A Comparison of Discrete Sources in Radio and H surveys of the Magellanic Clouds - and the Potential for the New H Survey

Radio to H Comparison of the Sources towards the Small Magellanic Cloud

In the same manner as for the LMC, radio and H surveys of the SMC have been compared, resulting in the identification of 40 sources common to both surveys. Each radio source and H counterpart lie within 2.5'á of each other. This criterion was chosen according to the upper limit of positional uncertainties at our 1.42-GHz survey (Paperá V). Based on the common area of the two surveys and on the number of sources at each observing frequency (radio and H) we expect that not more than two sources will be found as a result of positional chance coincidence.

Positions for all 40 SMC sources common to the radio and H surveys have been compared in the same way as for the LMC. The mean differences are -5"9"á (radio-H) in RA with SD=51"á and -8"10"á in Dec with SD=65". This uncertainty is also consistent with the combined positional uncertainties for the radio (defined in Paperá V) and the H sources, and justifies the initial identification criteria of 2.5'á (which is equivalent to 2.7 in RA and 2.2 in Dec).

á© Copyright Astronomical Society of Australia 1997