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Astrophysics Seminars


The CASS Astrophysics Seminar features world-class astrophysicists from around the world speaking on current topics of research. Presentations are aimed at the graduate and post-graduate level, but are open to the general public. CASS seminars take place on Wednesdays from 4:00 - 5:00 p.m. in 383 SERF (Marlar Seminar Room), unless otherwise noted. You can watch a live stream of the talk or prior talks at the CASS Seminar YouTube Channel. The organizers are Prof. Shelley Wright and Prof. George Fuller.

Upcoming Seminars

Winter 2017

March 15, 2017

 "The ISM of spiral galaxies seen in the FIR [CI] lines"

Alison Crocker
Assistant Professor
Reed College

 Neutral carbon exists sandwiched between the C+ and CO layers at a range of low extinctions heading into a molecular cloud. However, due to the inhomogeneous structure of turbulent molecular clouds, these low Av surfaces can exist nearly throughout a cloud, making it more likely that [CI] emission may be a good tracer of molecular gas within a cloud (Offner+ 14, Glover+ 15). I will discuss results on the observed [CI](1-0) and [CI](2-1) emission in 18 local spiral galaxies based on the Beyond the Peak survey using the Herschel SPIRE FTS spectrometer. The [CI](2-1) line is extremely well correlated with the CO(4-3) line, suggesting it traces more highly excited (warmer and/or denser) molecular gas than lower-J CO transitions. LVG modeling suggests this is a natural result from the similar excitation temperatures of the [CI](2-1) and CO(4-3) lines. I’ll finish by discussion the use of an “alpha-CI” factor to convert [CI] line emission to a molecular gas mass.

Spring 2017

March 29, 2017

Mike Norman
Professor of Physics, CASS; Director of San Diego Supercomputer Center

April 5, 2017

Amanda Weltman
South African Research Chair in Physical Cosmology and Head, Cosmology and Gravity Group,
Deptartment of Mathematics and Applied Mathematics
University of Cape Town, South Africa

April 19, 2017

Mitch Begelman
Professor, Department of Astrophysical & Planetary Sciences
University of Colorado, Boulder

April 26, 2017

Alex Lazarian
University of Wisconsin-Madison

May 3, 2017

Rychard Bouwens
Associate Professor
Leiden Observatories

May 10, 2017

Wladimir Lyra
Assistant Professor, Department of Physics & Astronomy
California State University at Northridge (CSUN)

May 17, 2017

 "The Dynamics of the Local Group: Challenges to Convention in the Era
of Precision Astrometry"

Gurtina Besla
Assistant Professor
University of Arizona

 Our understanding of the dynamics of our Local Group of galaxies has changed dramatically over the past few years owing to significant advancements in astrometry and our theoretical understanding of galaxy structure. I will provide an overview of key contributions by the Hubble Space Telescope to this evolving picture. In particular, I will highlight the HSTPROMO team’s proper motion measurements of key players in the Local Group, such as the most massive satellites of the Milky Way (the Large and Small Magellanic Clouds), the first ever direct proper motion measurement of M31 and an implied new orbital history for M33. These results have met with controversy, challenging preconceptions of the orbital dynamics and evolution of key members of the Local Group. I will further highlight the importance of HST’s continued role in this field in the era of Gaia.

May 24, 2017

Max Millar-Blanchaer
Millikan Postdoctoral Fellow

May 31, 2017

Robyn Sanderson
NSF Astronomy & Astrophysics Postdoctoral Fellow
TAPIR, Caltech / Columbia University Dept of Astronomy