文章基本信息

标题：UVIT Imaging of WLM: Demographics of Star-forming Regions in the Nearby Dwarf Irregular Galaxy
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作者：Chayan Mondal ; Annapurni Subramaniam ; Koshy George 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2018
卷号：156
期号：3
页码：1-16
DOI：10.3847/1538-3881/aad4f6
语种：English
出版社：American Institute of Physics
摘要：We present a study of star-forming regions and their demographics in the nearby dwarf irregular galaxy WLMusing Ultraviolet Imaging Telescope (UVIT) multiband observations in three filters, F148W, N245M, and N263M.We find that the UV emission is extended at least up to 1.7 kpc, with the NUV emission more extended than theFUV. We create UV color maps ((F148W − N245M) and (F148W − N263M)) to study the temperaturemorphology of young stellar complexes with the help of theoretical models. We identify several complexes withtemperature T>17,500K, which are likely to be OB associations present in the galaxy. These complexes showgood spatial correlation with the Hα-emitting regions, H I distribution, and HST-detected hot stars. The hot star-forming regions are found to be clumpy in nature and show a hierarchical structure, with sizes in the range of4–50 pc, with a large number with sizes <10 pc. The southwestern part of the galaxy shows many hot star-formingregions, high levels of Hα emission, and low column density of H I , which altogether denote vigorous recent starformation. WLM is likely to have a large fraction of low-mass compact star-forming regions with massM<10 3 M e , in agreement with the size and mass of the CO clouds. We estimate the star formation rate of WLMto be ∼0.008M e yr −1 , which is similar to the average value measured for nearby dwarf irregular galaxies.
关键词：galaxies: dwarf;galaxies: individual;galaxies: star formation;Local Group