WP5: Calibration set

Main contributors:
Léo Girardi, Stefano Rubele, Giada Pastorelli, Yang Chen, Phil Rosenfield

The primary golas of WP5 are:

  • to build the STARKEY "Calibration Set", including only samples of resolved TP-AGB stars in which the underlying distributions of stellar ages (hence initial masses), metallicities, and distances are well characterized, with a good assessment of any contaminating population, and error estimates for all parameters. In practice, this corresponds to having a direct measurement of the Star Formation History (SFH), using stellar samples independent of the AGB stars;
  • to facilitate the simulation of these data with the theoretical tools developed by the other WPS, in particular with the TRILEGAL population synthesis tool;
  • to cooperate in the calibration itself, by developing tools to evaluate the goodness-of-fir of any given set of stellar models to the objects in the Calibration Set.

The Calibration Set should include fields in M31 from PHAT (Panchromatic Hubble Andromeda Treasury, Dalcanton et al., 2012) and dwarf galaxies up to 4 Mpc from ANGST (ACS Nearby Galaxy Survey Treasury, Dalcanton et al., 2009, 2012), where the SFH is derived from deep HST data in the optical; fields in the Magellanic Cloudes with the SFHs derived from VMC (the VISTA Survey of the Magellanic Clouds, Rubele et al., 2012, 2015); and star clusters in the Magellanic Clouds and M31. This set significantly extends the metallicity range over the present TP-AGB calibrations. The available information differs from case to case: for the Magellanic Clouds we will also have, in general, rich information on their pulsational and dust properties of TP-AGB stars, while for many other galaxies only single-epoch photometry is available.