Wide Field Camera 3
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Posted by Susan Stolovy on July 06, 1999 at 10:29:08:


At the risk of stating the obvious, it is
crucial that appropriate narrowband continuum filters are
chosen to match each spectral line filter (e.g. F190N with
F187N for Paschen Alpha in NICMOS).  Trying to extrapolate 
the continuum from medium-band or wide-band filters
is really unsatisfactory.  This is especially true when trying
to extract information near the diffraction patterns of stellar
images and where assumptions about the spectral index of the continuum 
may be incorrect (e.g. if there are small-scale variations in 
extinction). It looks like the IR filter list currently on the web 
(http://clavius.stsci.edu/WFC3/HTML/filters/ir/ir.html)
does not list the desired continuum filters.  It's important,
of course, that the continuum filters avoid contamination
from other lines.  Ideally, you'd want continuum filters of
similar transmission properties on both blue and red ends of
the line filter, but probably that is too much too ask.

Just my 2-cents' worth.

Cheers,

Susan Stolovy