Open AccessThe analysis of isochrone fitting methods for red giant branch photometry, and tip red giant branch distance determination
Author(s) -
Frayn C. M.,
Gilmore G. F.
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06250.x
Subject(s) - physics , photometry (optics) , red giant branch , red giant , astrophysics , giant star , astronomy , red shift , stars , metallicity , galaxy
We consider the procedure of isochrone fitting and its application to the study of red giant branch (RGB) photometry in old stellar populations. This is extended to consider the problems introduced by the inclusion of lower‐magnitude regions of the colour–magnitude diagram. We refer especially to our previous paper, where the details of our isochrone interpolation and fitting code are explained. We address the systematic errors inherent in the process of isochrone fitting, and we investigate the extent to which simple stellar populations can be recovered from noisy photometric data. We investigate the effects caused by inaccurate distance estimates, isochrone model variation and photometric errors. We present results from two studies of approximately coeval stellar populations, those of the Milky Way globular cluster system, and the Ursa Minor dwarf spheroidal galaxy. In addition, we introduce a new method for estimating distances using photometry of the tip of the RGB, which is significantly more robust than the standard edge‐detection filter.