A study of the star forming regions in the spiral galaxy NGC 2336 using the Ultraviolet Imaging Telescope (UVIT)

TL;DR

This study uses UV imaging to analyze recent star formation in NGC 2336, identifying star forming knots, estimating their properties, and linking star formation to spiral density waves.

Contribution

It provides detailed measurements of star forming regions in NGC 2336 using UVIT, highlighting the distribution, ages, and masses of knots, and connecting star formation to spiral structure.

Findings

72 star forming knots identified mainly along spiral arms

Star forming knots have mean sizes of ~485 pc and masses around 10^6 M_sun

Star formation rates vary from 6.9e-4 to 2.2e-2 M_sun/yr

Abstract

We present a far-UV (FUV) and near-UV (NUV) imaging study of recent star formation in the nearby spiral galaxy NGC 2336 using the Ultraviolet Imaging Telescope (UVIT). NGC 2336 is nearly face-on in morphology and has a multi-armed, branching spiral structure which is associated with star forming regions distributed mainly along the spiral arms and the co-rotation ring around the bar. We have identified 72 star forming knots in the disk, of which only two are in the inter-arm regions and 6 in the co-rotation ring. We have tabulated their positions and estimated their luminosities, sizes, star formation rates, colors, ages and masses. The ages and masses of these star forming knots were estimated using the Starburst99 stellar evolutionary synthesis models. The star forming knots have FUV and NUV mean sizes of 485 pc and 408 pc respectively and mean stellar masses of 9.8 $\times 10^{5}$ M$_{\odot}$ that range from 5.6 $\times 10^{5}$ to 1.1 $\times 10^{6}$ M$_{\odot}$. Their star formation rates vary from 6.9 $\times 10^{-4}$ to 2.2 $\times 10^{-2}$ M$_{\odot}$/yr in NUV and from 4.5 $\times 10^{-4}$ to 1.8 $\times 10^{-2}$ M$_{\odot}$/yr in FUV. The FUV-NUV colour of the knots is found to be bluest in the central region and becomes progressively redder as the radius increases. Our results suggest that star formation in disks with spiral structure is driven by the spiral density wave and is best traced by UV imaging as it encompasses clusters spanning a wide range of star forming ages and stellar masses.