Cosmology Seminar

Cosmology Seminars are held on Mondays at 11 am, on the 3rd floor Varian conference room. These are more focused and less didactic than the colloquium, and provide a stage for younger researchers to present their work in more detail.  

Please contact Simon Birrer, Nick Kokron or Risa Wechsler for more information.

Stellar streams in the deforming dark matter haloes of the Milky Way and the LMC

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Location

Campus, Varian 355

Speaker
Sophia Lilleengen (University of Surrey) In Person Only

The ongoing merger of the Milky Way and the Large Magellanic Cloud (LMC) is deforming the dark matter haloes of both galaxies, effectively making these galaxies a local dark matter collider. With stellar streams being sensitive to the gravitational potential, the Orphan-Chenab (OC) stream is particularly insightful as it spans the inner and outer Milky Way, and it passes close to the LMC. I will present the first models of the OC stream in time-dependent halos of the Milky Way and the LMC that are described by basis function expansions of N-body simulations of the Milky Way-LMC passage.

Precision Cosmology: from CMB and 21cm

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Location

Campus, Varian 355

Speaker
Zhilei Xu (MIT) In Person

Over the past decades, observations of the cosmic microwave background (CMB) have established the standard cosmological model. In the future, 21cm signals from neutral hydrogen have great potential for cosmological and astrophysical studies. In this talk, I will review the previous CMB observations and how it established the ΛCDM cosmology model. Then I will discuss the instrumentation and calibration of the Cosmology Large Angular Scale Surveyor (CLASS) and the Simons Observatory (SO).

Probes of galaxy interactions: from the Magellanic Stream to lensed supernovae

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Location

Campus, Varian 355

Speaker
Peter Craig (Rochester Institute of Technology) In Person

We have been working on a variety of projects, which are generally connected by trying to understand the distributions of dark matter. First, we used hydrodynamic simulations of the Magellanic Stream to estimate the mass of the MW potential. The simulated streams are sensitive to the MW potential because the potential determines the orbits of the satellites. The orbits determine the strength of the tidal interactions and ram pressure stripping in the simulations that cause stream formation.

Cosmology and astrophysics with the extragalactic light: background and fluctuations

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Location

Campus, Varian 355

Speaker
Gabriela Sato-Polito (Johns Hopkins University) In Person

The aggregate light emitted by all extragalactic sources can be measured either as an absolute intensity or through its spatial fluctuations; these are known as line-intensity mapping (LIM) when a particular line transition is targeted. I will discuss how these measurements can be used both to learn about galaxy evolution and to investigate the presence of more speculative sources of radiation, such as decaying dark matter.