Event Time: Thursday, October 28, 2021 | 4:00 pm - 5:00 pm
Event Location:
Hennings 201 (or via zoom)
Add to Calendar 2021-10-28T16:00:00 2021-10-28T17:00:00 First detection of cosmological signal with CHIME Event Information: CHIME will use Intensity Mapping of the 21cm line of neutral hydrogen to map large-scale structure between redshifts of 0.8 and 2.5. By measuring Baryon Acoustic Oscillations (BAO) we will place constraints on the dark energy  equation of state as it begins to dominate the expansion of the Universe, particularly at redshifts poorly probed by current BAO surveys. In this talk I will introduce CHIME, a transit radio interferometer designed specifically for this goal. I will discuss the promise and pitfalls of Intensity Mapping and describe how we plan to confront the many challenges of such observations, in particular removal of astrophysical foregrounds which are six orders of magnitude larger than the 21cm signal. Finally I will discuss our first intensity mapping science results: cross correlation measurements against eBOSS spectroscopic catalogs. This is the first detection of intensity mapping by an interferometer and the highest redshift measurements of large scale structure by 21cm. We have significant detections of all three tracers: LRGs, ELGs and quasars, and I will discuss the modelling and our interpretation of the results. Event Location: Hennings 201 (or via zoom)