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arXiv · 2105.13048

A tale of two nearby dwarf irregular galaxies WLM and IC 2574 -- as revealed by UVIT

Chayan Mondal·Annapurni Subramaniam·Koshy George
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Abstract

We present an ultra-violet study of two nearby dwarf irregular galaxies WLM and IC~2574, using the Far-UV and Near-UV data from the Ultra-Violet Imaging Telescope (UVIT). We used the F148W band Far-UV images and identified 180 and 782 young star-forming clumps in WLM and IC~2574, respectively. The identified clumps have sizes between 7 - 30 pc in WLM and 26 - 150 pc in IC~2574. We noticed more prominent hierarchical splitting in the structure of star-forming regions at different flux levels in IC~2574 than WLM. We found that the majority of the clumps have elongated shapes in the sky plane with ellipticity ($ε$) greater than 0.6 in both the galaxies. The major axis of the identified clumps is found to show no specific trend of orientation in IC~2574, whereas in WLM the majority are aligned along south-west to north-east direction. We estimated (F148W$-$N242W) colour for the clumps identified in WLM and noticed that the younger ones (with (F148W$-$N242W) $<-0.5$) are smaller in size ($<10$ pc) and are located mostly in the southern half of the galaxy between galactocentric radii 0.4 - 0.8 kpc.

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Chayan Mondal, Annapurni Subramaniam, Koshy George. 2021-05-27. A tale of two nearby dwarf irregular galaxies WLM and IC 2574 -- as revealed by UVIT. https://doi.org/10.1007/s12036-021-09761-z

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