IAS/PU Joint Astrophysics Colloquium

Two Freaks and a Conundrum

David Jewitt
September 22, 2020
In the solar system as elsewhere, we learn most from the unexpected. I will describe three recent observational projects challenging existing ideas about solar system objects, and provoking new ones. The freaks are an interstellar object (‘Oumuamua) and a long-period comet (C/2017 K2), active far beyond Uranus. The conundrum concerns the origin of the Trojans of Neptune in the context of planetary migration.

Simulating Multiscale Astrophysics to Understand Galaxy formation

Rachel Somerville
Rutgers University; Flatiron Institute
September 15, 2020
Building genuinely a priori models of galaxy formation in a cosmological context is one of the grand challenges of modern astrophysics. Most large volume simulations of galaxy formation currently adopt phenomenological scaling relations to model "small scale" processes such as star formation, stellar feedback, and black hole formation, growth, and feedback, which limits their predictive power.

Near Field Star Formation: Surveying Young Stellar Objects and Young Stellar Clusters within 1 kpc of the Sun

Tom Megeath
University of Toledo
September 8, 2020
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.