Speaker
Description
Star formation is ubiquitous in the Galaxy, but the physical and chemical conditions in star-forming sites might differ as a function of galactocentric radius. Due to the negative metallicity gradient, the efficiency of gas cooling and dust shielding decreases in more distant regions. A lower interstellar radiation field and a decrease in cosmic-ray fluxes lead to a decrease in gas heating and ultimately cause lower gas and dust temperatures in the outer Galaxy. The balance between these processes sets the physical conditions of the gas and dust and likely affects star-formation rates and efficiencies. In this talk, we will present the first research highlights of the recently completed APEX legacy survey “Outer Galaxy High Resolution Survey” (OGHReS), which covers 100 deg^2 in the 3rd Galactic quadrant in the 2-1 transition of CO and its rare isotopologues. We will discuss important characteristics of the structure of the outer Galaxy, highlighting the differences with the inner Galaxy. We observed that large-scale filaments in the outer Galaxy are fundamentally quiescent objects, with a mass one order of magnitude lower compared to similar size filaments in the inner Galaxy. Additionally, outer galaxy filaments are found exclusively in inter-arm regions, which might point towards a different formation mechanism with respect to the inner Galaxy. The most prominent filament in the outer Galaxy, Falcor, is the only exception, being a site of efficient star formation and a host of the hot core candidate. Finally, we will present preliminary results of the follow-up studies of selected star-forming clumps in additional molecular and atomic lines, and discuss their gradients across the Milky Way. We will initiate the discussion to what extent the outer Galaxy can act as a laboratory of star formation in a low-metallicity environment, and propose the next steps necessary to interpret star formation in diverse ecosystems.
| What is your career stage? | Non-tenured scientist (post PhD) |
|---|---|
| Which telescopes do you use / are you affiliated with? | APEX |
