10th Annual MKI Postdoctoral Symposium--Day 2 (speakers: Dave Principe, Shuo Zhang, Federico Marinacci)

Thursday, May 11, 11:45am
Marlar Lounge 37-252

10th Annual MKI Postdoctoral Symposium

Schedule for Thursday May 11th

Moderator: Allison Noble

11:45 - 12:00  Lunch catered by Sweet Ginger Thai

12:00 - 12:30  Dave Principe, “Observing the Circumstellar Environment of Eruptive Protostars with ALMA

Stars form as a result of gravitational contraction of rotating molecular clouds.  Observations of this stage of pre-main sequence (pre-MS) stellar evolution display large scale molecular outflows that act to transport energy back into the surrounding environment and are likely the main dispersing mechanism of molecular cloud material, responsible for the transition from a deeply embedded protostar with a circumstellar disk to the emergence of a pre-main sequence star with a planetary system.  I will present Atacama Large Millimeter Array (ALMA) 1.3 mm observations of several "FUor" type protostars, a class of young stellar objects identified by intense mass accretion events which cause extreme variability in the form of outbursts. These FUor type objects represent a brief stage of stellar evolution during which most of the stellar mass is accreted and is therefore essential to our understanding of how stars and planets form.  High spatial and spectral resolution observations of the circumstellar environment of these objects are essential to distinguish between different mechanisms capable of producing the observed accretion outbursts and to investigate the role these outbursts play in planet formation and early pre-MS stellar evolution.

12:35 - 1:05  Shuo Zhang, “Probing Cosmic-rays in the Central Galaxy”

The origin of Galactic cosmic-rays has remained one of the biggest puzzles in Astronomy for decades. The cosmic-ray population in the central Galaxy can be indirectly probed in the radio, X-ray and gamma-ray windows. A unique type of source in the Galactic center, the radio/X-ray magnetic filaments, may serve as good probes for GeV/TeV electrons. Meanwhile, the X-ray/gamma-ray emission from molecular clouds distributed on in the Galactic plane can put a tight constraint on the MeV-GeV, and even PeV cosmic-ray particles. In this talk, I am going to unfold the roles of the magnetic filaments and the molecular clouds in revealing the origin of cosmic-ray particles in the inner Galaxy. I will also introduce an exciting opportunity to put the first constraints on MeV-GeV cosmic-rays using the molecular cloud Sgr B2 in 2017.

1:10 - 1:40  Federico Marinacci, “Evolving magnetic fields with cosmological simulations”

Cosmological simulations represent the most complete approach to investigate the complex interplay among the physical processes that shape the evolution of the Universe. In my talk, I will highlight the tremendous progress made in this field by introducing a set of calculations with explicitly include a self-consistent treatment for the evolution of magnetic fields. I will mainly focus on the properties of magnetic fields in these simulations, and how they are affected by the inclusion of baryon physics processes that are thought to be relevant for galaxy formation. I will also discuss the potential effects of varying the magnetic seed field intensity on the properties of the simulated galaxy population. Finally, I will describe current developments on the future generation of cosmological MHD simulations.

2017 Postdoctoral Symposium Organizers: Rana Ezzeddine, Allison Noble, and DJ Pasham