The Radcliffe wave as the gas spine of the Orion arm

C. Swiggum, J. Alves, E. D'Onghia, R. A. Benjamin, L. Thulasidharan, C. Zucker, E. Poggio, R. Drimmel, III Gallagher J. S., A. Goodman

The Radcliffe wave is a ∼3 kpc long coherent gas structure containing most of the star-forming complexes near the Sun. In this Letter we aim to find a Galactic context for the Radcliffe wave by looking into a possible relationship between the gas structure and the Orion (local) arm. We use catalogs of massive stars and young open clusters based on Gaia Early Data Release 3 (EDR3) astrometry, in conjunction with kiloparsec-scale 3D dust maps, to investigate the Galactic XY spatial distributions of gas and young stars. We find a quasi-parallel offset between the luminous blue stars and the Radcliffe wave, in that massive stars and clusters are found essentially inside and downstream from the Radcliffe wave. We examine this offset in the context of color gradients observed in the spiral arms of external galaxies, where the interplay between density wave theory, spiral shocks, and triggered star formation has been used to interpret this particular arrangement of gas and dust as well as OB stars, and outline other potential explanations as well. We hypothesize that the Radcliffe wave constitutes the gas reservoir of the Orion (local) arm, and that it presents itself as a prime laboratory to study the interface between Galactic structure, the formation of molecular clouds in the Milky Way, and star formation.

Department of Astrophysics
External organisation(s)
University of Wisconsin, Madison, University of Wisconsin, Whitewater, Space Telescope Science Institute, Université Côte d'Azur, INAF-Osservatorio Astrofisico di Torino, Harvard-Smithsonian Center for Astrophysics
Astronomy and Astrophysics
Publication date
Peer reviewed
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
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