PHANGS-JWST First Results: Multiwavelength View of Feedback-driven Bubbles (the Phantom Voids) across NGC 628
Sandstrom, Karin M.; Henshaw, Jonathan D.; Kruijssen, J. M. Diederik; Leroy, Adam K.; Rosolowsky, Erik; Chevance, Mélanie; Meidt, Sharon E.; Glover, Simon C. O.; Klessen, Ralf S.; Schinnerer, Eva; Bigiel, Frank; Blanc, Guillermo A.; Emsellem, Eric; Koch, Eric W.; Pety, Jérôme; Sun, Jiayi; Whitmore, Bradley C.; Chandar, Rupali; Boquien, Médéric; Liu, Daizhong; Williams, Thomas G.; Egorov, Oleg V.; Kreckel, Kathryn; Grasha, Kathryn; Lee, Janice C.; Thilker, David A.; Dale, Daniel A.; Larson, Kirsten L.; Watkins, Elizabeth J.; Barnes, Ashley. T.; Sormani, Mattia C.; Hassani, Hamid; Cao, Yixian; Belfiore, Francesco; Groves, Brent; Saito, Toshiki; Querejeta, Miguel; Murphy, Eric J.; Smith, Rowan J.; Lopez, Laura A.; Li, Jing; Jiménez-Donaire, María J.; Usero, Antonio; Pinna, Francesca; Sarbadhicary, Sumit K.; Sardone, Amy; Renaud, Florent; Keller, Benjamin W.; Eibensteiner, Cosima; Stuber, Sophia K.; Jeffreson, Sarah; Neumann, Lukas; Treß, Robin G.; Brok, Jakob den
Germany, Belgium, Switzerland, United States, France, Canada, Italy, Chile, Finland, Australia, United Kingdom, Spain, Sweden, Japan
Abstract
We present a high-resolution view of bubbles within the Phantom Galaxy (NGC 628), a nearby (~10 Mpc), star-forming (~2 M ⊙ yr-1), face-on (i ~ 9°) grand-design spiral galaxy. With new data obtained as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS)-JWST treasury program, we perform a detailed case study of two regions of interest, one of which contains the largest and most prominent bubble in the galaxy (the Phantom Void, over 1 kpc in diameter), and the other being a smaller region that may be the precursor to such a large bubble (the Precursor Phantom Void). When comparing to matched-resolution Hα observations from the Hubble Space Telescope, we see that the ionized gas is brightest in the shells of both bubbles, and is coincident with the youngest (~1 Myr) and most massive (~105 M ⊙) stellar associations. We also find an older generation (~20 Myr) of stellar associations is present within the bubble of the Phantom Void. From our kinematic analysis of the H I, H2 (CO), and H II gas across the Phantom Void, we infer a high expansion speed of around 15 to 50 km s-1. The large size and high expansion speed of the Phantom Void suggest that the driving mechanism is sustained stellar feedback due to multiple mechanisms, where early feedback first cleared a bubble (as we observe now in the Precursor Phantom Void), and since then supernovae have been exploding within the cavity and have accelerated the shell. Finally, comparison to simulations shows a striking resemblance to our JWST observations, and suggests that such large-scale, stellar-feedback-driven bubbles should be common within other galaxies.