MATs (Monday Afternoon Talks)

3:00pm   Shreya Anand, California Institute of Technology

Testing whether Collapsars Synthesize r-process elements

Abstract: A rare sub-class of stripped envelope massive-star explosions, dubbed broad-lined Ic supernovae (SNe Ic-BL) have been highlighted as one of the potential sites of r-process nucleosynthesis capable of enriching our solar neighborhood with heavy elements. Here we present the first systematic study of 25 SNe Ic-BL in the optical and near-infrared bands to determine whether any r-process material is synthesized in these explosions. Using semi-analytic models designed to account for r-process production in SNe Ic-BL, as well as r-process free Arnett models, we perform light curve fitting to each SN. We find no compelling evidence of r-process production based on the model predictions. I will discuss the implications of our study as well as recommendations for future work.

Bio. I am a 5th year PhD candidate in physics at the California Institute of Technology, working with Professor Mansi Kasliwal on astrophysical sites of r-process nucleosynthesis. At Caltech, I am part of a small team of graduate students and postdocs in the Kasliwal group that conducts real-time wide-field searches for kilonovae associated with binary neutron star and neutron star–black hole mergers with the Zwicky Transient Facility.  I am excited to be involved in the rich science enabled by joint multi-messenger discoveries, especially as it relates to uncovering clues about heavy element production in the Universe. My interests also lie in developing machine-driven techniques to discover and characterize rare transients in upcoming large time-domain surveys like the Legacy Survey of Space and Time.

3:30pm  Dhayaa Anbajagane, University of Chicago

Going nonlinear with weak lensing surveys: Inflation, baryonic imprints, and other structure formation tales

Abstract: Widefield galaxy surveys are a powerhouse dataset for studying cosmology and astrophysics. These surveys were designed to probe the LCDM paradigm, but the data quality encourages many explorations of astrophysics as well as physics beyond LCDM. I will first discuss how measurements of weak gravitational lensing can probe the physics of inflation, with constraints that are both competitive and complimentary to those from other, more traditional probes. Achieving such constraints, however, necessitates more accurate models of the baryonic component of structure formation. I will describe our recent efforts in constructing halo-based, data-driven models for how baryons modify the phase space of the matter distribution, and also detail our ongoing efforts to propagate these effects to weak lensing observables, with the goal of placing tighter constraints on beyond-LCDM physics.

Bio. I am a 3rd year PhD student at the KICP, UChicago focusing on the physics of structure formation from both an observational and computational modeling perspective. I specialize in photometric surveys for weak lensing and am an active member of the DELVE and DES working groups. I am interested in studying beyond LCDM signatures with weak lensing, and in more accurately modeling the non-linear scales of structure formation with approximate galaxy formation models.

Host: Josh Borrow