학술논문
PHANGS-JWST First Results: The 21 $\mu$m Compact Source Population
Document Type
Working Paper
Author
Hassani, Hamid; Rosolowsky, Erik; Leroy, Adam K.; Boquien, Mederic; Lee, Janice C.; Barnes, Ashley. T.; Belfiore, Francesco; Bigiel, Frank; Cao, Yixian; Chevance, Melanie; Dale, Daniel A.; Egorov, Oleg V.; Emsellem, Eric; Faesi, Christopher M.; Grasha, Kathryn; Kim, Jaeyeon; Klessen, Ralf S.; Kreckel, Kathryn; Kruijssen, J. M. Diederik; Larson, Kirsten L.; Meidt, Sharon E.; Sandstrom, Karin M.; Schinnerer, Eva; Thilker, David A.; Watkins, Elizabeth J.; Whitmore, Bradley C.; Williams, Thomas G.
Source
Subject
Language
Abstract
We use PHANGS-JWST data to identify and classify 1271 compact 21 $\mu$m sources in four nearby galaxies using MIRI F2100W data. We identify sources using a dendrogram-based algorithm, and we measure the background-subtracted flux densities for JWST bands from 2 $\mu$m to 21 $\mu$m. Using the SED in JWST as well as HST bands, plus ALMA and MUSE/VLT observations, we classify the sources by eye. Then we use this classification to define regions in color-color space, and so establish a quantitative framework for classifying sources. We identify 1085 sources as belonging to the ISM of the target galaxies with the remainder being dusty stars or background galaxies. These 21 $\mu$m sources are strongly spatially associated with HII regions ($>92\%$ of sources), while 74$\%$ of sources are coincident with a stellar association defined in the HST data. Using SED fitting, we find that the stellar masses of the 21 $\mu$m sources span a range of 10$^{2}$ to 10$^{4}~M_\odot$ with mass-weighted ages down to 2 Myr. There is a tight correlation between attenuation-corrected H$\alpha$ and 21 $\mu$m luminosity for $L_{\nu,\mathrm{F2100W}}>10^{19}~\mathrm{W~Hz}^{-1}$. Young embedded source candidates selected at 21 $\mu$m are found below this threshold and have $M_\star < 10^{3}~M_\odot$.
Comment: 15 pages, 5 figures, Accepted as part of a PHANGS-JWST Focus Issue to appear in ApJ
Comment: 15 pages, 5 figures, Accepted as part of a PHANGS-JWST Focus Issue to appear in ApJ