Blue Stragglers in Galactic Globular Clusters: Playing with Specific Quantities
نویسندگان
چکیده
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 increasing the amount of sampled light in loose clusters, while it drops abruptly for clusters having intermediatehigh central densities. In particular, a simple interpretative scenario where the BSS in loose clusters are produced from primordial binaries and those detected in high density globulars are due to star interactions leading to binary formation, merging. etc. seems compatible with these early results. The possibility that this observational evidence could be ascribed to systematic biases mostly related to the increasing difficulty to detect BSS candidates with increasing cluster concentration, is also discussed. Thesaurus: 03.05.1; 19.20.1
منابع مشابه
Clearing the Dust from Globular Clusters
Recent Spitzer observations of the globular cluster M15 detected dust associated with its intracluster medium. Surprisingly, these observations imply that the dust must be very short-lived compared to the time since the last Galactic plane crossing of the cluster. Here we propose a simple mechanism to explain this short lifetime. We argue that the kinetic energy of the material ejected during a...
متن کاملA Correlation between Blue Straggler and Binary Fractions in the core of Galactic Globular Clusters (Research Note)
Context. Blue Stragglers Stars (BSSs) are thought to form in globular clusters by two main formation channels: i) mergers induced by stellar collisions and ii) coalescence or mass-transfer between companions in binary systems. The detailed study of the BSS properties is therefore crucial for understanding the binary evolution mechanisms, and the complex interplay between dynamics and stellar ev...
متن کاملPrimordial binary evolution and blue stragglers
Blue stragglers can significantly enhance the spectral energy toward short wavelengths, especially in ultraviolet and blue bands. Much evidence shows that blue stragglers are relevant to primordial binaries. 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 integra...
متن کاملClose Approach during Hard Binary–Binary Scattering
It is now clear that there is a substantial population of primordial binaries in galactic globular clusters and that binary interactions are a major influence on globular cluster evolution. Collisional interactions involving stars in binaries may provide a significant channel for the formation of various stellar exotica, such as blue stragglers, X–ray binaries and millisecond pulsars. We report...
متن کاملWhere the Blue Stragglers Roam: Searching for a Link Between Formation and Environment
The formation of blue stragglers is still not completely understood, particularly the relationship between formation environment and mechanism. We use a large, homogeneous sample of blue stragglers in the cores of 57 globular clusters to investigate the relationships between blue straggler populations and their environments. We use a consistent definition of “blue straggler” based on position i...
متن کامل