相关论文: Blue Straggler Bimodality: a Brownian Motion Model

Globular Cluster (GC) Color-Magnitude Diagrams (CMDs) are reasonably well understood in terms of standard stellar-evolution. However, there are still some open issues, such as fully accounting for the Horizontal Branch (HB) morphology in…

We present preliminary results obtained from the comparison of the specific frequencies of Blue Straggler Stars (BSS) detected so far in a sample of 26 Galactic globular clusters. The number of BSS seems to increase almost linearly with…

We present spectroscopic observations acquired with FLAMES and XSHOOTER at the Very Large Telescope for a sample of 15 Blue Straggler Stars (BSSs) in the globular cluster (GC) M30. The targets have been selected to sample the two BSS…

A number of theories have been put forward to explain the bi-modal stellar rotational distribution observed in young massive clusters. These include stellar mergers and interactions induced in binary systems, and the role of angular…

We consider scaled Brownian motion (sBm), a random process described by a diffusion equation with explicitly time-dependent diffusion coefficient $D(t) = D_0 t^{\alpha - 1}$ (Batchelor's equation) which, for $\alpha < 1$, is often used for…

Molecular dynamics simulations were employed to investigate the phase separation process of a two-dimensional active Brownian dumbbell model. We evaluated the time dependence of the typical size of the dense component using the scaling…

We have used high resolution WFPC2-HST and wide field ground-based observations to construct a catalog of blue straggler stars (BSS) which spans the entire radial extent of the globular cluster NGC 6752. The BSS sample is the most extensive…

In this paper we report on the most significant results from a statistical analysis of the main properties of globular cluster blue straggler stars (BSS) extracted from the HST snapshot database of photometrically homogeneous CMDs (Piotto…

We prove the existence and uniqueness of a strong solution of a stochastic differential equation with normal reflection representing the random motion of finitely many globules. Each globule is a sphere with time-dependent random radius and…

The stochastic trajectories of molecules in living cells, as well as the dynamics in many other complex systems, often exhibit memory in their path over long periods of time. In addition, these systems can show dynamic heterogeneities due…

Since recent years, mass segregation driven by two-body relaxation in star clusters has been proposed to be measured by the so-called dynamical clock, $A^+$, a measure of the area enclosed between the cumulative radial distribution of blue…

Blue straggler stars (BSSs) are the most massive stars in a cluster formed via binary or higher-order stellar interactions. Though the exact nature of such formation scenarios is difficult to pin down, we provide observational constraints…

Fractional Brownian motion, a Gaussian non-Markovian self-similar process with stationary long-correlated increments, has been identified to give rise to the anomalous diffusion behavior in a great variety of physical systems. The…

Time-dependent meridional circulation and differential rotation in radiative zones are central open issues in stellar evolution theory. We streamline this challenging problem using the downward control principle of atmospheric science,…

We constructed a Hubble Space Telescope (HST) astro-photometric catalog of the central region of the Galactic globular cluster NGC 1261. This catalog, complemented with Gaia DR2 data sampling the external regions, has been used to estimate…

Stellar orbits in the Galactic disc evolve from their birth to the current shape through both radial migration and dynamical heating. The history of their secular evolution is imprinted in the current kinematics and age-metallicity…

We used a combination of high-resolution optical images acquired with the Hubble Space Telescope and near-IR wide-field data to investigate the stellar density profile and the population of blue straggler star (BSS) in the Galactic globular…

Aims: This paper presents a new homogeneous catalogue of blue straggler stars (BSS) in Galactic open clusters. Methods: Photometric data for 216 clusters were collected from the literature and 2782 BSS candidates were extracted from 76 of…

In this paper, we systematically studied blue stragglers produced from primordial binary evolution via a binary population synthesis approach, and examined their contribution to the integrated spectral energy distributions of the host…

We have used high spatial resolution data from the Hubble Space Telescope and wide-field ground-based observations to search for blue straggler stars (BSS) over the entire radial extent of the large stellar system omega Centauri. We have…