Browsing by Author "Rubin, D"

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    A Reference Survey for Supernova Cosmology with the Nancy Grace Roman Space Telescope
    Rose, BM; Baltay, C; Hounsell, R; Macias, P; Rubin, D; Scolnic, D; Aldering, G; Bohlin, R; Dai, M; Deustua, SE; Foley, RJ; Fruchter, A; Galbany, L; Jha, SW; Jones, DO; Joshi, BA; Kelly, PL; Kessler, R; Kirshner, RP; Mandel, KS; Perlmutter, S; Pierel, J; Qu, H; Rabinowitz, D; Rest, A; Riess, AG; Rodney, S; Sako, M; Siebert, MR; Strolger, L; Suzuki, N; Thorp, S; Dyk, SD Van; Wang, K; Ward, SM; Wood-Vasey, WM
    This note presents an initial survey design for the Nancy Grace Roman High-latitude Time Domain Survey. This is not meant to be a final or exhaustive list of all the survey strategy choices, but instead presents a viable path towards achieving the desired precision and accuracy of dark energy measurements using Type Ia supernovae (SNe Ia). We describe a survey strategy that use six filters (RZYJH and F) and the prism on the Roman Wide Field Instrument. This survey has two tiers, one "wide" which targets SNe Ia at redshifts up to 1 and one "deep" targeting redshifts up to 1.7; for each, four filters are used (with Y and J used in both tiers). We propose one field each in the north and south continuous viewing zones, and expect to obtain high-quality distances of $\sim$12,000 SNe Ia with $\sim$5,000 at z > 1. We propose a wide-tier area of $\sim$19 deg$^2$ and a deep tier of $\sim$5 deg$^2$. Exposure times range from 100 s to 900 s for imaging and 900 s to 3600 s for the prism. These exposure times would reach $\sim$25.5 mag and $\sim$26.5 mag for the wide and deep tiers respectively, with deep co-add stacks reaching $\sim$28 mag and $\sim$29 mag. The total survey spans two years, with a total allocation time of six months, and a cadence of $\sim$5 days.
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    No Evidence for Type Ia Supernova Luminosity Evolution: Evidence for Dark Energy is Robust
    Rose, BM; Rubin, D; Cikota, A; Deustua, SE; Dixon, S; Fruchter, A; Jones, DO; Riess, AG; Scolnic, DM
    Type Ia Supernovae (SNe Ia) are powerful standardized candles for constraining the cosmological model and provided the first evidence of accelerated expansion. Their precision derives from empirical correlations now measured from $>1000$ SNe Ia between their luminosities, light curve shapes, colors and most recently a modest relationship with the mass of their host galaxy. As mass correlates with other host properties, these have been investigated to improve SN Ia standardization though none have been shown to significantly alter the determination of cosmological parameters. We re-examine a recent claim, based on 34 SN Ia in nearby passive host galaxies, of a 0.05 mag/Gyr dependence of standardized SN Ia luminosity on host age which if extrapolate to higher redshifts, might accrue to 0.25 mag challenging the inference of dark energy. We reanalyze this sample of hosts using both the original method and a Bayesian Hierarchical Model and find after a fuller accounting of the errors the significance for a dependence on age to be $\leq2\sigma$ and $\sim1\sigma$ after removal of a single poorly-measured SN. To test the claim that a trend seen in old stellar populations can be applied to younger ages, we extend our analysis to a larger sample which includes young hosts. We find the residual dependence of host age (after all standardization typically employed for cosmological measurements) to be $0.0011\pm0.0018$ mag/Gyr ($0.6\sigma$) for 254 SNe Ia from the Pantheon sample, consistent with no trend and strongly ruling out the large but low significance trend claimed from the passive hosts.
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    Synergies between Vera C. Rubin Observatory, Nancy Grace Roman Space Telescope, and Euclid Mission: Constraining Dark Energy with Type Ia Supernovae
    Rose, BM; Aldering, G; Dai, M; Deustua, S; Foley, RJ; Gangler, E; Gris, Ph; Hook, IM; Kessler, R; Narayan, G; Nugent, P; Ponder, S Perlmutte KA; Racine, B; Rubin, D; Sánchez, BO; Scolnic, DM; Wood-Vasey, WM; Brout, D; Cikota, A; Fouchez, D; Garnavich, PM; Hounsell, R; Sako, M; Tao, C; Jha, SW; Jones, DO; Strolger, L; Qu, H
    We review the needs of the supernova community for improvements in survey coordination and data sharing that would significantly boost the constraints on dark energy using samples of Type Ia supernovae from the Vera C. Rubin Observatories, the \textit{Nancy Grace Roman Space Telescope}, and the \textit{Euclid} Mission. We discuss improvements to both statistical and systematic precision that the combination of observations from these experiments will enable. For example, coordination will result in improved photometric calibration, redshift measurements, as well as supernova distances. We also discuss what teams and plans should be put in place now to start preparing for these combined data sets. Specifically, we request coordinated efforts in field selection and survey operations, photometric calibration, spectroscopic follow-up, pixel-level processing, and computing. These efforts will benefit not only experiments with Type Ia supernovae, but all time-domain studies, and cosmology with multi-messenger astrophysics.