The Dark Energy Survey Supernova Program: Slow supernovae show cosmological time dilation out to $z \sim 1$

Autor: White, R. M. T., Davis, T. M., Lewis, G. F., Brout, D., Galbany, L., Glazebrook, K., Hinton, S. R., Lee, J., Lidman, C., Möller, A., Sako, M., Scolnic, D., Smith, M., Sullivan, M., Sánchez, B. O., Shah, P., Vincenzi, M., Wiseman, P., Abbott, T. M. C., Aguena, M., Allam, S., Andrade-Oliveira, F., Asorey, J., Bacon, D., Bocquet, S., Brooks, D., Buckley-Geer, E., Burke, D. L., Rosell, A. Carnero, Carollo, D., Carretero, J., da Costa, L. N., Pereira, M. E. S., De Vicente, J., Desai, S., Diehl, H. T., Everett, S., Ferrero, I., Flaugher, B., Frieman, J., García-Bellido, J., Gaztanaga, E., Giannini, G., Gruendl, R. A., Hollowood, D. L., Honscheid, K., James, D. J., Kessler, R., Kuehn, K., Lahav, O., Lee, S., Lima, M., Marshall, J. L., Mena-Fernández, J., Miquel, R., Myles, J., Nichol, R. C., Ogando, R. L. C., Palmese, A., Pieres, A., Malagón, A. A. Plazas, Romer, A. K., Sanchez, E., Cid, D. Sanchez, Schubnell, M., Suchyta, E., Tarle, G., Tucker, B. E., Walker, A. R., Weaverdyck, N.
Rok vydání: 2024
Předmět:
Druh dokumentu: Working Paper
Popis: We present a precise measurement of cosmological time dilation using the light curves of 1504 type Ia supernovae from the Dark Energy Survey spanning a redshift range $0.1\lesssim z\lesssim 1.2$. We find that the width of supernova light curves is proportional to $(1+z)$, as expected for time dilation due to the expansion of the Universe. Assuming type Ia supernovae light curves are emitted with a consistent duration $\Delta t_{\rm em}$, and parameterising the observed duration as $\Delta t_{\rm obs}=\Delta t_{\rm em}(1+z)^b$, we fit for the form of time dilation using two methods. Firstly, we find that a power of $b \approx 1$ minimises the flux scatter in stacked subsamples of light curves across different redshifts. Secondly, we fit each target supernova to a stacked light curve (stacking all supernovae with observed bandpasses matching that of the target light curve) and find $b=1.003\pm0.005$ (stat) $\pm\,0.010$ (sys). Thanks to the large number of supernovae and large redshift-range of the sample, this analysis gives the most precise measurement of cosmological time dilation to date, ruling out any non-time-dilating cosmological models at very high significance.
Comment: 14 pages, 13 figures. Updated in response to reviewer feedback. Accepted for publication in the Monthly Notices of the Royal Astronomical Society (MNRAS)
Databáze: arXiv