Working Group on Galaxy Photometry

Extract

• 1. A tabular presentation has been adopted and the report does not cover work in the U.S.S.R. During the report period Circular No. 6 (Report on Prague Meeting) and a Technical Supplement, No. 6a, were distributed. Work on standard luminosity profiles for a few well-observed galaxies (NGC3115, 3379, 4486) progressed more slowly than expected, but provisional results will be available for presentation at the 1970 meeting.

• 2. On the observational side the major event to report is the publication of an Atlas de Galaxias Australes by J. L. Sěrsic; it gives photographs, descriptions and detailed surface photometry of 50 southern galaxies observed with the 150-cm reflector of Cordoba Observatory. Another important contribution is the dissertation of H. D. Abies on “Optical Study of Nearby Galaxies” of interest to radio astronomy. The isophotometric atlas of 70-80 galaxies and UBV catalogue of 500 galaxies observed by G. and A. de Vaucouleurs at Mt. Stromlo and McDonald Observatories and by H. D. Abies at Flagstaff, F. Bertola at Asiago and other collaborators is being prepared for publication in 1970-71.

On the technical side the rapid development of automatic digital methods for data recording and processing should lead to a great acceleration in the production of precise isophote maps, but most commercial instruments are still deficient with respect to mechanical precision, optical design (stray light, beam definition) and electrical stability.