Steven A. Rodney, Adam G. Riess, Tomas Dahlen, Louis-Gregory Strolger, Henry C. Ferguson, Jens Hjorth, Teddy F. Frederiksen, Benjamin J. Weiner, Bahram Mobasher, Stefano Casertano, David O. Jones, Peter Challis, S. M. Faber, Alexei V. Filippenko, Peter Garnavich, Or Graur, Norman A. Grogin, Brian Hayden, Saurabh W. Jha, Robert P. Kirshner, Dale Kocevski, Anton Koekemoer, Curtis McCully, Brandon Patel, Abhijith Rajan, Claudia Scarlata
We report the discovery of a Type Ia supernova (SNIa) at redshift z=1.55 with
the infrared detector of the Wide Field Camera 3 (WFC3-IR) on the Hubble Space
Telescope (HST). This object was discovered in CANDELS imaging data of the
Hubble Ultra Deep Field, and followed as part of the CANDELS+CLASH Supernova
project, comprising the SN search components from those two HST multi-cycle
treasury programs. This is the highest redshift SNIa with direct spectroscopic
evidence for classification. It is also the first SN Ia at z>1 found and
followed in the infrared, providing a full light curve in rest-frame optical
bands. The classification and redshift are securely defined from a combination
of multi-band and multi-epoch photometry of the SN, ground-based spectroscopy
of the host galaxy, and WFC3-IR grism spectroscopy of both the SN and host.
This object is the first of a projected sample at z>1.5 that will be discovered
by the CANDELS and CLASH programs. The full CANDELS+CLASH SN Ia sample will
enable unique tests for evolutionary effects that could arise due to
differences in SN Ia progenitor systems as a function of redshift. This high-z
sample will also allow measurement of the SN Ia rate out to z~2, providing a
complementary constraint on SN Ia progenitor models.
View original:
http://arxiv.org/abs/1201.2470
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