Open AccessTransforming observational data and theoretical isochrones into the ACS/WFC Vega‐mag system
Author(s) -
Bedin Luigi R.,
Cassisi Santi,
Castelli Fiorella,
Piotto Giampaolo,
Anderson Jay,
Salaris Maurizio,
Momany Yazan,
Pietrinferni Adriano
Publication year - 2005
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 - 10.1111/j.1365-2966.2005.08735.x
Subject(s) - physics , vega , advanced camera for surveys , astrophysics , globular cluster , magnitude (astronomy) , red giant branch , wide field camera 3 , calibration , astronomy , hubble space telescope , galaxy , quantum mechanics
We propose a zero‐point photometric calibration of the data from the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) on board the Hubble Space Telescope , based on a spectrum of Vega and the most up‐to‐date in‐flight transmission curves of the camera. This calibration is accurate at the level of a few hundredths of a magnitude. The main purpose of this effort is to transform the entire set of evolutionary models into a simple observational photometric system for ACS/WFC data, and to make them available to the astronomical community. We provide the zero‐points for the most used ACS/WFC bands, and give basic recipes for calibrating both the observed data and the models. We also present the colour–magnitude diagram from ACS data of five Galactic globular clusters, spanning the metallicity range −2.2 <[Fe/H] < −0.04 , and we provide fiducial points representing their sequences from several magnitudes below the turn‐off to the red giant branch tip. The observed sequences are compared with the models in the newly defined photometric system.