1205.3494 (D. Rubin et al.)

Precision Measurement of The Most Distant Spectroscopically-Confirmed Supernova Ia with the Hubble Space Telescope    [PDF]

D. Rubin, R. A. Knop, E. Rykoff, G. Aldering, R. Amanullah, K. Barbary, M. S. Burns, A. Conley, N. Connolly, S. Deustua, V. Fadeyev, H. K. Fakhouri, A. S. Fruchter, R. A. Gibbons, G. Goldhaber, A. Goobar, E. Y. Hsiao, X. Huang, M. Kowalski, C. Lidman, J. Meyers, J. Nordin, S. Perlmutter, C. Saunders, A. L. Spadafora, V. Stanishev, N. Suzuki, L. Wang

We report the discovery of a redshift 1.71 supernova in the GOODS North field. The Hubble Space Telescope (HST) ACS spectrum has almost negligible contamination from the host or neighboring galaxies, allowing us to confirm it as a Type Ia. A serendipitous HST WFC3 IR spectrum, taken after the supernova had faded, gives a host-galaxy redshift of 1.713 +/- 0.007 which matches the SN redshift. In addition to being the most distant SN Ia with spectroscopic confirmation, this is the most distant Ia with a precision color measurement. We present the ACS WFC and NICMOS 2 photometry and ACS and WFC3 spectroscopy. Our derived supernova distance is in agreement with the prediction of LambdaCDM.

View original: http://arxiv.org/abs/1205.3494