Semi-automatic removal of foreground stars from images of galaxies

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

A new procedure, designed to remove foreground stars from galaxy profiles, is presented here. Although several programs exist for stellar and faint object photometry, none of them treat star removal from the images very carefully. I present my attempt to develop such a system, and briefly compare the performance of my software to one of the well-known stellar photometry packages, DAOPHOT (Stetson, P.B. 1987, PASP, 99, 191). Major steps in my procedure are (1) automatic construction of an empirical 2D point-spread function from well-separated stars that are situated off the galaxy; (2) automatic identification of those peaks that are likely to be foreground stars, scaling the PSF and removing these stars, and patching residuals (in the automatically determined smallest possible area where residuals are truly significant); and (3) cosmetic fix of remaining degradations in the image. The algorithm and software presented here are significantly better for automatic removal of foreground stars from images of galaxies than DAOPHOT or similar packages, since (a) the most suitable stars are selected automatically from the image for the PSF fit; (b) after star removal an intelligent and automatic procedure removes any possible residuals; (c) an unlimited number of images can be cleaned in one run without any user interaction whatsoever.

Original languageEnglish
Pages (from-to)624-632
Number of pages9
JournalPublications of the Astronomical Society of the Pacific
Volume108
Issue number725
DOIs
Publication statusPublished - Jul 1996

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galaxies
stars
software
photometry
computer programs
faint objects
removal
point spread functions
fixing
degradation
scaling
profiles
interactions

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Semi-automatic removal of foreground stars from images of galaxies. / Frei, Z.

In: Publications of the Astronomical Society of the Pacific, Vol. 108, No. 725, 07.1996, p. 624-632.

Research output: Contribution to journalArticle

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