ZTF SN Ia DR2: Exploring SN Ia properties in the vicinity of under-dense environments
/ Authors
M. Aubert, P. Rosnet, B. Popovic, F. Ruppin, M. Smith, M. Rigault, G. Dimitriadis, A. Goobar, J. Johansson, C. Barjou-Delayre
and 22 more authors
U. Burgaz, B. Carreres, F. Feinstein, D. Fouchez, L. Galbany, M. Ginolin, T. de Jaeger, M. Kasliwal, Y.-L. Kim, L. Lacroix, F. Masci, T. Müller-Bravo, B. Racine, C. Ravoux, N. Regnault, R. Riddle, D. Rosselli, B. Rusholme, R. Smith, J. Sollerman, J. Terwel, A. Townsend
/ Abstract
Context. The unprecedented statistics of detected Type Ia supernovae (SNe Ia) brought by the Zwicky Transient Facility (ZTF) enable us to probe the impact of the large-scale structure (LSS) on the properties of these objects. Aims. The goal of this paper is to explore the possible impact of the under-dense part of the LSS on the intrinsic SALT2 light-curve properties of SNe Ia and uncover possible biases in SN Ia analyses. Methods. With a volume-limited selection of ZTF-Cosmo-DR2 SNe Ia overlapping with the SDSS-DR7 survey footprint, we investigated the distribution of their properties with regard to voids detected in the SDSS-DR7 galaxy sample. We further used Voronoi volumes as a proxy for local density environments within the LSS. Results. We find a moderate dependency of the stretch on the localisation around the void centre and none when considering colour. The local Voronoi volumes mostly affect the fraction of low- and high-stretch supernovae. Conclusions. With the presently available statistics, we consider that the impact of high- or low-local-density environment can be considered as a proxy for the colour of the host galaxy. Under-dense environments should not cause any biases in analyses of supernova.
Journal: Astronomy & Astrophysics