuring out the real RA and Dec of these candidates.
Magnitudes here are Landolt-based I-band magnitudes just like most of
what the DeepIDL software spits out from CFHT and CTIO.
name name2 RA2000 Dec2000 Prio Mag ApSig %INC
-------------------------------------------------------------
T02-058 Ioreth 14:01:15.6 +05:36:11.4 3 24.20 8.40 35
T02-059 Boromir 14:01:29.4 +05:35:16.0 4 23.92 10.88 78
NRL or Alex: could you make a finding chart at least for the latter?
I have copied my "tiles" of these candidates into $dh/tiles_ps on the
SCP PCs.
-Rob
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