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

The H-magnitude aperture data published by the Aaronson et al. collaboration over a 10 year period is collected into a homogeneous data set of 1731 observations of 665 galaxies. Ninety-six percent of these galaxies have isophotal diameters and axial ratios determined by the Third Reference Cataloque of Bright Galaxies (RC3; de Vaucouleurs et al. 1991), 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 Vaucouleurs, de Vaucouleurs, & 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-magnitudes, prompting the present recalibration of the near-infrared Tully-Fisher relationship. New optically normalized H-magnitude growth curves are defined for galaxies of types SO to Im, from which new values of fiducial H-magnitudes, Hg-0.5, are measured for the 665 galaxies. A series 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 or equal to log (A/Dg) less than or equal to -0.2. Comparisons with the Aaronson et al. values of diameters, axial ratios, and fiducial H-magnitudes show the expected differences, given the different definitions of these parameters. The values of Hg-0.5 are assigned quality indices: 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 indicates 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 defiend by the RC3.