| Title: |
ZTF SN Ia DR2: Environmental dependencies of stretch and luminosity for a volume-limited sample of 1000 type Ia supernovae |
| Authors: |
Ginolin, M.; Rigault, M.; Smith, M.; Copin, Y.; Ruppin, F.; Dimitriadis, G.; Goobar, A.; Johansson, J.; Maguire, K.; Nordin, J.; Amenouche, M.; Aubert, M.; Barjou-Delayre, C.; Betoule, M.; Burgaz, U.; Carreres, B.; Deckers, M.; Dhawan, S.; Feinstein, F.; Fouchez, D.; Galbany, L.; Ganot, C.; Harvey, L.; de Jaeger, T.; Kenworthy, W. D.; Kim, Y.-L.; Kowalski, M.; Kuhn, D.; Lacroix, L.; Müller-Bravo, T. E.; Nugent, P.; Popovic, B.; Racine, B.; Rosnet, P.; Rosselli, D.; Sollerman, J.; Terwel, J. H.; Townsend, A.; Brugger, J.; Bellm, E. C.; Kasliwal, M. M.; Kulkarni, S.; Laher, R. R.; Masci, F. J.; Riddle, R. L.; Sharma, Y. |
| Contributors: |
Institut de Physique des 2 Infinis de Lyon (IP2I Lyon); Université Claude Bernard Lyon 1 (UCBL); Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS); Laboratoire de Physique de Clermont (LPC); Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA); Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)); Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS); Centre de Physique des Particules de Marseille (CPPM); Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS) |
| Source: |
ISSN: 0004-6361. |
| Publisher Information: |
CCSD; EDP Sciences |
| Publication Year: |
2025 |
| Collection: |
HAL Lyon 1 (University Claude Bernard Lyon 1) |
| Subject Terms: |
dark energy; supernovae: general; [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] |
| Description: |
International audience ; Context. Type Ia supernova (SN Ia) cosmology studies will soon be dominated by systematic, uncertainties, rather than statistical ones. Thus, it is crucial to understand the unknown phenomena potentially affecting their luminosity that may remain, such as astrophysical biases. For their accurate application in such studies, SN Ia magnitudes need to be standardised; namely, they must be corrected for their correlation with the light-curve width and colour.Aims. Here, we investigate how the standardisation procedure used to reduce the scatter of SN Ia luminosities is affected by their environment. Our aim is to reduce scatter and improve the standardisation process.Methods. We first studied the SN Ia stretch distribution, as well as its dependence on environment, as characterised by local and global (g − z) colour and stellar mass. We then looked at the standardisation parameter, α, which accounts for the correlation between residuals and stretch, along with its environment dependency and linearity. Finally, we computed the magnitude offsets between SNe in different astrophysical environments after the colour and stretch standardisations (i.e. steps). This analysis has been made possible thanks to the unprecedented statistics of the volume-limited Zwicky Transient Facility (ZTF) SN Ia DR2 sample.Results. The stretch distribution exhibits a bimodal behaviour, as previously found in the literature. However, we find the distribution to be dependent on environment. Specifically, the mean stretch modes decrease with host stellar mass, at a 9.2σ significance. We demonstrate, at the 13.4σ level, that the stretch-magnitude relation is non-linear, challenging the usual linear stretch-residuals relation currently used in cosmological analyses. In fitting for a broken-α model, we did indeed find two different slopes between stretch regimes (x1 ≶ x10 with x10 = −0.48 ± 0.08): αlow = 0.271 ± 0.011 and αhigh = 0.083 ± 0.009, comprising a difference of Δα = −0.188 ± 0.014. As the relative proportion of ... |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
info:eu-repo/semantics/altIdentifier/arxiv/2405.20965; ARXIV: 2405.20965; INSPIRE: 2793112 |
| DOI: |
10.1051/0004-6361/202450378 |
| Availability: |
https://hal.science/hal-04992553; https://hal.science/hal-04992553v1/document; https://hal.science/hal-04992553v1/file/aa50378-24.pdf; https://doi.org/10.1051/0004-6361/202450378 |
| Rights: |
https://about.hal.science/hal-authorisation-v1/ ; info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.1441F77B |
| Database: |
BASE |