Institute for Advanced Study / Princeton University Joint Astrophysics Colloquium

Surveys of young stellar objects (YSOs) populating nearby molecular clouds are bringing us closer to an integrated picture of star and cluster formation, one that incorporates processes spanning many orders of magnitude in size, from accretion on stellar scales to the formation of clusters and associations on molecular cloud scales. Following a spectacular 15 years of infrared astronomy with Spitzer and Herschel, we now have a nearly compete census of the dusty YSOs (those with disks or infalling envelopes) in the clouds within 500 pc of the Sun. These data have enabled follow up studies with ALMA, VLA, HST and SOFIA. Focusing primarily on studies of the Orion molecular clouds, this talk will introduce the emerging pieces of the puzzle that are leading to a comprehensive picture of low to intermediate mass star formation. We start with observations of the evolution of protostars, including the detection of very young protostars within 10,000 years of their formation, the determination of the rate of accretion outbursts for protostars, and measurements of the role of mechanical feedback in halting mass accretion. We then discuss the use of low mass YSOs as tracers of star formation on cluster and cloud scales, resulting in the discovery of star formation laws in nearby clouds and providing clues as to how embedded clusters may survive gas dispersal to form bound open clusters.