Properties of YMCs Derived From Photometry
نویسندگان
چکیده
I will show that photometry – if extending over a reasonable choice of passbands – can give fairly precise information about young star clusters and their evolutionary state. Optical colors alone are known to leave severe ambiguities due to degeneracies between age, metallicity and extinction. High quality photometry including U,B, V or I, and a NIR band, however, in combination with an extensive grid of evolutionary synthesis models for star clusters and a dedicated tool to analyse spectral energy distributions allows to assess and largely disentangle star cluster ages, metallicities, extinction values and, hence, to derive their masses. Gaseous emission contributions sensibly affect broad band colors during the youngest stages, depending on metallicity. Mass functions of young star cluster systems may considerably differ in shape from luminosity functions. An ESO ASTROVIRTEL project provides multi-color photometry for a large number of young, intermediate age and old star cluster systems. As a first example I show results obtained for NGC 1569.
منابع مشابه
Young massive star clusters in nearby galaxies ⋆
1 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...
متن کاملEvaluation of the total analytical error in the flame photometry method
Background and Objectives: For total analytical error, imprecision (SD) and bias, performance goals for laboratory tests have most often been developed. A total analytical error goal requires that the combination of errors from all sources (random and systematic errors) be within some acceptable limit. M...
متن کاملBasic Tools for Studies on the Formation and Disruption of Star Clusters: the Luminosity Function
The luminosity function (LF) of young star clusters is often approximated by a power law function. For clusters in a wide range of galactic environments this has resulted in fit indices near −2, but on average slightly steeper. A fundamental property of the −2 power law function is that the luminosity of the brightest object (Lmax) scales linearly with the total number of clusters, which is clo...
متن کاملFrom nuclear clusters to halo globulars: Star clusters as basic galactic building blocks
I assess the similarities and differences between the star-formation modes in quiescent spiral galaxies versus those in violent starburst regions, including galactic nuclei. As opposed to the quiescent star-formation mode, current empirical evidence on the star-formation processes in the extreme, high-pressure environments induced by galaxy encounters strongly suggests that star cluster formati...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2005