34,732 research outputs found
Young massive star clusters in nearby galaxies. II.Software tools, data reductions and cluster sizes
A detailed description is given of the data analysis leading to the discovery
of young massive star clusters (YMCs) in a sample of 21 nearby galaxies. A new
useful tool, ishape, for the derivation of intrinsic shape parameters of
compact objects is presented, and some test results are shown. Completeness
tests for the cluster samples are discussed, and ishape is used to estimate
cluster sizes. Half-light radii of 0 - 20 pc are derived for clusters in 2 of
the most cluster-rich galaxies, NGC 1313 and NGC 5236, which is within the
range spanned by globular clusters in the Milky Way and by YMCs in the LMC and
some starburst galaxies. Photometric data for all clusters, along with
positions and estimated half-light radii, are tabulated.Comment: Accepted for publication in A&A Suppl. Ser. 24 pages, 14 figure
School Accountability and Administrator Incentives in California
Examines the impact of the No Child Left Behind Act's incentives for principals, superintendents, and school boards on accountability. Calls for transparency on the effectiveness of schools, districts, and interventions in improving student achievement
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