2015ApJ...798...36S

We report observations of warm carbon chain chemistry (WCCC) in NGC 3576, including high angular resolution imaging of an ionization source candidate and the first detection of C₅ H in a massive star-forming region. In order to investigate the environment associated with birthline emergence, we ask how observed chemical conditions relate to Class 0/1 core differentiation: a systemic shift in peak position between species correlates with giant molecular cloud core gradients in turbulence and age. Emission in several molecular lines including HC₃N (11-10), NH₃(1, 1), and C₅H supports the G291.3-0.7 ionization front–transitional pre-main-sequence core interaction regulating the WCCC environment.