ADDSTAR Problem

Mike Fitzpatrick wrote on Dec 20, 2012

[Moderator's Note: Posted on behalf of user]

Hi,

I am trying to use addstar, but I don't seem to have any luck.
Using the PSF function determined by daophot.psf (see attached), I use addstar with a photfile resulting in a picture shown in addstar_bad.jpg. The PSF is very crummy. This doesn't make sense, because when I run daophot.seestar, the resulting image is a beautiful PSF.

Do you have any idea on what I'm doing wrong?

Thank you,
Ori Fox

Attachments:

addstar_bad.jpg
[img:d7f1343e70]ftp://iraf.noao.edu/pub/addstar_bad.jpg[/img:d7f1343e70]

addstar_bad.jpg: ftp://iraf.noao.edu/pub/addstar_bad.jpg
psf.1.fits: ftp://iraf.noao.edu/pub/psf.1.fits

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Vallery Stanishev wrote on Dec 20, 2012

Do you use the correct gain value? It is used to add Poisson noise to the image. Maybe you add too much noise?

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Mike Fitzpatrick wrote on Dec 20, 2012

[Forwarded reply]

Thanks vall. Your advice was useful and will come in handy. However, I ultimately tracked the problem down to the following webpage on Spitzer PSFs:

http://irsa.ipac.caltech.edu/data/SPITZER/docs/irac/calibrationfiles/psfprf/

I never stated that I was working on Spitzer data because I did not realize it mattered.

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Last post on Dec 20, 2012