3-12
Agata Karska
Nicolaus Copernicus University in Torun, Poland
co-authors: Ch. Fischer, M. Kazmierczak-Barthel (DSI), R. Klein (USRA), A. Belloche, C. König, F. Wyrowski (MPIfR), N. Le (NCU in Torun), A. Mirocha (Jagiellonian Univ., Cracow), M. Sewilo (NASA Goddard), W. Fischer (STScI), L. Kristensen (UCPH)
Outer Galaxy as a laboratory to study star formation across environments
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, 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 the 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. Thus, systematic surveys of star-forming regions in the outer Galaxy offer a unique opportunity to study the impact of the environment on star formation, and may bridge the gaps between the galactic and extragalactic star formation studies. Recent surveys with Spitzer and Herschel allowed the identification of distant galactic star forming regions, which can act as new laboratories to study star formation. Unbiased, systematic surveys are performed at submillimeter regime as part of the “Outer Galaxy High Resolution Survey” (OGHReS) survey at MPIfR in Bonn and "The Forgotten Quadrant Survey" ESO large program, and provide a full census of star-forming clumps up to galactocentric radii of ~17 kpc. A sensitive, efficient mapping instrument on SOFIA is necessary to characterize dust and gas cooling in these regions in the far-infrared, and build a coherent picture of the impact of the environment (e.g., metallicity) on star formation. FIFI-LS spectroscopy of the Gy 3-7 star-forming region in Canis Major will be used to illustrate the feasibility of the proposed studies and the challenges due to limited observing time on SOFIA and low spectral resolution.
