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3/1/18: SO/NOAO Joint Colloquium Series: Rachel Friesen, NRAO


Title: The Green Bank Ammonia Survey: Probing the Evolution of Star-Forming Regions from Filaments to Cores

The conversion of gas into stars is a key process driving the evolution of observable structures in the universe. Recent surveys of dust continuum emission of Galactic star-forming regions have revealed the ubiquity of high column density filamentary structures within molecular clouds, raising the tantalizing possibility that the star formation efficiency is strongly dependent on how these dense structures form and evolve. I will show how the combined analysis of gas dynamics and chemistry in star-forming regions is essential for understanding mass accretion onto molecular filaments, and the stability and fragmentation of filaments and embedded star-forming dense cores. Large-scale molecular line surveys are thus sorely needed. In particular, I will present science results from the Green Bank Ammonia Survey (GAS; co-PI), in which we have mapped the dense molecular gas of all the major star-forming molecular clouds within 500 pc with the GBT.