From dad Tue May 15 08:26 PDT 2001
From: dad@ipac.caltech.edu
Date: Tue, 15 May 2001 08:26:28 -0700 (PDT)
To: gxh@ipac.caltech.edu, lee@ipac.caltech.edu
Subject: web page on irs

Hi George & Lee,

So I fixed a couple small errors on the web page, and I've placed a copy at
/xxxx/xxx/xxxxx/xxxxxxxxxxxxxxx/index.html

For each galaxy I've overlaid on a DSS image the two slit arrangments that
indicate the maximum IRS PA range for a given season (summer, winter, etc).
And I've also overlaid the two slit arrangements that indicate the maximum
IRS PA range for the opposite season.

[ I originally had only overlaid the slits for one season because, at least for
  the first few galaxies I investigated, things were only flipped by 180 
  degrees; a 180 degree flip is essentially the same thing for slit 
  spectroscopy.  But it turns out that some of the accessible PAs vary by more 
  than 180 degrees for the two opposite seasons.  So I've included the overlays 
  for both seasons to be perfectly complete. ]

In a few cases the galaxy is observable for nearly the entire year, and I've
only put down two parallel slits, indicating that we can access all possible
IRS PAs.  Also, in a few cases I have overlaid three slit positions per season
just to make it perfectly clear where one season's PA range lies.

Each galaxy image is followed by one line of text and one table.  The line of
text indicates the windows of opportunity we have for the object (in the
format month/day; I've left off the year because I'm lazy but it should be
obvious), and the table gives sample IRS PAs, separated by ~0.5 months.  
Orbital symmetries allow sample PAs for only two seasons to effectively 
capture all of the relevant info.

Fortunately, the MIPS SED slit PA is 180 degrees off of the IRS PA.  We can
and should execute MIPS SED observations at the same time as the IRS 
observations.

Cheers,
Danny