Origin of the IRAS Vela Shell
- Author(s)
- Bore Annie Gao, Catherine Zucker, Tirupati Kumara Sridharan, Cameren Swiggum, Shmuel Bialy, Theo J. O’Neill, J. E.G. Peek, Luciana Bianchi, Robert Benjamin, Lewis McCallum, Alyssa Goodman, João Alves, Charles Lada, Gordian Edenhofer, Rowan Smith, Elizabeth Watkins, Kenneth Wood, Doni Anderson
- Abstract
The IRAS Vela Shell (IVS) is a structure of enhanced far-IR (FIR) emission located toward the Gum Nebula, a prominent region of Hα emission in the local Milky Way shaped by various galactic stellar feedback over the past several million years. We constrain the 3D spatial geometry of the IVS using a parsec-resolution 3D dust map and contextualize it within the broader Gum Nebula. Our analysis reveals a dense, bowl-like IVS structure below the Galactic plane, with a more diffuse component above. We obtain a total shell mass of 5 . 1 − 2.4 + 2.4 × 1 0 4 M ⊙ and, incorporating previous studies on shell expansion, a momentum of 6 . 0 − 3.4 + 4.7 × 1 0 5 M ⊙ km s − 1 . We find a spatial correlation between the morphology of the dust-traced IVS and the Gum Nebula’s Hα emission when projected onto the sky. We quantify contributions of feedback from stellar winds, an expanding H ii region, and supernovae to the IVS formation, finding that stellar winds are subdominant. Our momentum analysis shows that both an H ii region and supernova feedback could drive the shell’s expansion. Using astrometric constraints from Gaia and Hipparcos, we trace back nearby feedback sources and find that the massive stars γ2 Velorum and ζ Puppis are currently within the IVS, producing enough ionizing luminosity to form an H ii region of comparable size. Alternatively, if the IVS’ momentum is primarily driven by supernovae, one to two events would be required. We also identify several young massive clusters that could have hosted supernovae within the past 3 Myr.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Johns Hopkins University, Harvard-Smithsonian Center for Astrophysics, National Radio Astronomy Observatory, Green Bank, Technion - Israel Institute of Technology, Space Telescope Science Institute, University of Wisconsin, Whitewater, University of St. Andrews, Max-Planck-Institut für Astrophysik, Ludwig-Maximilians-Universität München, University of Manchester, University of Michigan
- Journal
- Astrophysical Journal
- Volume
- 987
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.3847/1538-4357/add7d8
- Publication date
- 07-2025
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/02d7e787-7fa0-415d-995b-dc9fe1703da7