R. L. Barone-Nugent, C. Lidman, J. S. B. Wyithe, J. Mould, D. A. Howell, I. M. Hook, M. Sullivan, P. E. Nugent, I. Arcavi, S. B. Cenko, J. Cooke, A. Gal-Yam, E. Y. Hsiao, M. M. Kasliwal, K. Maguire, E. Ofek, D. Poznanski, D. Xu
We present an analysis of the Hubble diagram for 12 Type Ia supernovae (SNe Ia) observed in the near-infrared J- and H-bands. We select SNe exclusively from the redshift range 0.03 < z < 0.09 to reduce uncertainties coming from peculiar velocities while remaining in a cosmologically well-understood region. Our results suggest that SNe Ia observed in the near-infrared (NIR) are the best known standard candles. We fit previously determined NIR light-curve templates to new high-precision data to derive peak magnitudes and to determine the scatter about the Hubble line. Using a standard cosmology of (H_0, Omega_m, Lambda) = (70,0.27,0.73) we find a median J-band absolute magnitude of M_J = -18.39 with a scatter of 0.116 and a median H- band absolute magnitude of M_H = -18.36 with a scatter of 0.085. The scatter in the H-band is the smallest yet measured. We search for correlations between residuals in the J- and H-band Hubble diagrams and SN properties, such as SN colour, B- band stretch and the projected distance from host-galaxy centre. The only significant correlation is between the J-band Hubble residual and the J-H pseudo-colour. We also examine how the scatter changes when fewer points in the near-infrared are used to constrain the light curve. With a single point in the H-band taken anywhere from 10 days before to 15 days after B-band maximum light and a prior on the date of H- band maximum set from the date of B-band maximum, we find that we can measure distances to an accuracy of 6%. The precision of SNe Ia in the NIR provides new opportunities for precision measurements of both the expansion history of the universe and peculiar velocities of nearby galaxies.
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http://arxiv.org/abs/1204.2308
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