Outflows from Super Star Clusters in the Central Starburst of NGC 253
Journal article, 2021
Young massive clusters play an important role in the evolution of their host galaxies, and feedback from the high-mass stars in these clusters can have profound effects on the surrounding interstellar medium. The nuclear starburst in the nearby galaxy NGC 253 at a distance of 3.5 Mpc is a key laboratory in which to study star formation in an extreme environment. Previous high-resolution (1.9 pc) dust continuum observations from the Atacama Large Millimeter/submillimeter Array (ALMA) discovered 14 compact, massive super star clusters (SSCs) still in formation. We present here ALMA data at 350 GHz with 28 mas (0.5 pc) resolution. We detect blueshifted absorption and redshifted emission (P-Cygni profiles) toward three of these SSCs in multiple lines, including CS 7-6 and (HCN)-C-13 4-3, which represent direct evidence for previously unobserved outflows. The mass contained in these outflows is a significant fraction of the cluster gas masses, which suggests we are witnessing a short but important phase. Further evidence of this is the finding of a molecular shell around the only SSC visible at near-IR wavelengths. We model the P-Cygni line profiles to constrain the outflow geometry, finding that the outflows must be nearly spherical. Through a comparison of the outflow properties with predictions from simulations, we find that none of the available mechanisms completely explains the observations, although dust-reprocessed radiation pressure and O star stellar winds are the most likely candidates. The observed outflows will have a very substantial effect on the clusters' evolution and star formation efficiency.
Author
Rebecca C. Levy
University of Maryland
Alberto D. Bolatto
University of Maryland
Adam K. Leroy
Ohio State University
Kimberly L. Emig
Leiden University
National Radio Astronomy Observatory
Mark Gorski
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Nico Krieger
Max Planck Society
Laura Lenkic
University of Maryland
David S. Meier
National Radio Astronomy Observatory Socorro
New Mexico Institute of Mining and Technology
Elisabeth A. C. Mills
University of Kansas
Juergen Ott
National Radio Astronomy Observatory Socorro
Erik Rosolowsky
University of Alberta
Elizabeth Tarantino
University of Maryland
Sylvain Veilleux
University of Maryland
Fabian Walter
Max Planck Society
National Radio Astronomy Observatory Socorro
Axel Weiss
Max Planck Society
Martin A. Zwaan
European Southern Observatory Santiago
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 912 1 4Subject Categories
Meteorology and Atmospheric Sciences
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
DOI
10.3847/1538-4357/abec84