相关论文: Horizontal branch morphology in galactic globular …

We review the most outstanding issues related to the study of the morphology of the Horizontal Branch (HB) in the Color-Magnitude Diagrams of Galactic Globular Clusters and its use as age indicator. It is definitely demonstrated (see also…

The horizontal branch (HB) morphology of globular clusters (GCs) is most strongly influenced by metallicity. The second parameter phenomenon acknowledges that metallicity alone is not enough to describe the HB morphology of all GCs. In…

The horizontal branch (HB) morphology of globular clusters (GCs) is mainly described by metallicity. The fact that some clusters with almost the same metallicity exhibit different HB demonstrates that other parameters are at work. We…

The Horizontal Branch (HB) second parameter of Globular Clusters (GCs) is a major open issue in stellar evolution. Large photometric and spectroscopic databases allow a re-examination of this issue. We derive median and extreme (90% of the…

The interpretation of globular cluster horizontal branch (HB) morphology is a classical problem that can significantly blur our understanding of stellar populations. In this paper, we present a new multivariate analysis connecting the…

We schematically review some of the main steps in the study of the Horizontal Branch Morphology in Galactic Globular Clusters. Since the first realization of the existence of the so-called Second Parameter Problem (2nd-P) up to now, one…

Theory and observations indicate that the distribution of stars along the horizontal branch of Galactic globular clusters mainly depends on the metal content. However, the existence of globular clusters with similar metal content and…

We study the correlations between the distribution of stars on the horizontal branch (HB), the HB morphology, with some other properties of globular clusters (GCs) in a large sample of GCs. We strengthen previous results that a general…

The Second Parameter (2ndP) Problem recognizes the remarkable role played by horizontal branch (HB) morphology in the development of our understanding of globular clusters, and the Galaxy, over the last 50 years. I will describe the…

The horizontal branch (HB) morphology of globular clusters (GCs) is mainly determined by metallicity. However, the fact that GCs with almost the same metallicity exhibit different HB morphologies demonstrates that at least one more…

The horizontal branch (HB) morphology of globular clusters (GC) is mainly governed by metallicity. The second parameter problem, well known since the 60's, states that metallicity alone is not enough to describe the observed HB morphology…

Broadband colours are often used as metallicity proxies in the study of extragalactic globular clusters. A common concern is the effect of variations in horizontal branch (HB) morphology--the second-parameter effect--on such colours. We…

We have applied a new method to analyze the horizontal branch (HB) morphology in relation to the distribution of stars near the red giant branch (RGB) tip for the globular clusters M22, M5, M68, M107, M72, M92, M3 and 47 Tuc. This new…

We present our recent revision of model constructions for the horizontal-branch (HB) morphology of globular clusters, which suggests the HB morphology is more sensitive to age compared to our earlier models. We also present our high…

We perform an evolutionary multivariate analysis of a sample of 54 Galactic globular clusters with high-quality colour-magnitude diagrams and well-determined ages. The four parameters adopted for the analysis are: metallicity, age, maximum…

We revisit the "second parameter" pair of globular clusters NGC 288/NGC 362 on the basis of theoretical models for red giant branch (RGB) and horizontal branch (HB) stars. The results of the most extensive set of RGB/HB simulations computed…

Context. Stellar collision rates in globular clusters (GCs) do not appear to correlate with horizontal branch (HB) morphology, sug- gesting that dynamics does not play a role in the second-parameter problem. However, core densities and…

As stars which have planetary systems evolve along the red giant branch and expand, they interact with the close planets. The planets deposit angular momentum and energy into the red giant stars' envelopes, both of which are likely to…

Surface temperature distribution of horizontal-branch (HB) stars is very sensitive to age in old stellar systems, which makes it an attractive age indicator. In this paper, we present the recent revision of our model calculations for the HB…

Theoretical integrated broad-band colors ranging from far-UV to near-IR have been computed for old stellar systems from our evolutionary population synthesis code. These models take into account, for the first time, the detailed systematic…