Circumnuclear Supernova Remnants and H II Regions in NGC 253

摘要: Archival VLA data have been used to produce arcsecond-resolution 6 and 20 cm images of the region surrounding nuclear 200 pc (~15'') starburst in NGC 253. Twenty-two discrete sources stronger than 0.4 mJy detected within ~2 kpc (~3') galaxy nucleus; almost all these must be associated with galaxy. None radio coincides a X-ray binary, so they appear due supernova remnants H II regions. The outside central has derived rate 0.1 yr-1 may account for at least 20% recent star formation Most newly identified steep, nonthermal spectra, but several relatively strong thermal also exist, containing equivalent tens O5 stars. These stars are spread over parsecs embedded regions having average ionized gas densities ~20–200 cm-3, much lower most active star-forming 253 or super–star clusters seen other galaxies. strongest emission highly reddened area near-infrared wavelengths, possibly optically obscured