Saint Mary's University

About: Saint Mary's University is a education organization based out in Halifax, Nova Scotia, Canada. It is known for research contribution in the topics: Population & Stars. The organization has 1931 authors who have published 4993 publications receiving 143226 citations.

New galactic star clusters discovered in the VVV survey. Candidates projected on the inner disk and bulge

Abstract: Context VISTA Variables in the Via Lactea (VVV) is one of six ESO Public Surveys using the 4 meter Visible and Infrared Survey Telescope for Astronomy (VISTA) The VVV survey covers the Milky Way bulge and an adjacent section of the disk, and one of the principal objectives is to search for new star clusters within previously unreachable obscured parts of the GalaxyAims The primary motivation behind this work is to discover and analyze obscured star clusters in the direction of the inner Galactic disk and bulgeMethods Regions of the inner disk and bulge covered by the VVV survey were visually inspected using composite JH K S color images to select new cluster candidates on the basis of apparent overdensities DR1, DR2, CASU, and point spread function photometry of 10 × 10 arcmin fields centered on each candidate cluster were used to construct color–magnitude and color–color diagrams Follow-up spectroscopy of the brightest members of several cluster candidates was obtained in order to clarify their natureResults We report the discovery of 58 new infrared cluster candidates Fundamental parameters such as age, distance, and metallicity were determined for 20 of the most populous clusters

Social networks and transitions to co-management in Jamaican marine reserves and small-scale fisheries

Abstract: How social networks support or constrain the transition to co-management of small-scale fisheries and marine reserves is poorly understood. In this paper, we undertake a comparative analysis of the social network structures associated with the transition to co-management in three Jamaican marine reserves. Data from quantitative social relational surveys (n = 380) are integrated with data from semi-structured interviews (n = 63) and focus groups (n = 10) to assess how patterns of relational ties and interactions between and among fishermen and other local level actors (e.g., managers, wardens, NGO staff) support and constrain the transition to co-management. Our research suggests that the transitions to co-management were supported by a combination of three network structure and relational attributes: (i) the presence and position of institutional entrepreneurs; (ii) a dense central core of network actors; and (iii) the prevalence of horizontal ties and vertical linkages held by the community-based organizations formally responsible for the management of the marine reserves. Our findings also show that overall low network cohesion in the three reserves and limited social influence among the wardens may be problematic for sustained collective action that extends beyond the core set of network actors. These findings suggest the importance of strategies to enhance collective action, specifically through attention to the attributes of the corresponding social networks, as a means to contribute to successful transitions to co-management of marine reserves and small-scale fisheries. Our results provide more precise guidance, through social network analysis, on where in the respective networks social capital and leadership may require support or enhancement, and thus on how to target interventions for greatest effect.

The structure and evolution of the Lagoon Nebula. I. Submillimeter continuum and CO line mapping

Abstract: We present submillimeter- and millimeter-wave maps tracing the molecular gas and dust around the edge of the H ii region M8. The molecular material is clumped into cores on the scale of the beam (about 0.1 pc) whose temperatures can be estimated from CO observations. The masses of the clumps, estimated from their continuum fluxes, are consistent with a power-law mass function with index � 1:7 � 0:6, which agrees with determinations for other molecular clouds at similar resolutions, using molecular lines as tracers. The submillimeter clumps are sited at the interface between the H ii region and the background molecular cloud, where they are exposed to the ultraviolet flux of OB stars. The physical parameters of the clumps are compared to published models of molecular clouds undergoing photoevaporation, suggesting that the pressure of the ionized gas exceeds the internal pressure of the clumps and, therefore, that a shock front will be driven into the clumps. The clumps themselves currently appear to be gravitationally unbound, but the compression may be sufficient to induce collapse. Subject headings: H ii regions — ISM: individual (M8) — ISM: structure — stars: formation — submillimeter