UW-WSU Nebular Emission-Line
Filters
Not on-site at APO, but can be obtained
on loan--contact Jeff Morgan at UWash,
morgan/astro.washington.edu
CENTER(Å) PASSBAND(Å) NEBULAR LINE (OR CONTINUUM)
4861 60 Hbeta
5007 60 [O III]
6301 10 [O I] -- [S III]6312A line is supressed
6563 10 Halpha -- [N II]6584 and 6583 lines are suppressed
6583 10 [N II] -- Halpha line is suppressed
6728 80 [S II]6717+6731
4686 60 He II
4760 100 blue cont or Fe II
8290 195 red cont. See also the Hodge filter set below.
9532 50 [S III]
The following filters are privately owned
but generally available
6717* 3 [S II] - bought for Io torus study
6731* 3 [S II] "
5895* 5 [Na I] "
6565** 20 part of Hodge galaxy redshifted Halpha + [N II] set
6585** 20 "
6603** 20 "
*Jeff Morgan
**Paul Hodge
Almost all are 3-cavity interference filters, so the passbands are
very rectangular (sharp cutoffs). The peak transmissions vary, being
generally highest at longer wavelengths and wider filter passbands.
The narrower filters are designed to mask nearby bright nebular
lines. All filters are 2x2 inches, 1/2-inch thick and cost a lot of
money.
The following filters are availble when not
in use locally. (Local use is generally limited to May - Sept.). Its
best to request the filters two months prior to needing
them.
The filters are available to loan to APO
observers who request them provided that they agree to cover all
costs of shipping and, if damaged, replacement. The promise to cover
these costs must be signed by someone who can allocate the funds for
replacement which, for the narrower filters, can exceed $1000. We ask
that the filters be handled ONLY by experienced APO site
personnel.
Documentation provided by Bruce Balick,
balick/astro.washington.edu
APO Filters
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