Towards a complete picture of the Sco-Cen outflow

Author(s)
M. Piecka, S. Hutschenreuter, J. Alves
Abstract

Previous studies have presented strong evidence that the Sun is crossing an outflow originating from the Scorpius-Centaurus OB association (Sco-Cen). Understanding this outflow's origin and structure illuminates how massive star formation shapes the interstellar medium (ISM) and helps predict future Galactic conditions that will affect our Solar System. We analysed H I emission and optical ISM absorption lines towards 47 early-type stars around the Upper Sco region to refine the map of the Sco-Cen outflow. Combined with data for nearby stars, we find that the outflow has at least two components: a faster, low-density component traced by Ca II, and a slower, possibly lower-density component traced by Mg II and Fe II in the UV that is passing through the Earth. A constant flow model successfully describes both components with (l, b, |v|) = (335.4, -6.8, 14.0 km s

-1) and (305.5, +17.6, 21.2 km s

-1), respectively. The origin of the faster component is possibly related to the Sco-Cen 15 Myr population, which is consistent with the origin of the slower component within 2 σ. A simple model comparison indicates that a constant flow is favoured over a spherical flow geometry, implying an extended distribution of feedback sources within Sco-Cen. We also find that a poorly studied 25 pc long H I cloud at a distance of 107 pc belongs to the established Sco-Cen flow.

Organisation(s)
Department of Astrophysics, Research Network Data Science
Journal
Astronomy & Astrophysics
Volume
689
No. of pages
11
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361/202450936
Publication date
09-2024
Peer reviewed
Yes
Austrian Fields of Science 2012
103004 Astrophysics, 103003 Astronomy
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/f86f171b-8bf2-4b60-a91a-8a5ed4c3b8fb