PHANGS-JWST First Results: A statistical view on bubble evolution in NGC628
Creators: name: Watkins, Elizabeth J.
name: Barnes, Ashley
name: Henny, Kiana F.
name: Kim, Hwihyun
name: Kreckel, Kathryn
name: Meidt, Sharon E.
name: Klessen, Ralf S.
name: Glover, Simon C. O.
name: Williams, Thomas G.
name: Keller, B. W.
name: Leroy, Adam K.
name: Rosolowsky, Erik W.
name: Boquien, Mederic
name: Anand, Gagandeep S.
name: Belfiore, Francesco
name: Bigiel, Frank
name: Blanc, Guillermo
name: Cao, Yixian
name: Chandar, Rupali
name: Chen, Ness Mayker
name: Chevance, Mélanie
name: Congiu, Enrico
name: Dale, Daniel A.
name: Deger, Sinan
name: Egorov, Oleg
name: Emsellem, Eric
name: Faesi, Christopher M.
name: Grasha, Kathryn
name: Groves, Brent
name: Hassani, Hamid
name: Henshaw, Jonathan
name: Herrera, Cinthya N.
name: Hughes, Annie
name: Jeffreson, Sarah
name: Jimenez-Donaire, Maria Jesus
name: Koch, Eric W.
name: Kruijssen, J. M. Diederik
name: Larson, Kirsten L.
name: Liu, Daizhong
name: Lopez, Laura A.
name: Pessa, Ismael
name: Pety, Jerome
name: Querejeta, Miguel
name: Saito, Toshiki
name: Sandstrom, Karin M.
name: Scheuermann, Fabian
name: Schinnerer, Eva
name: Sormani, Mattia C.
name: Stuber, Sophia K.
name: Thilker, David A.
name: Usero, Antonio
name: Whitmore, Bradley C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The first JWST observations of nearby galaxies have unveiled a rich population of bubbles that trace the stellar feedback mechanisms responsible for their creation. Studying these bubbles therefore allows us to chart the interaction between stellar feedback and the interstellar medium, and the larger galactic flows needed to regulate star formation processes globally. We present the first catalog of bubbles in NGC628, visually identified using MIRI F770W PHANGS-JWST observations, and use them to statistically evaluate bubble characteristics. We classify 1694 structures as bubbles with radii between 6-552 pc. Of these, 31% contain at least one smaller bubble at their edge, indicating that previous generations of star formation have a local impact on where new stars form. On large scales, most bubbles lie near a spiral arm, and their radii increase downstream compared to upstream. Furthermore, bubbles are elongated in a similar direction to the spiral arm ridge-line. These azimuthal trends demonstrate that star formation is intimately connected to the spiral arm passage. Finally, the bubble size distribution follows a power-law of index $p=-2.2\pm0.1$, which is slightly shallower than the theoretical value by 1-3.5$σ$ that did not include bubble mergers. The fraction of bubbles identified within the shells of larger bubbles suggests that bubble merging is a common process. Our analysis therefore allows us to quantify the number of star-forming regions that are influenced by an earlier generation, and the role feedback processes have in setting the global star formation rate. With the full PHANGS-JWST sample, we can do this for more galaxies.
description: 25 pages total, 13 Figures and 1 Table. Accepted for publication in ApJL as part of a PHANGS-JWST First Results Focus issue