Title: Intensity mapping with HIRAX and CHORD
Speaker: Prof. Cynthia Chiang (McGill University)
Date: May 30 at 11:00
Location: R521, General Building II
Abstract:
Radio measurements of the redshifted 21-cm emission line of neutral hydrogen enable three-dimensional reconstruction of large-scale structure in the universe. These measurements encode a faint imprint, known as baryon acoustic oscillations (BAOs), that correspond to remnant ripples left behind by sound waves echoing through the plasma of the early universe. These oscillations have a characteristic angular scale that serves as a "ruler" for measuring the universe's expansion history. Measurements from upcoming experiments will constrain BAOs with exquisite precision, opening new views into structure formation and shedding light on the mystery of dark energy. I will introduce two experiments, the Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) and the Canadian Hydrogen Observatory and Radio-transient Detector (CHORD), that have shared goals of measuring BAOs, searching for pulsars, detecting fast radio bursts and other transients, finding neutral hydrogen absorbers, measuring diffuse Galactic foreground emission, and other auxiliary science. The BAO cosmology goals impose unique and stringent constraints on the design of both instruments. I will discuss some of these challenges, as well as the status of both experiments and upcoming plans.
