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TAPIR Seminar

Friday, April 28, 2023
2:00pm to 3:00pm
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Online and In-Person Event
New approaches to analyze optical transients
Tatsuya Matsumoto, Postdoctoral Fellow, Astrophysics Lab, Columbia University,

In person: 370 Cahill -- Attendees joining in person must have a valid Caltech UID.

To Join via Zoom: 864 8902 5566

ABSTRACT: The recent development of wide-field optical surveys has increased the number of optical transients at a surprising rate. In addition to traditional transients like supernovae (SNe), they have detected numerous novel and peculiar transients which have different luminosity and timescale than SNe. Given the optical surveys will be upgraded further in the near future, it is worth developing a new theoretical framework to analyze transients more quickly than conventional techniques. 

In this talk, I propose two new approaches to analyze optical transients. In the first part, I describe a novel method to estimate ejecta mass of optical transients. By using only bolometric light curves and time evolutions of blackbody temperature, this method is applicable to broader kinds of transients and gives more detailed information than the traditional Arnett rule. As an example, I discuss ejecta mass in optical tidal disruption events and give a constraint on the emission models.

In the second part, I focus on transients powered by shock interaction between ejecta and surrounding materials. I explain a new approach to estimate the density of the materials and apply it to recently observed double-peaked SNe.

For more information, please contact JoAnn Boyd by phone at 626-395-4280 or by email at joann@caltech.edu.