Rachel Friesen
University of Toronto

Abstract

Stars form within molecular clouds. Recent surveys of dust continuum emission of Galactic star-forming regions have shown that these clouds are highly filamentary. Dense molecular cores, the individual birth sites of stars, are largely embedded within these filaments. The star formation efficiency is thus strongly dependent on how these structures form and evolve, but continuum surveys alone cannot provide the kinematic data needed to investigate gas flows and stability. Here, I will present results from the Green Bank Ammonia Survey (GAS), a large program using the 100 m Green Bank Telescope, which provides this critical kinematic counterpoint to continuum surveys of nearby star-forming regions. GAS has mapped the major star-forming molecular clouds within 500 pc of the Sun in emission from ammonia (NH3) and other chemical species that preferentially trace cold, dense gas. With GAS, we are
1) evaluating the scales on which dense gas structures appear gravitationally stable,
2) tracking the dissipation of turbulence and the evolution of angular momentum from filaments to cores, and
3) quantitatively testing predictions of models of core and filament formation via mass flows and accretion.

Amy Furniss
California State University, East Bay

Abstract

Follow a gamma-ray photon from birth to death in a talk that is formatted for audience engagement!

Attendees will be able to choose the path of physics that the gamma-ray experiences as it makes its way from the depths of one of the most energetic galaxies in the universe to its eventual detection and study by patient Earthling scientists. Watch your step or you are likely to destroy the photon!

Catherine Espaillat
Boston University

Abstract

Dr. Arguelles Delgado
Harvard University

Abstract

Physics beyond the Standard Model is required to explain astrophysical observations (dark matter) and laboratory measurements (neutrino masses). In the neutrino sector, a persistent set of anomalies observed in short-baseline neutrino experiments point towards the existence of additional neutral fermions. These anomalies span a broad range of energy scales from MeV to GeV and appear in experiments that use different neutrino sources and detectors.

Many models that explain these anomalies introduce particles that mix with the known neutrino flavors. These “nu-friends” can produce signatures in high-energy neutrino experiments, such as the IceCube Neutrino Observatory near the geographic South Pole. This talk will review the efforts to search for them in IceCube.

Peter L. Galison
Harvard University

Abstract

In thousands of atlases depicting the working objects of inquiry—from bodies, clouds, plants, to crystals and insects-, physicians and natural philosophers worked out what counted as scientific objectivity.  This long-term history, with its various takes on what a reliable image should be, converged in the years-long struggle of the Event Horizon Telescope (EHT) to produce a picture of a black hole robust enough to make public.   On April 10, 2019, the team released the first image of a black hole, an image viewed within a very few days by more than a billion people.  This is a talk about how the EHT team of some 200 scientists came to judge the glowing, crescent-like ring as objective.