An Extragalactic Radio Background?
07 Jan 2009 – The ARCADE experiment reported ( NYT, Science News, GSFC press release) the existence of an extragalactic radio background. But this signal has the same spectrum as the radio emission from the Milky Way, and could well be due to an error in determining the galactic contribution to the total signal. The papers are available here, here, here and here. The ARCADE data are beautiful but mainly cover higher frequencies where the extragalactic radio background is not detectable, so the “ERB” depends on a debatable assumption about the lower frequency data, which are all tied to the Haslam 408 Mhz map, published in 1981, but with a zero point set using Pauliny-Toth & Shakeshaft, published in 1962! Pauliny-Toth & Shakeshaft certainly did not see an ERB or even the CMB in their data. A Bigger Milky Way 05 Jan 2009 – Mark Reid reported at the AAS meeting on very precise distances to radio masers that have led to an increase in the estimated size and rotation velocity of the Milky W
