D. J. Thorne

Multiwavelength isophotal data for southern elliptical galaxies

Isophotal profiles are presented for 40 southern elliptical galaxies derived from CCD imaging with B, V, R, I, and Gunn z filters. The data show excellent agreement with other CCD observations. The principal use of these data will be to search for wavelength dependences of isophotal parameters

A CCD image of the galactic centre

Because the galactic centre lies behind approximately 27 magnitudes of visual extinction, observations at visible wavelengths are impossible. The recent introduction of charge-coupled devices (CCDs) to astronomy represents the first opportunity to use sensitive area detectors in the near IR. Using a cooled CCD, we have obtained an image of the galactic centre at an effective wavelength of 0.9 µm. Two unresolved sources were found, separated by 3 arc s along the galactic plane. The detection of the two sources was confirmed by a further observation the following night. The possibility that the new sources are foreground objects cannot be completely ruled out; however, their positions are remarkably close to those of the non-thermal radio source and the 2.2 µm source IRS-16. While it is possible that the new sources could be a pair of highly reddened individual stars or compact clusters, it seems more likely that they are two compact H II regions seen in line emission.

Royal Greenwich Observatory (RGO) Charge-Coupled Device (CCD) Camera

A liquid nitrogen cooled CCD camera utilising the RCA 53612 thinned CCD is described. It was constructed primarily for direct imaging at the prime focus of the Anglo Australian Telescope and is now installed as a common user instrument. The camera head, drive electr-onics and microprogrammable controller are briefly described. The camera has been designed to accommodate other CCD chips with minimum modification: many operating modes are available under software control. Operating characteristics and some astronomical results are presented.