2002/05/27 by Ian R. Stevens, I. R. Stevens, Duncan A. Forbes +3 · 10 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Dwarf galaxy #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Radio Astronomy Observations and Technology #Radio galaxy #Spectral index #Star cluster #Star formation #Supernova #Telescope #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2002.05696.x
published in Monthly Notices of the Royal Astronomical Society 335(4), 1079-1084 (Oxford University Press) · Accepted for publication in MNRAS
arxiv created 2002/05/27 · openalex publication_date 2002/10/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present new radio continuum observations of two dwarf starburst galaxies, NGC 3125 and 5408, with observations at 4.80 GHz (6 cm) and 8.64 GHz (3 cm), taken with the Australia Telescope Compact Array (ATCA). Both galaxies show a complex radio morphology with several emission regions, mostly coincident with massive young star clusters. The radio spectral indices of these regions are negative (with α∼−0.5 to −0.7), indicating that the radio emission is dominated by synchrotron emission associated with supernova activity from the starburst. One emission region in NGC 5408 has a flatter index (α∼−0.1) indicative of optically thin free–free emission, which could indicate it is a younger cluster. Consequently, in these galaxies we do not see regions with the characteristic positive spectral index indicative of optically obscured star formation regions, as seen in other dwarf starbursts such as Hen 2–10.