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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present improved photometric measurements for the host galaxies of 206spectroscopically confirmed type Ia supernovae discovered by the Dark EnergySurvey Supernova Program (DES-SN) and used in the first DES-SN cosmologicalanalysis. Fitting spectral energy distributions to the $griz$ photometricmeasurements of the DES-SN host galaxies, we derive stellar masses andstar-formation rates. For the DES-SN sample, when considering a 5D ($z$, $x_1$,$c$, $\alpha$, $\beta$) bias correction, we find evidence of a Hubble residual`mass step', where SNe Ia in high mass galaxies ($>10^{10} \textrm{M}_{\odot}$)are intrinsically more luminous (after correction) than their low masscounterparts by $\gamma=0.040\pm0.019$mag. This value is larger by $0.031$magthan the value found in the first DES-SN cosmological analysis. This differenceis due to a combination of updated photometric measurements and improved starformation histories and is not from host-galaxy misidentification. When using a1D (redshift-only) bias correction the inferred mass step is larger, with$\gamma=0.066\pm0.020$mag. The 1D-5D $\gamma$ difference for DES-SN is$0.026\pm0.009$mag. We show that this difference is due to a strong correlationbetween host galaxy stellar mass and the $x_1$ component of the 5Ddistance-bias correction. To better understand this effect, we include anintrinsic correlation between light-curve width and stellar mass in simulatedSN Ia samples. We show that a 5D fit recovers $\gamma$ with $-9$mmag biascompared to a $+2$mmag bias for a 1D fit. This difference can explain part ofthe discrepancy seen in the data. Improvements in modeling correlations betweengalaxy properties and SN is necessary to determine the implications for$\gamma$ and ensure unbiased precision estimates of the dark energyequation-of-state as we enter the era of LSST.

First Cosmology Results using Type Ia Supernovae from the Dark Energy Survey: The Effect of Host Galaxy Properties on Supernova Luminosity