A sample of 113 compact radio continuum sources has been detected in and behind the LMC at 1.4 GHz with the Australia Telescope Compact Array (ATCA); 70 objects have been found at 2.4 GHz. The sample is almost complete down to a flux density limit of about 6 mJy at 1.4 GHz for sources smaller than and about 3 mJy at 2.4 GHz for (see Table 1 (click here)). As the sizes of the sources are smaller than 13 pc at 1.4 GHz and 8 pc at 2.4 GHz the objects are either extragalactic background sources or compact objects within the LMC, such as compact HII regions or young SNRs. The vast majority of our sources have been seen for the first time. This is due to the higher angular resolution of the ATCA compared to the instruments used for previous surveys.
Excluding the 15 sources which are located in the regions of H objects in the Davies et al. (1976) catalogue and which have flux densities in the range plus three known HII regions, we find that our source counts agree very well with those of Oosterbaan (1978). So we conclude that our catalogue of compact sources contains beyond the 3 known HII regions located in the area only about 15 objects which are probably intrinsic to the LMC. More detailed observations of sources within the boundary of DEM objects will be presented in a subsequent paper.
We thank the staff of the ATCA for their assistance and advice. We are grateful for the hospitality of the ATCA at Narrabri and Epping during our visit. We thank the members of the Graduiertenkolleg in Bonn/Bochum for very useful discussions. Thanks are especially due to Uwe Herbstmeier for valuable suggestions and information. Jürgen Osterberg and Eva Grebel are thanked for providing us with data for comparisons. The research of M. Marx was supported by the Cusanuswerk (Bonn, Germany), U. Mebold was supported by the Deutsche Forschungsgemeinschaft under grant Me745/16-1. J. Dickey was supported in part by National Science Foundation grants 87-22990 and 92-22130 to the University of Minnesota, by a grant from the NSF Unique Foreign Telescope Fund supervised by the National Radio Astronomy Observatory, and by the Office of International Programs at the University of Minnesota.