Marc Williamson

Marc Williamson

I am a PhD student at NYU studying the explosions of massive stars using radiative transfer modeling and observational studies of statistical samples of supernovae.

Posts by Collection

coauthorpubs

Near-infrared and Optical Observations of Type Ic SN 2020oi and Broad-lined Type Ic SN 2020bvc: Carbon Monoxide, Dust, and High-velocity Supernova Ejecta

Published in The Astrophysical Journal, 2021

We present NIR and optical spectroscopy of SN Ic 2020oi and SN Ic-bl 2020bvc. The NIR spectrum of SN2020oi shows clear CO emission and is the first such dust detection for an SN Ic. SN2020bvc exhibits extremely high ejecta velocities consistent with SN-GRBs despite the lack of observed GRB.

Recommended citation: Rho, Jeonghee; et al. (2021). https://ui.adsabs.harvard.edu/abs/2021ApJ...908..232R/abstract

Dalek: A Deep Learning Emulator for TARDIS

Published in The Astrophysical Journal Letters, 2021

We present DALEK, a neural network based emulator for the TARDIS radiative transfer code. DALEK can predict the output of TARDIS (synthetic spectra) to extremely high accuracy. A single DALEK evalution takes only milliseconds compared to thousands of seconds for a full TARDIS simulation, thus unlocking the ability to evaluate millions of TARDIS in mere hours.

Recommended citation: Kerzendorf, Wolfgang; et al. (2021). https://ui.adsabs.harvard.edu/abs/2021ApJ...910L..23K/abstract

The Exotic Type Ic Broad-lined Supernova SN 2018gep: Blurring the Line between Supernovae and Fast Optical Transients

Published in The Astrophysical Journal, 2021

We present optical and UV data on SN2018gep, a supernova that exhibited a fast rise with blue, featureless spectra until after peak light, when the spectra developed broad features typically seen in SNe Ic-bl. Significant blue excess flux is observed compared to other stripped SNe.

Recommended citation: Pritchard, Tyler; et al. (2021). https://ui.adsabs.harvard.edu/abs/2021ApJ...915..121P/abstract

Probabilistic Reconstruction of Type Ia Supernova SN 2002bo

Published in The Astrophysical Journal Letters, 2021

We present the first application of the DALEK emulator-assisted TARDIS modeling framework to fit models to the SN Ia 2002bo. Posterior distributions over model parameters like elemental abundances are produced and comparisons are made to hydrodynamical models of different types of SN Ia explosion mechanisms.

Recommended citation: OBrien, John; et al. (2021). https://ui.adsabs.harvard.edu/abs/2021ApJ...916L..14O/abstract

portfolio

publications

Optimal Classification and Outlier Detection for Stripped-envelope Core-collapse Supernovae

Published in The Astrophysical Journal, 2019

This paper presents the SESNPCA code, a public spectral classifier for stripped supernovae.

Recommended citation: Williamson, Marc, Maryam Modjaz, and Federica B. Bianco. "Optimal classification and outlier detection for stripped-envelope core-collapse supernovae." The Astrophysical Journal Letters 880.2 (2019): L22. https://ui.adsabs.harvard.edu/abs/2019ApJ...880L..22W/abstract

Modelling Type Ic Supernovae with TARDIS: Hidden Helium in SN 1994I?

Published in The Astrophysical Journal, 2021

This paper places an upper limit of 0.05 solar masses on the Helium content in the ejecta of stripped supernova 1994I using radiative transfer modeling.

Recommended citation: Williamson, Marc, Wolfgang Kerzendorf, and Maryam Modjaz. "Modeling Type Ic Supernovae with tardis: Hidden Helium in SN 1994I?." The Astrophysical Journal 908.2 (2021): 150. https://ui.adsabs.harvard.edu/abs/2021ApJ...908..150W/abstract

talks

teaching

Course Instructor PHYS 91SI–Practical Computing for Scientists

Undergraduate, Stanford University, 2014

As an undergraduate student, I was a course instructor for the student designed and taught course Physics 91SI. This was a for-credit course offered by the Stanford physics department and highly recommended by professors to undergraduates interested in joining their labs and beginning research. The curriculum of the course was a combination of programming and data science in order to give students the foundational skills to conduct research. My duties included syllabus design, lecturing, homework design, office hours, and mentoring for the final projects. The syllabus is archived here.

Graduate TA

Undergraduate & Graduate courses, New York University, 2016

During my PhD I was a TA for 5 courses at both the undergrad and graduate levels between 2016 and 2019:

  1. Introductory Electronics Laboratory (undergrad)
  2. Introductory Thermodynamics (undergrad, twice)
  3. Mathematical Methods for Physicists (undergrad)
  4. Computational Physics (graduate)

Each course required different management based on the student and instructor needs including experimental setup, homework design and solutions, exam design and solutions, supplemental lectures, and office hours.