English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present the analysis underpinning the measurement of cosmologicalparameters from 207 spectroscopically classified type Ia supernovae (SNe Ia)from the first three years of the Dark Energy Survey Supernova Program(DES-SN), spanning a redshift range of 0.017<$z$<0.849. We combine the DES-SNsample with an external sample of 122 low-redshift ($z$<0.1) SNe Ia, resultingin a "DES-SN3YR" sample of 329 SNe Ia. Our cosmological analyses are blinded:after combining our DES-SN3YR distances with constraints from the CosmicMicrowave Background (CMB; Planck Collaboration 2016), our uncertainties in themeasurement of the dark energy equation-of-state parameter, $w$, are .042(stat) and .059 (stat+syst) at 68% confidence. We provide a detailed systematicuncertainty budget, which has nearly equal contributions from photometriccalibration, astrophysical bias corrections, and instrumental bias corrections.We also include several new sources of systematic uncertainty. While our sampleis <1/3 the size of the Pantheon sample, our constraints on $w$ are only largerby 1.4$\times$, showing the impact of the DES SN Ia light curve quality. Wefind that the traditional stretch and color standardization parameters of theDES SNe Ia are in agreement with earlier SN Ia samples such as Pan-STARRS1 andthe Supernova Legacy Survey. However, we find smaller intrinsic scatter aboutthe Hubble diagram (0.077 mag). Interestingly, we find no evidence for a Hubbleresidual step ( 0.007 $\pm$ 0.018 mag) as a function of host galaxy mass forthe DES subset, in 2.4$\sigma$ tension with previous measurements. We alsopresent novel validation methods of our sample using simulated SNe Ia insertedin DECam images and using large catalog-level simulations to test for biases inour analysis pipelines.

First Cosmology Results Using Type Ia Supernovae From the Dark Energy Survey: Analysis, Systematic Uncertainties, and Validation