Seminar Date:
Friday, May 9th, 2014
Special Time:
3:15-4:15
Speaker:
Dr. Arielle Phillips
Research Faculty
Notre Dame Department of Physics & Astronomy
Title:
In the Neighborhood:
Of Galaxies, Nobel Laureates and Gummy Worms
Abstract:
We will journey from the cosmic web that envelops galaxies as they form, to a network of scientists that made a Nobel Prize winning discovery, and finally to the sinuous lengths of gummy worms to explore what they reveal about the very nature of light.
The formation, evolution, and chemical composition of galaxies are influenced by their interactions with the material immediately around them, or circumgalactic medium. Beyond this lies the intergalactic medium (IGM) which is composed of extensive clusters, filaments, and sheets of galaxies with vast empty expanses (voids) between them. We use a modified computer vision algorithm to identify and extract structures in large-scale simulations (clusters, filaments, voids.) Our understanding of the physical properties and extent of IGM structures leads to a clearer interpretation of their role in the evolution of galaxies and the surrounding circumgalactic medium.
Artistic representations of science tend to focus on the individual scientist with a marked preference for the single genius. The discovery of the accelerating universe, which involved two international teams, totaling fifty scientists, demonstrates how collaboration has become a central component of the scientific process. The High Z Project will give the public an insider’s perspective into the unusually non-hierarchical nature of the collaboration between the twenty scientists on the High Z Supernovae Search Team. Through a hybrid installation and performance, the audience will gain behind the scenes access to the the scientific quest, the collaboration, and the personal journeys behind the discovery of the accelerating universe.
Finally, I will touch on the extensive outreach efforts of physicists at Notre Dame and reveal how we use gummy worms to introduce children to spectra.
Seminar Date:
Friday, February 28, 2014
Special Time:
3:15-4:15
Speaker:
Dr. Kat Barger
NSF Postdoctoral Fellow
University of Notre Dame
Title:
Dislodged & Ionized: Gaseous Structures of the Magellanic Clouds
Abstract:
Galaxy evolution is governed by an intricate ballet of gaseous inflows and outflows and galaxy interactions. The nearby Magellanic Clouds provides an advantageous opportunity to study these processes in detail. In this talk, we will explore the gas flows associated with these galaxies through H-alpha emission- and UV absorption-line observations. Galaxy interactions have greatly disturbed the Magellanic Clouds and have tidally displaced massive amounts of gas from these galaxies. These interactions have also triggered intense star formation throughout their disks; we provide compelling evidence that this elevated star formation drives even more material from these galaxies in wide spread, feedback driven winds. Through these observations, we determine the properties of these gas flows and explore their fates. We find that over a billion solar masses of gas neutral and ionized gas surrounds these galaxies. Much of this dislodged gas is transferring between the Magellanic Clouds and the Milky Way, depleting and replenishing their star formation gas reservoir respectively.
Seminar Date:
Friday, May 23rd, 2014
3:15-4:15, Large Conference Room
Speaker:
Dr. Nick Cowan
CIERA - Northwestern University
Title:
Planetary Science from the Top-Down: the Exoplanet Opportunity
Abstract:
What started as a trickle in the mid 1990's is now a torrent, with over one thousand extrasolar planets currently known, and thousands of candidates awaiting confirmation. The study of exoplanets has already revolutionized our view of planet formation, and will soon do the same to our understanding of planetary atmospheres and interiors. The diversity of exoplanets gives us the leverage to crack hard problems in planetary science: cloud formation, atmospheric circulation, plate tectonics, etc. However, the characterization of exoplanets presents a challenge familiar to astronomers: our targets are so distant that we only see them as unresolved dots. I will describe how we can extract spatially-resolved snapshots of planets from such observations. These data are sufficient to constrain low-order climate models and therefore give us insight into the effects of clouds, heat transport, and geochemical cycling. Coarse measurements for a large number of planets is the perfect complement to the detailed measurements possible in the Solar System. That is the exoplanet opportunity.
Seminar Date:
Wednesday, March 12, 2014
Speaker:
Dr. Quinn Kanopacky
Dunlap Institute, Toronto
Title:
Orbits and Atmospheres of Directly Imaged Exoplanets
The first image of an extrasolar planetary system was obtained in 2008. Since then, there have been nearly a dozen gas giant planets directly imaged. These directly imaged exoplanets offer a new window into the rapidly evolving field of planet formation and evolution. The ability to separate the light of the planet from its host star is extremely advantageous for studying Jovian planetary atmospheres. The wide projected separations (~15 to 100 AU) of these planets provide insight into the orbital dynamics of long period objects. The combination of dynamical and atmospheric characterization can give clues about how these objects form and evolve. To demonstrate this new insight, I will discuss our team's results from an ongoing monitoring campaign of the HR 8799 directly imaged multi-planet system using the Keck Observatory adaptive optics system. High precision astrometry has provided constraints on the orbital properties of the four HR8799 planets. Moderate resolution spectroscopy has given precise estimates of the planets' effective temperature, surface gravity, and composition, leading to tantalizing clues about their formation. I will also discuss the successful first light runs of the Gemini Planet Imager (GPI), and instrument designed specifically to image and characterize young, widely separated Jovian planets. I will highlight some early results with GPI and describe the upcoming GPI Exoplanet Survey (GPIES), a three year campaign that will revolutionize our understanding of this fascinating planet population.
Seminar Date:
Monday, Jan 20th, 2014
Speaker:
Dr. Jenny Greene
Princeton University
Title:
To Build an Elliptical Galaxy
I discuss two essential aspects of elliptical galaxy formation: how they get their stars, and how they lose their gas. For the former, I use integral-field observations of local massive galaxies to study the stellar populations and kinematics of stars at large radius, to understand the origin of the size growth of elliptical galaxies.
Then I focus on black hole feedback as a means of clearing gas from massive galaxies. I show that luminous obscured quasars have ubiquitous, round ionized outflows with very high gas dispersions of nearly 1000 km/s out to 20 kpc.
Finally, if time permits I will combine these two themes and present our recent search for sub-pc supermassive black hole binaries.
Seminar Date:
November 7th, 2013
from 3:30-4:30 in the LCR
(Note the special date and time)
Speaker:
Dr. Jack Hewitt
NASA Goddard
Title:
Monsters of the Mid-plane: Galactic Accelerators in the Gamma-Ray Sky
Special Seminar Date:
Friday, October 4th, 2013
Special Seminar Time:
4pm.
Speaker:
Lindsay Grace
American University School of Communication
Title:
Alternative Play & Critical Gameplay
Abstract:
Dr. Grace will provide an overview of games as well as the movement toward alternative play and Critical Gameplay. For more details, visit his website or watch his recent presentation at Games for Change.
