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

Author(s)
L. Posch, N. Miret-Roig, J. Alves, S. Ratzenböck, J. Großschedl, S. Meingast, C. Zucker, A. Burkert
Abstract

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.

Organisation(s)
Department of Astrophysics, Research Network Data Science
External organisation(s)
Harvard-Smithsonian Center for Astrophysics, Universitäts-Sternwarte München, Max-Planck-Institut für extraterrestrische Physik
Journal
Astronomy & Astrophysics
Volume
679
No. of pages
11
ISSN
0004-6361
Publication date
11-2023
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/a4ce7f89-efce-4ffe-b1ba-6f26f9eb6a08