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arXiv · 1211.4480

Cosmology with Photometrically-Classified Type Ia Supernovae from the SDSS-II Supernova Survey

Abstract

We present the cosmological analysis of 752 photometrically-classified Type Ia Supernovae (SNe Ia) obtained from the full Sloan Digital Sky Survey II (SDSS-II) Supernova (SN) Survey, supplemented with host-galaxy spectroscopy from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). Our photometric-classification method is based on the SN typing technique of Sako et al. (2011), aided by host galaxy redshifts (0.05<z<0.55). SNANA simulations of our methodology estimate that we have a SN Ia typing efficiency of 70.8%, with only 3.9% contamination from core-collapse (non-Ia) SNe. We demonstrate that this level of contamination has no effect on our cosmological constraints. We quantify and correct for our selection effects (e.g., Malmquist bias) using simulations. When fitting to a flat LambdaCDM cosmological model, we find that our photometric sample alone gives omega_m=0.24+0.07-0.05 (statistical errors only). If we relax the constraint on flatness, then our sample provides competitive joint statistical constraints on omega_m and omega_lambda, comparable to those derived from the spectroscopically-confirmed three-year Supernova Legacy Survey (SNLS3). Using only our data, the statistics-only result favors an accelerating universe at 99.96% confidence. Assuming a constant wCDM cosmological model, and combining with H0, CMB and LRG data, we obtain w=-0.96+0.10-0.10, omega_m=0.29+0.02-0.02 and omega_k=0.00+0.03-0.02 (statistical errors only), which is competitive with similar spectroscopically confirmed SNe Ia analyses. Overall this comparison is re-assuring, considering the lower redshift leverage of the SDSS-II SN sample (z<0.55) and the lack of spectroscopic confirmation used herein. These results demonstrate the potential of photometrically-classified SNe Ia samples in improving cosmological constraints.

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BibTeXRIS

Heather Campbell, Chris B. D'Andrea, Robert C. Nichol, Masao Sako, Mathew Smith, Hubert Lampeitl, Matthew D. Olmstead, Bruce Bassett, Rahul Biswas, Peter Brown, David Cinabro, Kyle S. Dawson, Ben Dilday, Ryan J. Foley, Joshua A. Frieman, Peter Garnavich, Renee Hlozek, Saurabh W. Jha, Steve Kuhlmann, Martin Kunz, John Marriner, Ramon Miquel, Michael Richmond, Adam Riess, Donald P. Schneider, Jesper Sollerman, Matt Taylor, Gong-Bo Zhao. 2013-08-02. Cosmology with Photometrically-Classified Type Ia Supernovae from the SDSS-II Supernova Survey. https://doi.org/10.1088/0004-637x%2F763%2F2%2F88

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