Speaker
Description
Massive star formation is thought to occur within the Galactic disk, so the presence of massive stars at a Galactic height of more than a kiloparsec is unexpected given their short lifetime. Using the Alma Luminous Star (ALS) III catalogue (Pantaleoni González et al. 2025) and Gaia DR3 data, we determined the scale height of Galactic OB candidate stars (64±4 pc) and identified 90 luminous objects at a Galactic height exceeding 750 pc, up to a height of 2 kpc. We term these objects eXtreme Galactic Latitudinal Objects (XGLOs). Based on their current position and velocity (if available including the radial velocity), and taking into account the Galactic potential, we reconstructed their paths to find out whether these objects could have originated from the Galactic plane within their estimated lifetime. We find that all XGLOs left the Galactic plane within a timeframe of 5 - 60 Myr; three of them seem to originate from the Galactic center. Our hypothesis is that these XGLOs are OB runaways that were born in the Galactic plane and were ejected by dynamical interactions within their parent cluster or with the supermassive black hole Sgr A*.
| Talk category | NOVA Network 2 |
|---|---|
| Second preference | NOVA Network 3 |
