The Images

A grey scale image of the whole survey is shown in Figure 1. To provide more detail of the sources, the mosaiced image has been divided into the fifteen smaller images presented in Figure 2. Each small image covers a  degree area with slight overlaps.

As explained earlier, the noise level is not constant across the mosaic image. It depends on the number and quality of the individual images which contribute to a given region. The rms noise is typically 0.5 mJy per beam area in the central areas and 1.5 mJy per beam area near the edge. The noise is not entirely random as can be seen in Figure 1. Some artifacts are still present at a low level; for instance elliptical grating rings (with an RA radius of 1.12) or other sidelobes of the strongest sources may not be completely removed. However these features are very weak and do not reduce the value of the images.

The mosaiced image contains no information on the broad features of the radio emission from the SMC because the MOST is an interferometer with a minimum separation of 42.9 wavelengths and so low spatial frequencies are attenuated or not recorded. The broad features of the SMC at 843 MHz measured with a beam of 24 arcmin are presented in Ye & Turtle (1991) which includes a separation into thermal and nonthermal components.

Catalogues including larger images of the relevant extended sources are in preparation separately for the SNRs, the H II regions and the background sources.

© Copyright Astronomical Society of Australia 1997