Mass-to-Light Ratios of Spiral Galaxies

J. Patricia Vader
1987 Symposium - International astronomical union  
Mass-to-light ratios M/LH−0.5 and M/LB are plotted against color B-H−0.5 in Fig. 1 for 82 nearby spirals from the catalog of Aaronson et al. (1982, Ap. J. Suppl. 50, 241), with BT magnitudes from the RC2, |b| > 20°, 45° ≤ i ≤ 80°, and HI mass estimates. Total masses and infrared H−0.5 magnitudes are measured within the blue isophotal radii R25 and R25/3 respectively, which depend on galaxy color. This color bias is corrected for by replacing R25 by R'25, the radius a galaxy would have at a
more » ... ard color B-H−0.5 = 2.17. Stellar masses M* and LHC luminosities within R'25 are obtained by substracting twice the HI mass and by extrapolation, respectively. Corrected ratios M*/LHC and M*/LB versus corrected color B-HC are shown in Fig. 1 together with theoretical model predictions. The corrected observed ratios are systematically larger for bluer galaxies than predicted so that bluer spirals seem to have relatively more massive halos, in agreement with earlier results (Tinsley, B.M. 1981 M.N.R.A.S. 194, 63; Vader, J. P. 1984, in Formation and Evolution of Galaxies and Large Structures in the Universe, eds. J. Audouze and J. T. Thanh Van, p. 227).
doi:10.1017/s0074180900150107 fatcat:dfkahnctfvchzlhsllv6xhreie