RECALIBRATION OF THE H(-0.5)-MAGNITUDES OF SPIRAL GALAXIES

The H-magnitude aperture data published by the Aaronson et al. collabo ration over a 10 year period is collected into a homogeneous data set of 1731 observations of 665 galaxies. Ninety-six percent of these gala xies have isophotal diameters and axial ratios determined by the Third Reference Catalogue of Bright Galaxies (RC3; de Vaucouleurs et al. 19 91), the most self-consistent set of optical data currently available. The precepts governing the optical data in the RC3 are systematically different from those of the Second Reference Catalogue (de Vaucouleur s, de Vaucouleurs, and Corwin 1976), which were used by Aaronson et al . for their original analyses of galaxy peculiar motions. This in turn leads to systematic differences in growth curves and fiducial H-magni tudes, prompting the present recalibration of the near-infrared Tully- Fisher relationship. New optically normalized H-magnitude growth curve s are defined for galaxies of types S0 to Im, from which new values of fiducial H-magnitudes, H--0.5(g), measured for the 665 galaxies. A se ries of internal tests show that these four standard growth curves are defined to an accuracy of 0.05 mag over the interval -1.5 less than o r equal to log (A/D-g) less than or equal to -0.2. Comparisons with th e Aaronson et al. values of diameters, axial ratios, and fiducial H-ma gnitudes show the expected differences, given the different definition s of these parameters. The values of H--0.5(g) are assigned quality in dices: a quality value of 1 indicates an accuracy of less than 0.2 mag , quality 2 indicates an accuracy of 0.2-0.35 mag, and quality 3 indic ates an accuracy of more than 0.35 mag. Revised values of corrected H I velocity widths are also given, based on the new set of axial ratios defined by the RC3.