Colloq Abstract - Jack Singal
May 06, 2022
11:00am Mountain
Jack Singal (University of Richmond)
How Bright is the Radio Sky? We Don't Know … Yet
Abstract
In astrophysics and cosmology many investigations depend on understanding the radio sky. These include studies of the cosmic microwave background and 21 cm cosmology, which must account for radio foregrounds which can be significantly brighter than the signals of interest. However the actual level of diffuse radio emission on our sky is surprisingly uncertain, and in fact all estimates ultimately trace back to just one measurement - the 408 MHz Haslam map from the 1980s, which itself derives its absolute calibration from highly uncertain measurements from the 1960s and earlier. This talk will discuss the present state of uncertainty, including the prospect of a bright, mysterious background of radio emission in the universe. Then we will discuss the current project to resolve these questions and make the first ever reliably absolutely calibrated large-scale radio map, using the unique features of the Green Bank Telescope combined with custom instrumentation.
