% TEX version of NRAO Radio CD-ROM image submission form % Version 91/3/28 J. J. Condon \nopagenumbers \centerline{\bf NRAO CD-ROM IMAGE SUBMISSION FORM} \bigskip \noindent Image Donor(s): Donald C.~Wells \bigskip \noindent Contact donor: Donald C.~Wells Mailing address: National Radio Astronomy Observatory, Edgemont Road, Charlottesville, Virginia 22903-2475 USA \bigskip \bigskip Telephone: 1-804-296-0277 E-mail address: dwells@nrao.edu \bigskip \noindent Source or Image Name: NGC~6503 \noindent Alternate Names: \noindent Description of Observation: (e.g., date of observation, telescope(s) used, frequencies, polarization type, resolution, deconvolution method) NGC~6503 (17:49:57.7, +70:09:25.7 [1950], L=100, b=30.5) is a normal spiral galaxy, with morphological type SA(s)cd (de~Vaucouleurs). The observation had a total duration of 4~hours, on 12-April-1983, and used 21 antennas in C array, with 32 channels at 48~KHz spacing (10~km/s), and integration time 60~sec. Exposure time on the galaxy was about 2~hours. \vfill \noindent Description of Image: (e.g., type of source, scientific reason for observing, notable source features) This 21~cm cube is a {\it textbook case} of a spiral galaxy rotation curve. The AIPS task {\tt GAL} was developed and debugged using this observation as the test data. The cube has also been used extensively by the AIPS Group for testing ``movie loop'' display code and for various visualization experiments. The 1.1~Jy quasar 1749+70.1 was within the primary beam at L band. The quasar totally dominated the dirty maps, its sidelobes being about 10x brighter than the 21~cm galaxy emission. The 6~MHz continuum map delivered with the cube was subtracted from each of the 31 planes of the cube, and the quasar disappeared completely. \vfill \vfill \noindent Publication Reference(s): van Moorsel, G. A., and Wells, D. C., "Analysis of High Resolution Velocity Fields --- NGC~6503", AJ~{\bf 90}, 1038 (1985). \bigskip \bigskip \noindent Permission is granted to NRAO/AUI to use, distribute, sell, reproduce or authorize others to use, distribute, sell or reproduce the images listed above without reservation or restriction. The donor whose signature appears below agrees to inform all co-authors of this release. \bigskip \noindent Signed: \medskip \noindent Date: 29~August~1991 \eject \end