The Astrophysical Journal Letters (Jan 2023)

PHANGS–JWST First Results: Multiwavelength View of Feedback-driven Bubbles (the Phantom Voids) across NGC 628

  • Ashley. T. Barnes,
  • Elizabeth J. Watkins,
  • Sharon E. Meidt,
  • Kathryn Kreckel,
  • Mattia C. Sormani,
  • Robin G. Treß,
  • Simon C. O. Glover,
  • Frank Bigiel,
  • Rupali Chandar,
  • Eric Emsellem,
  • Janice C. Lee,
  • Adam K. Leroy,
  • Karin M. Sandstrom,
  • Eva Schinnerer,
  • Erik Rosolowsky,
  • Francesco Belfiore,
  • Guillermo A. Blanc,
  • Médéric Boquien,
  • Jakob den Brok,
  • Yixian Cao,
  • Mélanie Chevance,
  • Daniel A. Dale,
  • Oleg V. Egorov,
  • Cosima Eibensteiner,
  • Kathryn Grasha,
  • Brent Groves,
  • Hamid Hassani,
  • Jonathan D. Henshaw,
  • Sarah Jeffreson,
  • María J. Jiménez-Donaire,
  • Benjamin W. Keller,
  • Ralf S. Klessen,
  • Eric W. Koch,
  • J. M. Diederik Kruijssen,
  • Kirsten L. Larson,
  • Jing Li,
  • Daizhong Liu,
  • Laura A. Lopez,
  • Eric J. Murphy,
  • Lukas Neumann,
  • Jérôme Pety,
  • Francesca Pinna,
  • Miguel Querejeta,
  • Florent Renaud,
  • Toshiki Saito,
  • Sumit K. Sarbadhicary,
  • Amy Sardone,
  • Rowan J. Smith,
  • Sophia K. Stuber,
  • Jiayi Sun,
  • David A. Thilker,
  • Antonio Usero,
  • Bradley C. Whitmore,
  • Thomas G. Williams

DOI
https://doi.org/10.3847/2041-8213/aca7b9
Journal volume & issue
Vol. 944, no. 2
p. L22

Abstract

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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 H α 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 (∼10 ^5 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 , H _2 (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.

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