Past Work

In the 1D, neutrino-driven explosion paradigm, the final fate of a massive star, implosion or explosion, depends sensitively on its core structure immediately preceding core-collapse. Change the evolutionary history of a star, change its core structure. In Patton & Sukhbold (2020), we created a map between the structure of carbon-oxygen cores at carbon ignition and core-collapse using nearly 4,000 core models run in Kepler and MESA, revealing a complicated landscape of final structures and final fates. These models are agnostic of evolutionary history, thus widely applicable. 

In Patton, Sukhbold, & Eldridge (2022), we used single and binary BPASS models to show how the distribution of core properties of stars which had and had not experienced mass transfer and what the implications were for the initial mass distribution of compact objects. We also show how incorporating the core structure improves upon final fate prescriptions commonly adopted by binary population synthesis codes.

Current work

I am now working on the evolution of  high-mass stellar merger products, seeing how case B mergers change the core structure at carbon ignition and core-collapse and what the implications are for explodability.

Future work

The nucleosynthetic yields, properties of the resulting compact objects, and properties of supernovae themselves should all change as a result of binary interaction. In the future I would like to quantify those changes.

Past work

Stars born below the Kraft break should be slowly rotating as they become red giants due to magnetic braking and conservation of angular momentum. However, a few percent of these red giants rapidly rotate, likely due to spin-up from merging or tidal synchronization with a companion, stellar or planetary. Identifying rapid rotators usually requires a vsini measurement, but vsini is not included as a free parameter in spectroscopic fitting pipelines for large spectroscopic surveys, like ASPCAP for APOGEE, because it is low for the vast majority of red giants. 

In Patton et al. (2024) we developed a set of spectroscopic selection criteria to preferentially identify rapid rotators in APOGEE DR16. We confirmed rapid rotation at the 5 km/s threshold for over 1600 giants, the majority of which were in close binaries. We also discovered several failure modes of ASPCAP. The most surprising result was the surplus of giants with 5 < vsini < 10 km/s. There are 4x as many rapid rotators in that regime than with vsini > 10 km/s, which we means two things: there is a larger population of giants which have experienced some sort of binary interaction than previously thought and in the absence of other defining characteristics, the only way to find this population is by measuring vsini for all giants. 

Future work

Patton et al. (2024) and Pinsonneault et al. (2024) describe trends in vsini and binary fraction with evolutionary state and seismic properties, which allows us to piece together the typical evolutionary channels which produce these rapid rotators. This is a rich data, and there is a lot to be done, including probing activity, carrying out detailed studies of the single and binary rapid rotators, and identifying and characterizing sub-subgiants to name a few.