From The Solar Neighborhood To The Cosmic Dawn: Prospects In Radio Astronomy

Dr. Harish Vedantham (hosted by Cowsik/Ogilvie), California Institute of Technology
February 22, 2017 at 4:00 pm
204 Crow
Event Description 

Radio astronomy is currently undergoing a renaissance. At low radio frequencies (30 to 200 MHz), a new generation of telescopes such as LOFAR, MWA and PAPER are now operational. A primary motivation for these telescopes is the study of the Epoch of Reionization (EoR)--- an unexplored epoch in the infant Universe (first ~ billion years) where the first bound objects (stars, galaxies etc.) formed. In this talk, I will discuss the challenges and preliminary results from the LOFAR-EoR project. The anticipated faintness of the EoR signal has lead the project towards building an exquisite understanding of Galactic and extragalactic foreground emission which itself is yielding interesting auxiliary science. I will discuss one such example--- the discovery of mysterious over-dense plasma structures in the local interstellar medium. At higher frequencies (1-100 GHz), large-scale transient/variability surveys are finally attaining maturity. I will discuss the recent discovery of new form of radio variability in extragalactic sources that are likely caused by gravitational lensing by intervening intermediate-mass objects (103 - 106 solar masses), and prospects to constrain the fraction of cosmic-matter in this mass regime with upcoming facilities such as the next generation VLA (ngVLA).

Coffee: 3:30 pm, 245 Compton