MEASUREMENTS OF FLUX-DENSITY OF CAS-A AND CONFIRMATION OF AN ANOMALY AT 38 MHZ

Measurements of the flux density of the young SNR Cas A relative to that of CygA are presented at frequencies of 38, 151 and 1420MHz, and compared with recent observations by Erickson & Perley. Their report of an unexpectedly high flux density at 38 MHz is confirmed, and the two higher frequency results provide further evidence consistent with the suggestion of Baars & Hartsuijker that the radio spectrum of Cas A is tending to flatten. Some possible explanations of the 38-MHz result are discussed. © 1977 Royal Astronomical Society. Provided by the NASA Astrophysics Data System.