Authors: Andrew N O’Brien Miroslav D Filipović Evan J Crawford Nicholas F H Tothill Jordan D Collier Ain Y De Horta Graeme F Wong Danica Drašković Jeff L Payne Thomas G Pannuti Jared P Napier Stephen A Griffith Wayne D Staggs Srdjan Kotuš
Publish Date: 2013/05/29
Volume: 347, Issue: 1, Pages: 159-168
Abstract
A series of new radiocontinuum λ=20 13 6 and 3 cm mosaic images focused on the NGC 55 galactic system were produced using archived observational data from the Australia Telescope Compact Array These new images are both very sensitive down to rms=33 μJy and feature high angular resolution down to 4″ Using these newly created images 66 previously unidentified discrete sources are identified Of these sources 46 were classified as background sources 11 as H ii regions and 6 as supernova remnant candidates This relatively low number of SNR candidates detected coupled with the low number of large H ii regions is consistent with the estimated low star formation rate of the galaxy at 006 M ⊙ year−1 Our spectral index map shows that the core of galaxy appears to have a shallow spectral index between α=−02 and −04 This indicates that the core of the galaxy is a region of high thermal radiation outputThe National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities Inc The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO This paper includes archived data obtained through the Australia Telescope Online Archive http//atoaatnfcsiroau and the NRAO Science Data Archive http//archivenraoedu
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