Insights into massive star explosions from infrared light

Samaporn (Kaew) Tinyanont (Caltech)
Friday, December 6, 2019 - 12:15pm to 1:00pm

The evolution and mass loss of a massive star prior to its death as a core-collapse supernova (CCSN) is a topic of active research. The diversity in observed properties of CCSNe points to different classes of massive stars exploding as different SN subtypes, but the identification of progenitor to most subtypes remain uncertain. New insights to solve this problem can be obtained by observing the SN interaction with its circumstellar medium (CSM), which have strong infrared (IR) emission signature. I will present recent results from IR observations of nearby CCSNe. First, I will discuss SN 2017eaw (II-P) in NGC 6946. IR imaging of its progenitor ruled out any major CSM ejections in the last year of its life. Yet, IR spectroscopy showed signs of interactions with nearby CSM, suggesting that the CSM is long-lasting. Second, I will discuss the unique strongly interacting SN 2014C, which transitioned from a H-poor Type Ib to an interacting, H-rich Type IIn about 100 days post-explosion. Imaging at 10-micron with Subaru/COMICS revealed the existence of silicate dust for the first time for an interacting SN, pointing to an O-rich CSM. The CSM properties obtained from fitting the IR light curve suggest a wind-driven CSM with high mass loss rate. I will discuss the implications on the progenitor system of this unique SN 2014C. These observations are preludes to what possible in the era of JWST.

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