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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - The Dark Energy Survey Supernova Program
T2 - slow supernovae show cosmological time dilation out to z ~ 1.
AU - Dark Energy Survey Collaboration
AU - White, Ryan M. T.
AU - Davis, Tamara M.
AU - Lewis, Geraint F.
AU - Lidman, Christopher
AU - Shah, Paul
AU - Abbott, T. M. C.
AU - Aguena, M.
AU - Allam, S.
AU - Andrade-Oliveira, F.
AU - Asorey, J.
AU - Bacon, D.
AU - Bocquet, S.
AU - Brooks, D.
AU - Brout, D.
AU - Buckley-Geer, E.
AU - Burke, D. L.
AU - Carnero Rosell, A.
AU - Carollo, D.
AU - Carretero, J.
AU - da Costa, L. N.
AU - Pereira, M. E. S.
AU - De Vicente, J.
AU - Desai, S.
AU - Diehl, H. T.
AU - Everett, S.
AU - Ferrero, I.
AU - Flaugher, B.
AU - Frieman, J.
AU - García-Bellido, J.
AU - Gaztanaga, E.
AU - Giannini, G.
AU - Glazebrook, K.
AU - Gruendl, R. A.
AU - Hinton, S. R.
AU - Hollowood, D. L.
AU - Honscheid, K.
AU - James, D. J.
AU - Kessler, R.
AU - Kuehn, K.
AU - Lahav, O.
AU - Lee, J.
AU - Lee, S.
AU - Lima, M.
AU - Marshall, J. L.
AU - Mena-Fernández, J.
AU - Miquel, R.
AU - Myles, J.
AU - Möller, A.
AU - Nichol, R. C.
AU - Smith, M.
PY - 2024/9/21
Y1 - 2024/9/21
N2 - 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....
AB - 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....
U2 - 10.1093/mnras/stae2008
DO - 10.1093/mnras/stae2008
M3 - Journal article
VL - 533
SP - 3365
EP - 3378
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 3
ER -