A Sample of Dust Attenuation Laws for DES Supernova Host Galaxies
Creators: name: Duarte, J.
name: González-Gaitán, S.
name: Mourao, A.
name: Paulino-Afonso, A.
name: Guilherme-Garcia, P.
name: Aguas, J.
name: Galbany, L.
name: Kelsey, L.
name: Scolnic, D.
name: Sullivan, M.
name: Brout, D.
name: Palmese, A.
name: Wiseman, P.
name: Pieres, A.
name: Malagón, A. A. Plazas
name: Rosell, A. Carnero
name: To, C.
name: Gruen, D.
name: Bacon, D.
name: Brooks, D.
name: Burke, D. L.
name: Gerdes, D. W.
name: James, D. J.
name: Hollowood, D. L.
name: Friedel, D.
name: Bertin, E.
name: Suchyta, E.
name: Sanchez, E.
name: Paz-Chinchón, F.
name: Gutierrez, G.
name: Tarle, G.
name: Diehl, H. T.
name: Sevilla-Noarbe, I.
name: Ferrero, I.
name: Carretero, J.
name: Frieman, J.
name: De Vicente, J.
name: García-Bellido, J.
name: Honscheid, K.
name: Kuehn, K.
name: Gatti, M.
name: Raveri, M.
name: Pereira, M. E. S.
name: Rodriguez-Monroy, M.
name: Smith, M.
name: Kind, M. Carrasco
name: Costanzi, M.
name: Aguena, M.
name: Kuropatkin, N.
name: Weaverdyck, N.
name: Alves, O.
name: Doel, P.
name: Melchior, P.
name: Miquel, R.
name: Gruendl, R. A.
name: Hinton, S. R.
name: Bocquet, S.
name: Desai, S.
name: Everett, S.
name: Davis, T. M.
name: Scarpine, V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Type Ia supernovae (SNe Ia) are useful distance indicators in cosmology, provided their luminosity is standardized by applying empirical corrections based on light-curve properties. One factor behind these corrections is dust extinction, accounted for in the color-luminosity relation of the standardization. This relation is usually assumed to be universal, which could potentially introduce systematics into the standardization. The ``mass-step'' observed for SNe Ia Hubble residuals has been suggested as one such systematic. We seek to obtain a completer view of dust attenuation properties for a sample of 162 SN Ia host galaxies and to probe their link to the ``mass-step''. We infer attenuation laws towards hosts from both global and local (4 kpc) Dark Energy Survey photometry and Composite Stellar Population model fits. We recover a optical depth/attenuation slope relation, best explained by differing star/dust geometry for different galaxy orientations, which is significantly different from the optical depth/extinction slope relation observed directly for SNe. We obtain a large variation of attenuation slopes and confirm these change with host properties, like stellar mass and age, meaning a universal SN Ia correction should ideally not be assumed. Analyzing the cosmological standardization, we find evidence for a ``mass-step'' and a two dimensional ``dust-step'', both more pronounced for red SNe. Although comparable, the two steps are found no to be completely analogous. We conclude that host galaxy dust data cannot fully account for the ``mass-step'', using either an alternative SN standardization with extinction proxied by host attenuation or a ``dust-step'' approach.
description: 20 pages, 10 figues, 9 tables. Supplementary material included (10 pages). Accepted for publication on A&amp;A