iraf.net

>From smecker@dao.nrc.ca Wed Jan 6 18:16:44 1993
To: fitz@tucana
Subject: fxcor and xcsaoHi Mike --Can you help me with a few questions about cross correlation
routines in IRAF, please? What is the basic difference between
the fxcor routine in rv and the xcsao in rvsao? I'm used to
using fxcor on stars, but am planning on analyzing some galaxy
data at redshifts of z~=0.3. If there are differences in the two
routines, are there specific differences that make one better
adapted to galaxy work? Thanks very much, Tammy Smecker-Hane PS -- I've moved from Johns Hopkins to a post doc at the
Dominion Astrophysical Observatory so my email address is now
smecker@dao.nrc.ca. Unix is the norm here so I won't be emailing you
with VAX installation problems anymore! Take care.>From fitz Wed Jan 6 21:26:12 1993
To: smecker@dao.nrc.ca
Subject: Re: fxcor and xcsaoHi Tammy,
Both routines are based on the same Tonry & Davis algorithm so there
is no fundamental difference between them. FXCOR will handle z~=0.3 data
as well as it does low-velocity stellar data, I can't really comment on
XCSAO since I haven't done a full comparison of the two packages. You
should be aware that parameter differences (e.g. peak fitting params) will
make a difference in the results you get so you should take care in setting
these. If you can give me some details about the data I might be able to
suggest something. Cheers,
-Mike