Hubble Diagrams of Type Ia Supernovae in the Near-Infrared

From observations of 7 Type Ia supernovae obtained during the last four yearsat the Las Campanas and Cerro Tololo Inter-American Observatories, along withprevious published data for 9 supernovae, we present JHK Hubble diagrams andderive absolute magnitudes at maximum light of 16 objects out to a redshift of0.038. On the scale of H_0 = 72 km/s/Mpc we find mean absolute magnitudes atmaximum of -18.57, -18.24, and -18.42 for J, H, and K, respectively, with1-sigma uncertainties of the distributions of values of +/- 0.14, 0.18, and0.12 mag. The data indicate no significant decline rate relations for theinfrared. Thus, Type Ia SNe at maximum brightness appear to be standard candlesin the infrared at the +/- 0.20 mag level or better. The minimum requirementsfor obtaining the distance to a Type Ia SN are: reasonably accurate values ofDelta m_15(B) and T(B_max), and one night of infrared data in the -12 to +10 dwindow with respect to T(B_max).Comment: 15 pages, 3 figures, published in the Astrophysical Journal, vol. 602, pp. L81-L84 (20 February 2004). This version gives more credit where credit is du