EPoS Contribution
EPoS Contribution
Multi-episodic and triggered star formation in IC 1396 A: A Herschel surprise and IRAM followup of a newly formed object

Aurora Sicilia-Aguilar
U St Andrews, St Andrews, GB
IC 1396 A is a textbook example of a cometary-shaped bright-rimmed cloud at the edge of the IC 1396 HII region that surrounds the young Tr 37 cluster. After more than 40 years of studies in the optical and IR, and many young stars found within the globule, a proof of triggering by the expanding ionization front remained nevertheless elusive. And then Herschel came. Our Herschel/PACS program surprisingly revealed a new, highly-embedded, intermediate-mass Class 0 object just behind the ionization rim. The object is so embedded that it was not even detected in the deep Spitzer observations, and so compact that it could not be discerned from previously existing millimeter observations. The Herschel data show the star-forming history of IC 1396 A in a new light. Through the eyes of Herschel, IC 1396 appears as a diversified structure where several episodes of star formation have occurred within the last few Myr. IC 1396 A and Tr 37 are part of a cluster made of smaller, distinct structures or "mini-clusters" resulting from several episodes of star formation. Our new IRAM data reveal the dynamics at the tip of IC 1396 A and around the Class 0 source, showing how the formation of new stars proceeds in the globule, carving away the remaining parts of the dense molecular cloud. I will present our Herschel/PACS data and velocity-resolved IRAM molecular line observations, discussing the "mini-cluster" structure of the region, the dynamics of the star-formation process, and the connection between IC1396 A and Tr 37.
Caption: A multi-wavelength picture of the IC 1396 A globule. The location of the Class 0 object is marked with a pink box. The source (with its outflow) is only detected in the far-IR and longer wavelengths (Sicilia-Aguilar et al. 2013, 2014, 2015, 2016 in prep).
N. Patel, CfA, US
M. Fang, U Arizona, US
V. Roccatagliata, Munich Obs, DE
K. Getman, Penn. State U, US
Th. Henning, MPIA, DE
Key publication

Suggested Session: Cluster Formation