The Pantheon+ Analysis: SuperCal-Fragilistic Cross Calibration, Retrained SALT2 Light Curve Model, and Calibration Systematic Uncertainty

• DOI: 10.48550/arxiv.2112.03864
• Publication Date: 2021-01-01
• Authors: Dillon Brout; G. Taylor; D. Scolnic; Charlotte M. Wood; Benjamin Rose; M. Vincenzi; Arianna Dwomoh; C. Lidman; Adam G. Riess; Noor Ali; Helen Qu; Mi Dai; C. W. Stubbs
• Keywords: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astronomi, astrofysik och kosmologi; 0103 physical sciences; Astronomy, Astrophysics and Cosmology; FOS: Physical sciences; Astrophysics - Instrumentation and Methods for Astrophysics; Instrumentation and Methods for Astrophysics (astro-ph.IM); 01 natural sciences; Astrophysics - Cosmology and Nongalactic Astrophysics

We present here a re-calibration of the photometric systems used in Pantheon+ sample Type Ia supernovae (SNe Ia) including those for SH0ES distance-ladder measurement H$_0$. utilize large and uniform sky coverage public Pan-STARRS stellar photometry catalog to cross-calibrate against tertiary standards released by individual SN surveys. The most significant updates over `SuperCal' cross-calibration previous Pantheon analyses are: 1) expansion number (now 25) filters 105), 2) solving all filter offsets simultaneously order produce calibration uncertainty covariance matrix that can be cosmological-model constraints, 3) accounting change fundamental flux HST CALSPEC from versions on $1.5\%$ $Δλ$ 4000~Å. samples light-curve fitting has historically been decoupled retraining model. Here, we are able retrain SALT2 model using this new find coupled with light-curves themselves causes net distance modulus ($dμ/dz$) 0.04 mag redshift range $0