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Dependence of Type Ia supernova luminosities on their local environment

Dependence of Type Ia supernova luminosities on their local environment
Dependence of Type Ia supernova luminosities on their local environment

We present a fully consistent catalog of local and global properties of host galaxies of 882 Type Ia supernovæ (SNIa) that were selected based on their light-curve properties, spanning the redshift range 0.01 < z < 1. This catalog corresponds to a preliminary version of the compilation sample and includes Supernova Legacy Survey (SNLS) 5-year data, Sloan Digital Sky Survey (SDSS), and low-redshift surveys. We measured low- and moderate-redshift host galaxy photometry in SDSS stacked and single-epoch images and used spectral energy distribution fitting techniques to derive host properties such as stellar mass and U - V rest-frame colors; the latter are an indicator of the luminosity-weighted age of the stellar population in a galaxy. We combined these results with high-redshift host photometry from the SNLS survey and thus obtained a consistent catalog of host stellar masses and colors across a wide redshift range. We also estimated the local observed fluxes at the supernova location within a proper distance radius of 3 kpc, corresponding to the SNLS imaging resolution, and transposed them into local U - V rest-frame colors. This is the first time that local environments surrounding SNIa have been measured at redshifts spanning the entire Hubble diagram. Selecting SNIa based on host photometry quality, we then performed cosmological fits using local color as a third standardization variable, for which we split the sample at the median value. We find a local color step significance of - 0.091 ± 0.013 mag (7σ), which effect is as significant as the maximum mass step effect. This indicates that the remaining luminosity variations in SNIa samples can be reduced with a third standardization variable that takes the environment into account. Correcting for the maximum mass step correction of - 0.094 ± 0.013 mag, we find a local color effect of - 0.057 ± 0.012 mag (5σ), which shows that additional information is provided by the close environment of SNIa. Departures from the initial choices were investigated and showed that the local color effect is still present, although less pronounced. We discuss the possible implications for cosmology and find that using the local color in place of the stellar mass results in a change in the measured value of the dark energy equation-of-state parameter of 0.6%. Standardization using local U - V color in addition to stretch and color reduces the total dispersion in the Hubble diagram from 0.15 to 0.14 mag. This will be of tremendous importance for the forthcoming SNIa surveys, and in particular for the Large Synoptic Survey Telescope (LSST), for which uncertainties on the dark energy equation of state will be comparable to the effects reported here.

Dark energy, Galaxies: photometry, Methods: data analysis, Supernovae: general, Techniques: image processing, Techniques: photometric
0004-6361
Roman, M.
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Hardin, D.
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Betoule, M.
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Astier, P.
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Balland, C.
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Ellis, R. S.
666774eb-188f-4ec2-970f-0889a0cae5f9
Fabbro, S.
fac46460-400b-4fc6-bd93-646112d62ec7
Guy, J.
988d8cfb-8a2c-4c9c-b316-6cfa562e00a3
Hook, I.
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Howell, D. A.
226e1e96-d6f6-4dc0-ac1e-0b875f105ee6
Lidman, C.
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Mitra, A.
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Möller, A.
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Mourão, A. M.
356bb8fb-5384-4b44-bae2-5650c141dd4e
Neveu, J.
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Palanque-Delabrouille, N.
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Pritchet, C. J.
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Regnault, N.
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Ruhlmann-Kleider, V.
dfecaf48-0ddc-4884-87d0-9decd4cdd029
Saunders, C.
e8f12284-5e90-4434-aafd-2a4e889f8c74
Sullivan, M.
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Roman, M.
e297a769-fc8e-4a3a-adce-927855bd6ed2
Hardin, D.
8dc08735-eba3-48aa-a7e6-e6c6a6c132da
Betoule, M.
fc9d9c60-7942-4bb4-baf4-99b7a048bae6
Astier, P.
6d36d0a2-ea1e-4fa8-8726-55add3602b5b
Balland, C.
48ce478e-1576-460d-9265-4ef9df68e4c7
Ellis, R. S.
666774eb-188f-4ec2-970f-0889a0cae5f9
Fabbro, S.
fac46460-400b-4fc6-bd93-646112d62ec7
Guy, J.
988d8cfb-8a2c-4c9c-b316-6cfa562e00a3
Hook, I.
9983ff81-9696-4753-9856-498a7ddc15b0
Howell, D. A.
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Lidman, C.
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Mitra, A.
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Möller, A.
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Mourão, A. M.
356bb8fb-5384-4b44-bae2-5650c141dd4e
Neveu, J.
1549625b-b7e7-4dbf-9745-222746347c73
Palanque-Delabrouille, N.
28861f47-e821-4f60-b871-7b122ee22385
Pritchet, C. J.
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Regnault, N.
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Ruhlmann-Kleider, V.
dfecaf48-0ddc-4884-87d0-9decd4cdd029
Saunders, C.
e8f12284-5e90-4434-aafd-2a4e889f8c74
Sullivan, M.
2f31f9fa-8e79-4b35-98e2-0cb38f503850

Roman, M., Hardin, D., Betoule, M., Astier, P., Balland, C., Ellis, R. S., Fabbro, S., Guy, J., Hook, I., Howell, D. A., Lidman, C., Mitra, A., Möller, A., Mourão, A. M., Neveu, J., Palanque-Delabrouille, N., Pritchet, C. J., Regnault, N., Ruhlmann-Kleider, V., Saunders, C. and Sullivan, M. (2018) Dependence of Type Ia supernova luminosities on their local environment. Astronomy & Astrophysics, 615. (doi:10.1051/0004-6361/201731425).

Record type: Article

Abstract

We present a fully consistent catalog of local and global properties of host galaxies of 882 Type Ia supernovæ (SNIa) that were selected based on their light-curve properties, spanning the redshift range 0.01 < z < 1. This catalog corresponds to a preliminary version of the compilation sample and includes Supernova Legacy Survey (SNLS) 5-year data, Sloan Digital Sky Survey (SDSS), and low-redshift surveys. We measured low- and moderate-redshift host galaxy photometry in SDSS stacked and single-epoch images and used spectral energy distribution fitting techniques to derive host properties such as stellar mass and U - V rest-frame colors; the latter are an indicator of the luminosity-weighted age of the stellar population in a galaxy. We combined these results with high-redshift host photometry from the SNLS survey and thus obtained a consistent catalog of host stellar masses and colors across a wide redshift range. We also estimated the local observed fluxes at the supernova location within a proper distance radius of 3 kpc, corresponding to the SNLS imaging resolution, and transposed them into local U - V rest-frame colors. This is the first time that local environments surrounding SNIa have been measured at redshifts spanning the entire Hubble diagram. Selecting SNIa based on host photometry quality, we then performed cosmological fits using local color as a third standardization variable, for which we split the sample at the median value. We find a local color step significance of - 0.091 ± 0.013 mag (7σ), which effect is as significant as the maximum mass step effect. This indicates that the remaining luminosity variations in SNIa samples can be reduced with a third standardization variable that takes the environment into account. Correcting for the maximum mass step correction of - 0.094 ± 0.013 mag, we find a local color effect of - 0.057 ± 0.012 mag (5σ), which shows that additional information is provided by the close environment of SNIa. Departures from the initial choices were investigated and showed that the local color effect is still present, although less pronounced. We discuss the possible implications for cosmology and find that using the local color in place of the stellar mass results in a change in the measured value of the dark energy equation-of-state parameter of 0.6%. Standardization using local U - V color in addition to stretch and color reduces the total dispersion in the Hubble diagram from 0.15 to 0.14 mag. This will be of tremendous importance for the forthcoming SNIa surveys, and in particular for the Large Synoptic Survey Telescope (LSST), for which uncertainties on the dark energy equation of state will be comparable to the effects reported here.

Full text not available from this repository.

More information

Accepted/In Press date: 30 January 2018
e-pub ahead of print date: 16 July 2018
Published date: July 2018
Keywords: Dark energy, Galaxies: photometry, Methods: data analysis, Supernovae: general, Techniques: image processing, Techniques: photometric

Identifiers

Local EPrints ID: 424939
URI: https://eprints.soton.ac.uk/id/eprint/424939
ISSN: 0004-6361
PURE UUID: 73c950a5-c151-4802-bb16-206110535158
ORCID for M. Sullivan: ORCID iD orcid.org/0000-0001-9053-4820

Catalogue record

Date deposited: 05 Oct 2018 16:30
Last modified: 17 Jul 2019 17:07

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Contributors

Author: M. Roman
Author: D. Hardin
Author: M. Betoule
Author: P. Astier
Author: C. Balland
Author: R. S. Ellis
Author: S. Fabbro
Author: J. Guy
Author: I. Hook
Author: D. A. Howell
Author: C. Lidman
Author: A. Mitra
Author: A. Möller
Author: A. M. Mourão
Author: J. Neveu
Author: N. Palanque-Delabrouille
Author: C. J. Pritchet
Author: N. Regnault
Author: V. Ruhlmann-Kleider
Author: C. Saunders
Author: M. Sullivan ORCID iD

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