Gravity Group Astrophysics|Cosmology Lunch "Detecting the Epoch of Reionization and Characterizing the Properties of the First Galaxies"
(More about event)Speaker: James Aguirre, University of Pennsylvania
Abstract: Between the last scattering of the CMB at 400 kyr after the Big Bang to the appearance of the first quasars at around 900 Myr after the Bang, we have precious little direct observational evidence for the formation process of stars and galaxies. During this period, however, the first stars and galaxies are known to produce enough ionizing radiation to completely ionize the initially neutral intergalactic medium. It is thought that the galaxies primarily responsible for reionization are intrinsically low-luminosity, and characterizing their properties will be challenging, even for JWST and ALMA. I will discuss current efforts to detect the reionization epoch using the Precision Array for Probing the Epoch of Reionization (PAPER). PAPER is a focused experiment comprising an array of 128 dual-polarization antennae operating from 100 – 200 MHz to detect the redshifted signal from the hyperfine 21 cm transition of neutral hydrogen. PAPER employs a unique strategy for optimizing its sensitivity to the power spectrum of fluctuations. I will discuss the instrument and observing strategy and summarize the current state. I will also discuss some ideas being explored to extend the idea of “intensity mapping” to far-infrared fine structure lines to gain insight into the interstellar medium of the first galaxies, and thus characterize the process of some of the earliest star formation.
I will discuss the PAPER experiment and some recent results
Location: Joseph Henry Room
Date/Time: 03/23/12 at 12:00 pm - 03/23/12 at 1:30 pm
Category: Gravity Group Seminar
Department: Physics