tskymatch2
: Crossmatches 2 tables on sky position
tskymatch2
performs a crossmatch of two tables based
on the proximity of sky positions.
You specify the columns or expressions giving
right ascension and declination in degrees for each input table,
and a maximum permissible separation in arcseconds, and the resulting
joined table is output.
If you omit expressions for the RA and Dec, an attempt is made to
identify the columns to use using column
Unified Content Descriptors
(UCDs)
or names. First columns bearing appropriate UCD1 or UCD1+ values
(POS_EQ_RA
, POS_EQ_RA_MAIN
,
pos.eq.ra
or pos.eq.ra;meta.main
and
their equivalents for declination) are sought. If these cannot be found,
columns named something like "RA" or "RA2000" are sought.
If either is found, the column units are consulted and radian->degree
conversions are performed if necessary (degrees are assumed if no
unit value is given). If nothing likely can be found, then the
command will fail with an error message.
This search logic is intended as a convenience only; it is somewhat
ad hoc and subject to change. To make sure that the correct
angle values are being used, specify the ra
and dec
position parameters explicitly.
tskymatch2
is simply a cut-down version, provided for
convenience, of the more general matching task
tmatch2
.
If you want more match options or otherwise more configurability,
you can probably find it by using tmatch2
.