Northwestern University

Wed 12:00 PM

Professor Eric Wilcots: Searching for Missing Baryons and the Cosmic Web at Radio Wavelengths

When: Wednesday, February 7, 2018
12:00 PM - 1:00 PM  

Where: Technological Institute, F160, 2145 Sheridan Road, Evanston, IL 60208 map it

Audience: Faculty/Staff - Student - Public - Post Docs/Docs - Graduate Students

Contact: Yassaman Shemirani   847.491.7650

Group: Physics and Astronomy Radio Astronomy Seminars

Category: Academic


Title: "Searching for Missing Baryons and the Cosmic Web at Radio Wavelengths"

Speaker: Professor Eric Wilcots, University of Wisconsin

Abstract: We now understand that a significant amount, if not most, of the baryonic matter in the Universe resides in what is broadly considered to be the intergalactic medium (IGM). While some of this matter likely exists in the immediate environment of individual galaxies in what is known as the circumgalactic medium (CGM), much of it is thought to fill a “cosmic web” that forms the large-scale structure of the Universe. Given that a large portion of the CGM and IGM is very diffuse and thus difficult to measure in emission at any wavelength, many observational studies have focused primarily on detecting this gas in absorption, using absorption lines of a variety of ions to probe different gas regimes in the ultraviolet part of the spectrum. We are taking a different approach, probing this important component of the baryonic content of the Universe using radio telescopes. In this talk, I will show how we can use observations of radio galaxies to derive densities of the intergalactic medium of 10^-4 - 10^-3 cm ^-3; high enough to account for the missing baryons in these systems and have a dramatic impact on the evolution of resident galaxies. We are also using deep radio continuum observations to detect the presence of large-­scale intergalactic magnetic fields. Lastly, I will discuss how the new generation of radio observations with sufficiently long integration times and high sensitivities offer the ability to probe neutral hydrogen in absorption in the intergalactic medium.

Host: Zadeh

Speaker Schedule

Keywords: Physics, Astronomy, Radio Astronomy 

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