Events: Colloquia

A&A Colloquium: Damiano Caprioli (University of Chicago)

3:30–4:30 pm Zoom - Please contact Laticia at lrebeles@oddjob.uchicago.edu for info

The Non-thermal Universe

Non-thermal particles are ubiquitous in the Universe: we can detect them at Earth as cosmic rays, probe them in-situ with spacecraft in the heliosphere, and observe their emission from galactic and extra-galactic objects over a vast range of frequencies spanning from radio to gamma-rays. I present some paradigmatic examples of how ab-initio plasma simulations can be used to further our understanding of particle acceleration and transport, and eventually the non-thermal phenomenology of several astrophysical objects. Moreover, I illustrate how cosmic rays and magnetic fields can play a crucial role in the interstellar medium and hence in galactic dynamics and evolution.

Jan 19

A&A Colloquium: Carlos Vargas (University of Arizona)

3:30–4:30 pm TBD

Why I Stopped Waiting for Someone Else to Map the Warm-hot Circumgalactic Medium

For over half a century, observational astrophysics has been eager to successfully detect and map the most massive baryonic component of galaxies: warm-hot phase coronal gas extending into the circumgalactic medium (CGM). Despite its importance to galaxy evolution, this phase of gas is entirely unmapped in the nearby universe. Morphological characteristics, such as the presence, size, and extent of filamentary or cloud-like structures, are impossible to determine through pencil-beam absorption line studies. The evolution of galaxies relies heavily on the properties of gaseous halos, indicating an urgent need to map and measure these
understudied regions. In the last decade, high-efficiency reflective coatings for UV optics have experienced improvements in reflectivity per bounce and overall coating stability in the far UV (FUV). Detector technology sensitive to FUV wavelengths has seen steady development of Microchannel Plate (MCP) detector technology. In parallel with these advances in UV technology, SmallSat missions with serious science objectives—which did not exist a decade ago—have emerged as a promising platform for high-impact science, an opportunity for more adventurous experiments and investigations. In this talk, I present Aspera (PI C. Vargas): a FUV SmallSat mission to detect and map warm-hot phase gas emission in nearby galaxies for the first time. The Aspera mission is designed to target the O VI emission line doublet from highly ionized oxygen, located at ll=1032, 1038 Å rest frame. Aspera combines a simple spectroscopic optical design using advances in highly-reflective FUV-coated optics with advanced UV MCP detectors to optimize throughput and sensitivity. Aspera will build multiple days of exposure time on each individual target to ensure spectroscopic detection of O VI emission and produce 2D morphological maps and direct measurements of physical conditions such as kinematics. The Aspera mission was selected for funding in the inaugural 2020 NASA Astrophysics Pioneers Program ($20M) in January of 2021.

Feb 2
Mar 2