The effect of environment on Type Ia supernovae in the Dark Energy Survey three-year cosmological sample. Issue 4 (21st December 2020)

• Record Type: Journal Article
• Authors: Kelsey, L; Sullivan, M; Smith, M; Wiseman, P; Brout, D; Davis, T M; Frohmaier, C; Galbany, L; Grayling, M; Gutiérrez, C P; Hinton, S R; Kessler, R; Lidman, C; Möller, A; Sako, M; Scolnic, D; Uddin, S A; Vincenzi, M; Abbott, T M C; Aguena, M; Allam, S; Annis, J; Avila, S; Bacon, D; Bertin, E; Brooks, D; Burke, D L; Carnero Rosell, A; Carrasco Kind, M; Carretero, J; Castander, F J; Costanzi, M; da Costa, L N; Desai, S; Diehl, H T; Doel, P; Everett, S; Ferrero, I; Ferté, A; Flaugher, B; Fosalba, P; García-Bellido, J; Gerdes, D W; Gruen, D; Gruendl, R A; Gschwend, J; Gutierrez, G; Hollowood, D L; Honscheid, K; James, D J; Kim, A G; Kuehn, K; Kuropatkin, N; Lahav, O; Lima, M; Marshall, J L; Martini, P; Menanteau, F; Miquel, R; Morgan, R; Ogando, R L C; Palmese, A; Paz-Chinchón, F; Plazas, A A; Romer, A K; Sánchez, C; Sanchez, E; Serrano, S; Sevilla-Noarbe, I; Suchyta, E; Tarle, G; Thomas, D; To, C; Varga, T N; Walker, A R; Wilkinson, R D;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 501:Issue 4(2021)
• Page Start: 4861
• Page End: 4876
• Publication Date: 2020-12-21
• Subjects: surveys -- supernovae: general -- distance scale -- cosmology: observations; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa3924
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Analyses of Type Ia supernovae (SNe Ia) have found puzzling correlations between their standardized luminosities and host galaxy properties: SNe Ia in high-mass, passive hosts appear brighter than those in lower mass, star-forming hosts. We examine the host galaxies of SNe Ia in the Dark Energy Survey 3-yr spectroscopically confirmed cosmological sample, obtaining photometry in a series of 'local' apertures centred on the SN, and for the global host galaxy. We study the differences in these host galaxy properties, such as stellar mass and rest-frame U − R colours, and their correlations with SN Ia parameters including Hubble residuals. We find all Hubble residual steps to be >3 σ in significance, both for splitting at the traditional environmental property sample median and for the step of maximum significance. For stellar mass, we find a maximal local step of 0.098 ± 0.018 mag; ∼0.03 mag greater than the largest global stellar mass step in our sample (0.070 ± 0.017 mag). When splitting at the sample median, differences between local and global U − R steps are small, both ∼0.08 mag, but are more significant than the global stellar mass step (0.057 ± 0.017 mag). We split the data into sub-samples based on SN Ia light-curve parameters: stretch ( x 1 ) and colour ( c ), finding that redder objects ( c > 0) have larger Hubble residual steps, for both stellar mass and U − R, for both local and global measurements, of ∼0.14 mag. Additionally, the bluer (star-forming) local environments host a more homogeneous SN Ia sample, with local U − R rms scatter as low as 0.084 ± 0.017 mag for blue ( c < 0) SNe Ia in locally blue U − R environments.