Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-01-23
Astron.J.133:2053-2060,2007
Astronomy and Astrophysics
Astrophysics
26 pages, 8 figures, accepted to AJ
Scientific paper
10.1086/513076
We have used deep high-resolution Hubble Space Telescope ACS observations to image the cluster NGC 1978 in the Large Magellanic Cloud. This high-quality photometric data set allowed us to confirm the high ellipticity (~0.30+-0.02) of this stellar system. The derived Color Magnitude Diagram allowed a detailed study of the main evolutionary sequences: in particular we have detected the so called Bump along the Red Giant Branch (at V_{555}=19.10+-0.10). This is the first detection of this feature in an intermediate-age cluster. Moreover the morphology of the evolutionary sequence and their population ratios have been compared with the expectations of different theoretical models (namely BaSTI, PEL and Padua) in order to quantify the effect of convective overshooting. The best agreement (both in terms of morphology and star counts) has been found the PEL (Pisa Evolutionary Library) isochrone with Z=0.008 (consistenly with the most recent determination of the cluster metallicity, [M/H]=-0.37 dex) and a mild overshooting efficiency (Lambda_{os}=0.1). By adopting this theoretical set an age of 1.9+-0.1 Gyr has been obtained.
Ferraro Francesco R.
Fusi Pecci Flavio
Mucciarelli Alessio
Origlia Livia
No associations
LandOfFree
The globular cluster NGC 1978 in the Large Magellanic Cloud does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The globular cluster NGC 1978 in the Large Magellanic Cloud, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The globular cluster NGC 1978 in the Large Magellanic Cloud will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-205481