Galaxy Clusters Associated with Short GRBs. II. Predictions for the Rate of Short GRBs in Field and Cluster Early-Type Galaxies

We determine the relative rates of short GRBs in cluster and field early-type galaxies as a function of the age probability distribution of their progenitors, P(\tau) \propto \tau^n. This analysis takes advantage of the difference in the growth of stellar mass in clusters and in the field, which arises from the combined effects of the galaxy stellar mass function, the early-type fraction, and the dependence of star formation history on mass and environment. This approach complements the use of the early- to late-type host galaxy ratio, with the added benefit that the star formation histories of early-type galaxies are simpler than those of late-type galaxies, and any systematic differences between progenitors in early- and late-type galaxies are removed. We find that the ratio varies from R(cluster)/R(field) ~ 0.5 for n = -2 to ~ 3 for n = 2. Current observations indicate a ratio of about 2, corresponding to n ~ 0 - 1. This is similar to the value inferred from the ratio of short GRBs in early- and late-type hosts, but it differs from the value of n ~ -1 for NS binaries in the Milky Way. We stress that this general approach can be easily modified with improved knowledge of the effects of environment and mass on the build-up of stellar mass, as well as the effect of globular clusters on the short GRB rate. It can also be used to assess the age distribution of Type Ia supernova progenitors.Comment: ApJ accepted versio

Women, age, and the managerial career in postwar Britain: Exploring the roots of the barriers to women's opportunities in management

This essay explores how the assumption that hierarchical position should be linked to a position-holder's age acted as a barrier to women advancing into management positions. The close and unquestioned association between an individual's age and what was considered an appropriate place on a bureaucratic hierarchy is one of the less often acknowledged barriers to women's upward mobility. The study focuses on Britain in the years following the Second World War, because the increased participation of women in the workforce during the war had engendered optimism about women's opportunities for long-term gains and advancement. Many women came out of the Second World War with a high degree of organizational capital that should have seen them advance into managerial positions. But as this study shows, through evidence gathered from archival as well as published historical documents, in the reality of the postwar world being the wrong age for the job constituted a significant barrier to women's advancement

A Study of two particle momentum correlations in hadronic Z0 decays

Contains fulltext : 124395.pdf (publisher's version ) (Open Access