Wine and Cheese Spring 2019

This page records the schedule, titles and abstracts of the JHU/STScI CAS Astrophysics Wine & Cheese Series in Spring 2019.

Wine and Cheese sessions with one talk will have a 50 minute talk with 10 minutes for questions. Sessions with two speakers will have two 25 minute talks, each with 5 minutes for questions. Sessions in the Graduate Student Series will have three 15 minute talks, each with 5 minutes for questions.

February 4th

James Owen (Imperial College)

Understanding the formation and evolution of the Kepler Planets
The observed exoplanet population unveiled by Kepler is billions of years old, distinctly separated in time from the planet formation process that only lasted ~10-100 Myr. I will argue that atmospheric escape has been one of the key evolutionary drivers shaping the exoplanet population we observed today. By understanding how these planet evolve in time, I will show we can place some intriguing constraints on how they formed.

February 11th

Dillon Brout (UPenn)

First Cosmology Results Using Type Ia Supernova from the Dark Energy Survey
Today, now 20 years after the discovery of the acceleration of the universe, the Dark Energy Survey (DES) Supernova Program has discovered thousands of Type Ia Supernovae (SNe Ia) useful for cosmological measurements. In this talk I will present the first analysis of a small subset of 207 spectroscopically confirmed SNe Ia discovered during the first 3 years of the DES Supernova Program. I will show why this state of the art dataset provides constraints competitive to measurements using aggregate samples of >1000 SNe Ia, and I will forecast the full 5 year DES photometrically classified sample.

February 18th

TBD

Title
Abstract

February 25th

Paul Schecter (MIT)

Twinkling Quasars: a Strong Limit on the Contribution of LIGO-mass Primordial Black Holes to the Cosmological Dark Matter Density
On rare occasions, a galaxy acts as gravitational lens producing multiple images of a quasar directly behind it. The stars within this galaxy then act as micro-lenses, breaking up the "macro-images" into "micro-images". As the stars move, the macro-images twinkle -- the gravitational analog of atmospheric scintillation. Counterintuitively, the amplitude of the twinkling does not increase monotonically with stellar density, and instead decreases at high optical depth. A single strongly micro-lensed quasar can set a significant upper limit on the graininess of the gravitational potential. The poster-child for such a limit is SDSS0924+0219 for which at least 50% of the lens' surface mass density must be in a smooth component rather a than grainy one. A sample of ten lensed quasars gives a 10% upper limit on the contribution of LIGO-mass primordial black holes to the cosmological dark matter density after discounting the graininess due to the observed stars.