A Stellar Audit: the Computation of Encounter Rates for 47 Tucanae and ! Centauri Received ** *** 1994; in Original Form 1994 *** **
نویسنده
چکیده
Using King-Mitchie Models, we compute encounter rates between the various stellar species in the globular clusters ! Cen, and 47 Tuc. We also compute event rates for encounters between single stars and a population of primordial binaries. Using these rates, and what we have learnt from hydrodynamical simulations of encounters performed earlier, we compute the production rates of objects such as low-mass X-ray binaries (LMXBs), smothered neutron stars and blue stragglers (massive main-sequence stars). If 10% of the stars are contained in primordial binaries, the production rate of interesting objects from encounters involving these binaries is as large as that from encounters between single stars. For example, encounters involving binaries produce a signiicant number of blue stragglers in both globular cluster models. The number of smothered neutron stars may exceed the number of low-mass X-ray binaries (LMXBs) by a factor of 5-20, which may help explain why millisecond pulsars are observed to outnumber LMXBs in globular clusters.
منابع مشابه
On the Relative Distances of Ω Centauri and 47 Tucanae
We present precise optical and near-infrared ground-based photometry of two Globular Clusters (GCs): ω Cen and 47 Tuc. These photometric catalogs are unbiased in the Red Giant Branch (RGB) region close to the tip. We provide new estimates of the RGB tip (TRGB) magnitudes— mI(TRGB) = 9.84± 0.05, ω Cen; mI(TRGB) = 9.46± 0.06, 47 Tuc—and use these to determine the relative distances of the two GCs...
متن کاملPractice Appointment Rates for High-risk Asthmatics: What could be the Predictor(s)?
Practice appointment rates could have a significant impact on national health care costs and services offered by doctors. In this respect a study was designed to determine the relationship between practice appointments and possible predictors in high-risk asthmatics. An observational retrospective analysis of the predictors for the practice appointments in asthmatic patients with at least one h...
متن کاملPractice Appointment Rates for High-risk Asthmatics: What could be the Predictor(s)?
Practice appointment rates could have a significant impact on national health care costs and services offered by doctors. In this respect a study was designed to determine the relationship between practice appointments and possible predictors in high-risk asthmatics. An observational retrospective analysis of the predictors for the practice appointments in asthmatic patients with at least one h...
متن کاملInstitutions in the Economic System of Islam
In this article, the set of institutions which embody the form and contents of the economic system of Islam is introduced. By institutions, it is meant the economic freedoms, the government, ownership, motivation, the mechanism for coordinating economic activities, power, organization and bureaucracy. After explaining Islam’s outlook regarding these institutions, the form and the contents of th...
متن کاملDynamics of Flexible Manipulators
This paper presents an application of Continuum (i.e. Lagrangian) and Finite Element Techniques to flexible manipulator arms for derivation of the corresponding Dynamic Equations of Motion. Specifically a one-link flexible arm is considered for detailed analysis, and the results are extended for the case of a two - link flexible manipulator. Numerical examples are given for the case of both one...
متن کامل