Radio Images of 3C 58: Expansion and Motion of Its Wisp

摘要: New 1.4 GHz VLA observations of the pulsar-powered supernova remnant 3C 58 have resulted in highest quality radio images this object to date. The show filamentary structure over body nebula. present were combined with earlier ones from 1984 and 1991 investigate variability emission on a variety timescales. No significant changes are seen 110 day interval. In particular, upper limit apparent projected velocity wisp is 0.05c. expansion rate nebula was determined between 2004 0.014% ± 0.003% yr-1, corresponding 630 70 km s-1 along major axis. If SN 1181, it must been strongly decelerated, which unlikely given absence shell. Alternatively, low speed number other arguments suggest that may be several thousand years old not 1181.