Steve: A Hierarchical Bayesian Model for Supernova Cosmology Academic Article uri icon

abstract

  • Abstract We present a new Bayesian hierarchical model (BHM) named Steve for performing Type Ia supernova (SN Ia) cosmology fits. This advances previous works by including an improved treatment of Malmquist bias, accounting for additional sources of systematic uncertainty, and increasing numerical efficiency. Given light-curve fit parameters, redshifts, and host-galaxy masses, we fit Steve simultaneously for parameters describing cosmology, SNIa populations, and systematic uncertainties. Selection effects are characterized using Monte Carlo simulations. We demonstrate its implementation by fitting realizations of SNIa data sets where the SNIa model closely follows that used in Steve. Next, we validate on more realistic SNANA simulations of SNIa samples from the Dark Energy Survey and low-redshift surveys (DES Collaboration et al. 2018). These simulated data sets contain more than 60,000 SNeIa, which we use to evaluate biases in the recovery of cosmological parameters, specifically the equation of state of dark energy, w. This is the most rigorous test of a BHM method applied to SNIa cosmology fitting and reveals small w biases that depend on the simulated SNIa properties, in particular the intrinsic SNIa scatter model. This w bias is less than 0.03 on average, less than half the statistical uncertainty on w. These simulation test results are a concern for BHM cosmology fitting applications on large upcoming surveys; therefore, future development will focus on minimizing the sensitivity of Steve to the SNIa intrinsic scatter model.

published proceedings

  • ASTROPHYSICAL JOURNAL

altmetric score

  • 14.862

author list (cited authors)

  • Hinton, S. R., Davis, T. M., Kim, A. G., Brout, D., D'Andrea, C. B., Kessler, R., ... Zhang, Y.

citation count

  • 19

complete list of authors

  • Hinton, SR||Davis, TM||Kim, AG||Brout, D||D'Andrea, CB||Kessler, R||Lasker, J||Lidman, C||Macaulay, E||Moller, A||Sako, M||Scolnic, D||Smith, M||Wolf, RC||Childress, M||Morganson, E||Allam, S||Annis, J||Avila, S||Bertin, E||Brooks, D||Burke, DL||Carnero Rosell, A||Kind, M Carrasco||Carretero, J||Cunha, CE||da Costa, LN||Davis, C||De Vicente, J||DePoy, DL||Doel, P||Eifler, TF||Flaugher, B||Fosalba, P||Frieman, J||Garcia-Bellido, J||Gaztanaga, E||Gerdes, DW||Gruendl, RA||Gschwend, J||Gutierrez, G||Hartley, WG||Hollowood, DL||Honscheid, K||Krause, E||Kuehn, K||Kuropatkin, N||Lahav, O||Lima, M||Maia, MAG||March, M||Marshall, JL||Menanteau, F||Miquel, R||Ogando, RLC||Plazas, AA||Sanchez, E||Scarpine, V||Schindler, R||Schubnell, M||Serrano, S||Sevilla-Noarbe, I||Soares-Santos, M||Sobreira, F||Suchyta, E||Tarle, G||Thomas, D||Vikram, V||Zhang, Y

publication date

  • May 2019