Hubble diagrams of Type Ia supernovae in the near-infrared

From observations of seven Type Ia supernovae obtained during the last 4 years at the Las Campanas and Cerro Tololo Inter- American Observatories, along with previous published data for nine supernovae, we present JHK Hubble diagrams and derive absolute magnitudes at maximum light of 16 objects out to a redshift of 0.038. On the scale of H(0) = 72 km s(-1) Mpc(-1) we find mean absolute magnitudes of - 18.57, - 18.24, and - 18.42 for J, H, and K, respectively, with 1 sigma uncertainties of the distributions of values of +/- 0.14, 0.18, and 0.12 mag. The data indicate no significant decline rate relations for the infrared. Thus, Type Ia supernovae at maximum brightness appear to be standard candles in the infrared at the +/- 0.20 mag level or better. The minimum requirements for obtaining the distance to a Type Ia supernova are reasonably accurate values of and Deltam(15) ( B) and T(B(max)), and one night of infrared data in the - 12 to + 10 day window with respect to T( B(max)).