MSI and Astro seminars are held on Tuesdays at 3:30 pm on alternating weeks during the fall and winter semesters.
Astro Seminars: feature speakers who discuss topics in astronomy, astrophysics and cosmology. Seminars will be held in the R.E. Bell Conference Room (room 103) in the Rutherford Physics Building.
MSI Seminars: feature speakers who discuss topics in astrophysics, planetary science, atmospheric science and astrobiology. Most seminars are held in the MSI conference room at 3550 University. Some seminars are held in the R.E. Bell Conference Room (room 103) in the Rutherford Physics Building (to accommodate larger audiences).
McGill Space Institute
Stars freeze. As they age and cool white dwarfs and neutron stars crystallize, with remarkable materials forming in their interiors. These 'astromaterials' have structures similar to terrestrial crystalline solids and liquid crystals, though they are over a trillion times denser. Notably, because their material properties affect the observable properties of the star, astromaterials must be understood to interpret observations of neutron stars. Thus, astromaterial science can be thought of as an interdisciplinary field, using techniques from material science to study nuclear physics systems with astrophysical relevance. In this talk, I will discuss recent results from simulations of astromaterials and how we use these results to interpret observations of neutron stars in X-ray binaries.
The most recent generations of large-volume cosmological hydrodynamical simulations are valuable instruments for understanding the formation and evolution of galaxies. However, the crux of the interpretive power for such simulations is fundamentally in whether they can reproduce the observed properties of galaxies. Furthermore, it is crucial that any comparison between simulated and real galaxies is fair. To facilitate a valid comparison, simulated galaxies must adopt the observational biases that affect galaxies seen in the real Universe. I put galaxies from the Illustris simulation directly in the context of observational galaxy astronomy using an unprecedentedly rigorous suite of observational realism in the Sloan Digital Sky Survey (SDSS). Parametric photometry and structural analysis of simulated galaxies with observational realism are performed using the same pipeline that was used in the analysis of 1.12 million real galaxies in the SDSS — which collectively forms the comparison sample. In this talk, I will discuss promising similarities along with intriguing contrasts between real and simulated galaxy populations. With major Intregral Field Spectroscopic surveys such as SAMI and MaNGA defining new frontiers in observational galaxy astronomy, the completeness with which simulated galaxies may be benchmarked against observations has never been better.
The Cosmology Large Angular Scale Surveyor (CLASS) is a four telescope array designed to detect and characterize relic primordial gravitational waves from inflation and the optical depth to reionization through a measurement of the polarized cosmic microwave background (CMB) on large angular scales. The frequency bands of the CLASS telescopes, one at 40 GHz, two at 90 GHz, and one dichroic system at 150/220 GHz, are chosen to avoid regions of high atmospheric emission and span the minimum of the polarized galactic foregrounds: synchrotron emission at lower frequencies and polarized dust emission and higher frequencies. Low noise transition edge sensor detectors and a rapid front-end polarization modulator provide a unique level of high sensitivity, stability, and control of systematics. The CLASS site, at high altitude in the Chilean Atacama desert, allows for daily mapping of up to 70% of the sky and enables the observation of the largest angular scales. Using this combination of a broad frequency range, large sky coverage, control over systematics, and high sensitivity, CLASS will observe the reionization and recombination peaks of the CMB E- and B-mode power spectra. CLASS will make a cosmic variance limited measurement of the optical depth to reionization and will measure or place upper limits on the tensor-to-scalar ratio, r, down to a level of 0.01 (95% C.L.).
Weizmann Institute of Science
The Juno spacecraft has been in orbit around Jupiter since July 2016. In this talk we will review the mission and the preliminary results from its first year. Particularly we will focus on the Juno gravity experiment, which has revealed the depth and vertical structure of Jupiter’s atmospheric dynamics and interior flows.
University of Western Ontario
Planetary formation and evolution during the first 500 millions years of the Solar System’s history can be deciphered through the study of meteorites and samples returned from space missions as well as from remote observations. By studying meteorites, we have found evidence that several short-lived radiogenic isotopes were present initially in the early Solar System and are now extinct. Some of them like 26-Al contributed to the internal heating of planetesimals and hence their ability to melt as well as setting their budgets in volatile elements delivered to planets. Other refractory elements can be used as tracers for the building blocks, late accretion, and constraining the timing of volatile element delivery within the terrestrial planets. I will talk about our current knowledge of the nucleosynthetic heritage of the Solar System, how we can use isotopes as tracers and chronometers of planetary formation, and how major planetary impact events have influenced the evolution of our planet and set the geological conditions for life to develop.