The Corona Australis star formation complex is accelerating away from the Galactic plane

L. Posch, N. Miret-Roig, J. Alves, S. Ratzenböck, J. Großschedl, S. Meingast, C. Zucker, A. Burkert

We study the kinematics of the recently discovered Corona Australis (CrA) chain of clusters by examining the 3D space motion of its young stars using Gaia DR3 and APOGEE-2 data. While we observe linear expansion between the clusters in the Cartesian XY directions, the expansion along Z exhibits a curved pattern. To our knowledge, this is the first time such a nonlinear velocity-position relation has been observed for stellar clusters. We propose a scenario to explain our findings, in which the observed gradient is caused by stellar feedback, accelerating the gas away from the Galactic plane. A traceback analysis confirms that the CrA star formation complex was located near the central clusters of the Scorpius Centaurus (Sco-Cen) OB association 10-15 Myr ago. It contains massive stars and thus offers a natural source of feedback. Based on the velocity of the youngest unbound CrA cluster, we estimate that a median number of about two supernovae would have been sufficient to inject the present-day kinetic energy of the CrA molecular cloud. This number agrees with that of recent studies. The head-tail morphology of the CrA molecular cloud further supports the proposed feedback scenario, in which a feedback force pushed the primordial cloud from the Galactic north, leading to the current separation of 100 pc from the center of Sco-Cen. The formation of spatially and temporally well-defined star formation patterns, such as the CrA chain of clusters, is likely a common process in massive star-forming regions.

Department of Astrophysics, Research Network Data Science
External organisation(s)
Harvard-Smithsonian Center for Astrophysics, Universitäts-Sternwarte München, Max-Planck-Institut für extraterrestrische Physik
Astronomy & Astrophysics
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url