Astrophysics & Planetary Sciences Colloquium

Abstract: I last came to CU in 2015, and talked almost entirely about molecules in galaxies.  Now I'm 8 years older, and 8 years more esoteric: 2023 Desika is going to talk all about dust!  But seriously, dust is awesome.  It impacts almost every astrophysical observation that you make, is a critical ingredient to thermal balance in the ISM, and is used to trace obscured star formation at all redshifts.   I'll present the results from a new model for dust in galaxy simula

Abstract: For the past decade we have begun to explore the origin of planetary compositions which are set in the natal protoplanetary disk.  

Abstract: Planetary atmospheres are not static in time, and the many changes they experience can contribute to making the planet’s surface a more (or less) hospitable place. Interactions between the planet and its host star are especially important, and not only control the temperature of an atmosphere but can drive atmospheric escape and atmospheric chemistry.

Abstract: In this talk, I discuss the interactions between stellar hosts and planetary companions, including the ejection and ingestion of stellar companions. Drawing insights from stellar evolutionary models and observational survey data (photometric and spectroscopic), I present my team's latest discoveries as we seek to identify unambiguous ingestion-derived chemical tracers.

NASA’s Double Asteroid Redirection Test (DART) mission, the first planetary defense test mission, deliberately impacted an asteroid in order to change its orbit. By impacting Dimorphos, the secondary member of the Didymos near-Earth asteroid binary system, on 2022 September 26, DART demonstrated asteroid deflection by kinetic impact as a technique that may someday be needed to protect the Earth from an asteroid impact threat. Months of subsequent Earth-based observations of the Didymos system showed that the DART impact changed the binary orbital period by –33 min.

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Abstract:  From the galaxy mergers that trigger new star formation and black hole growth, to the black hole mergers that produce gravitational waves, mergers are fundamental drivers of the evolution of our Universe. The first pulsar timing array observations of gravitational waves, which were announced earlier this year, offer a new opportunity to crack open the mysteries of how galaxy mergers lead to supermassive black hole mergers.

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Abstract: About half the light ever emitted by stars over the course of the history of the universe was absorbed by interstellar dust and re-radiated at long wavelengths. Dust-rich galaxies, extremely faint in visible light images, are the sites of intense starbursts that can rapidly assemble and then cut short the growth of the earliest generations of massive galaxies.