EPoS Contribution
EPoS Contribution
3D space motions of molecular clouds and young stellar clusters with Gaia. A better understanding of the star formation history in the local Milky Way

Josefa Grossschedl
U Viena, Viena, AT
With Gaia we are now able to untangle the 3D structure and 3D dynamics of molecular clouds and young stellar clusters in star-forming complexes, allowing an improved reconstruction of the star formation history in the young solar neighborhood. Recently, we have examined the YSOs in the southern Orion complex with Gaia and radial velocity data. This study revealed coherent radial cloud motions at the 100-pc scale, indicating an expansion due to massive stellar feedback events in the past (see Fig.). This allowed, for the first time, to observationally quantify the influence of massive stellar feedback on these large scales, by analyzing the momenta of the clouds. In another recent study we show how the 6D phase space information of local star-forming regions helped us to better constrain the Local Bubble, which is a well known structure but not yet well characterized. Both results show that massive stellar feedback played (and plays) a crucial role in the regulation of star formation in the Milky Way. Such an improved understanding of local star formation events will also enable a better understanding for more distant star-forming regions in the Galaxy and beyond. This door to the "local truth" in 3D, as recently opened by Gaia, will further open with Gaia's future data releases.
Caption: 3D spaces motions of molecular clouds in the southern Orion complex. Shown are the cartesian positions of cloud parts, centred on the cluster Orion X (central red circle) at three time-steps. Shown are Orion A (blue), Orion B (magenta), and two cometary shaped outlying clouds (green). Additionally, the two young clusters sigma Ori and NGC1977 are shown in orange. The regions have been closest about 6 Myr ago and show an expanding motion on the 100-pc scale. (See an interactive version of the Figure here)
Collaborators:
J. Alves
C. Zucker


Suggested Session: Galactic Dynamics