The Dark Energy Survey Supernova Program results: type Ia supernova brightness correlates with host galaxy dust. Issue 2 (26th October 2022)

• Record Type: Journal Article
• Authors: Meldorf, C; Palmese, A; Brout, D; Chen, R; Scolnic, D; Kelsey, L; Galbany, L; Hartley, W G; Davis, T M; Drlica-Wagner, A; Vincenzi, M; Annis, J; Dixon, M; Graur, O; Lidman, C; Möller, A; Nugent, P; Rose, B; Smith, M; Allam, S; Tucker, D L; Asorey, J; Calcino, J; Carollo, D; Glazebrook, K; Lewis, G F; Taylor, G; Tucker, B E; Kim, A G; Diehl, H T; Aguena, M; Andrade-Oliveira, F; Bacon, D; Bertin, E; Bocquet, S; Brooks, D; Burke, D L; Carretero, J; Carrasco Kind, M; Castander, F J; Costanzi, M; da Costa, L N; Desai, S; Doel, P; Everett, S; Ferrero, I; Friedel, D; Frieman, J; García-Bellido, J; Gatti, M; Gruen, D; Gschwend, J; Gutierrez, G; Hinton, S R; Hollowood, D L; Honscheid, K; James, D J; Kuehn, K; March, M; Marshall, J L; Menanteau, F; Miquel, R; Morgan, R; Paz-Chinchón, F; Pereira, M E S; Plazas Malagón, A A; Sanchez, E; Scarpine, V; Sevilla-Noarbe, I; Suchyta, E; Tarle, G; Varga, T N;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 518:Issue 2(2023)
• Page Start: 1985
• Page End: 2004
• Publication Date: 2022-10-26
• Subjects: surveys -- supernovae: general -- galaxies: general -- cosmology: observations; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac3056
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Cosmological analyses with type Ia supernovae (SNe Ia) often assume a single empirical relation between colour and luminosity (β) and do not account for varying host-galaxy dust properties. However, from studies of dust in large samples of galaxies, it is known that dust attenuation can vary significantly. Here, we take advantage of state-of-the-art modelling of galaxy properties to characterize dust parameters (dust attenuation AV, and a parameter describing the dust law slope RV ) for 1100 Dark Energy Survey (DES) SN host galaxies. Utilizing optical and infrared data of the hosts alone, we find three key aspects of host dust that impact SN cosmology: (1) there exists a large range (∼1–6) of host RV ; (2) high-stellar mass hosts have RV on average ∼0.7 lower than that of low-mass hosts; (3) for a subsample of 81 spectroscopically classified SNe there is a significant (>3σ) correlation between the Hubble diagram residuals of red SNe Ia and the host RV that when corrected for reduces scatter by $\sim 13{{\ \rm per\ cent}}$ and the significance of the 'mass step' to ∼1σ. These represent independent confirmations of recent predictions based on dust that attempted to explain the puzzling 'mass step' and intrinsic scatter (σint ) in SN Ia analyses.