5 papers
The galactic disc age-metallicity relation
Y. K. Ng, G. Bertelli, G. Carraro +1
New ages are computed for stars in the Solar Neighbourhood from the Edvardsson et al. (1993) data set. Distances derived from the Hipparcos parallaxes were adopted to obtain reliab…
Field #3 of the Palomar-Groningen Survey I. Variable stars at the edge of the Sagittarius dwarf galaxy
Y. K. Ng, M. Schultheis
A catalogue is presented with variable (RR Lyrae, semiregular and Mira) stars located inside field #3 of the Palomar-Groningen Survey, at the outer edge of the Sagittarius dwarf ga…
On the extinction towards Baade's Window
Y. K. Ng, G. Bertelli
An analysis is made on the morphology of the sequences, formed by stars distributed along the line of sight in (V,V--I) colour-magnitude diagrams from Baade's Window (l=1.0,b=-3.9)…
Stellar population synthesis
Y. K. Ng
Monte-Carlo simulations of optical and near-infrared colour-magnitude diagrams in Baade's Window (l=1.0,b=-3.9) are compared with each other. The morphological structure of the red…
Colour-Magnitude Diagrams from microlensing projects and galactic structure
Y. K. Ng
The results, obtained with the stellar population synthesis technique, are summarized for galactic structure and stellar population studies of our Galaxy. Emphasis is put on the an…