The University of Southampton
University of Southampton Institutional Repository

Dark Energy Survey Year 1 results: Cross-correlation redshifts - methods and systematics characterization

Dark Energy Survey Year 1 results: Cross-correlation redshifts - methods and systematics characterization
Dark Energy Survey Year 1 results: Cross-correlation redshifts - methods and systematics characterization

We use numerical simulations to characterize the performance of a clustering-based method to calibrate photometric redshift biases. In particular, we cross-correlate the weak lensing source galaxies from the Dark Energy Survey Year 1 sample with redMaGiC galaxies (luminous red galaxies with secure photometric redshifts) to estimate the redshift distribution of the former sample. The recovered redshift distributions are used to calibrate the photometric redshift bias of standard photo-z methods applied to the same source galaxy sample.We apply the method to two photo-z codes run in our simulated data: Bayesian Photometric Redshift and Directional Neighbourhood Fitting. We characterize the systematic uncertainties of our calibration procedure, and find that these systematic uncertainties dominate our error budget. The dominant systematics are due to our assumption of unevolving bias and clustering across each redshift bin, and to differences between the shapes of the redshift distributions derived by clustering versus photo-zs. The systematic uncertainty in the mean redshift bias of the source galaxy sample is Δz ≲ 0.02, though the precise value depends on the redshift bin under consideration. We discuss possible ways to mitigate the impact of our dominant systematics in future analyses.

Cosmology: Observations, Galaxies: Distances and redshifts
1365-2966
1664-1682
Gatti, M.
be9e1f3e-3cb4-4cc3-9d64-01bc9547d290
Vielzeuf, P.
58cb7cf8-d759-4879-85b6-f3a1a13615a9
Cawthon, R.
511746c8-55f1-4877-b481-d6b6488030e9
Rau, M.M.
2eff1a56-e334-4e07-a156-69d034b6205b
DeRose, J.
0e595bcc-0c8b-4d69-9845-83ab92a229f7
De Vicente, J.
f1d6022a-1d82-4b26-b421-4627aa5a5568
Alarcon, A.
df0b9a08-759b-4a6b-ad40-5e4c2406e984
Rozo, E.
9008ecfe-f138-4c4c-a88b-09c32549f7c4
Gaztanaga, E.
3a3f63dd-9666-448c-9ec6-10e53fc0dc1a
Hoyle, B.
fdc773d9-a7f6-45a5-8572-c195bc6b414c
Miquel, R.
acd92fc5-f50f-4ae0-afe8-01db537b6e36
Bernstein, G. M.
9d12d964-5827-488e-9de3-c4b0b517e8aa
Bonnett, C.
7d27b53e-cb7f-4451-85c2-10b97f02fe49
Rosell, A. Carnero
d66191ef-a014-4029-bfe8-e9b3c653e3be
Castander, F.J.
b61356c2-f7f5-4da7-9322-b9eda0b0081a
Chang, C.
dd7aac7e-3325-4649-a6c5-06a9fa439666
da Costa, L.N.
b1ed9fd9-b99a-4012-8112-79cba46d8a23
Gruen, D.
8d960f6a-1219-4ce1-9312-616e463616eb
Gschwend, J.
cfbbfd77-feea-4e19-91b7-f40b8969f453
Hartley, W.G.
f8388551-09ca-4c65-88ea-e0f5d9090d2d
Lin, H.
703a582c-0cd8-4724-9072-b7e1241fae63
MacCrann, N.
c0bfddf4-8911-4f7d-bfb3-65e1f7f976cf
Maia, M.A.G.
98ea0959-ba94-454f-b826-a589acf2297c
Ogando, R.L.C.
2af3ab81-7deb-456f-bce7-67ade23683d3
Roodman, A.
e4b6b3b1-7c56-4112-b281-2f63b38e99d5
Sevilla-Noarbe, I.
a4690b61-feca-4933-887c-121a9f343470
Troxel, M. A.
98179534-4eec-4118-9883-713aef806609
Wechsler, R.H.
b9ffbfa5-0c52-46fb-b570-bde2c89f4340
Asorey, J.
c8481389-854f-41ed-9fa5-adcb64ed8be7
Davis, T.M.
466dfec4-c506-41fb-8b23-ea6c3c97e15b
Glazebrook, K.
a0f7c538-1e8c-4ea8-9f49-a5ab0eb353f4
Hinton, S.R.
9e2f00d6-7026-4491-a28e-17d5880f65d1
Lewis, G.
7a7b9fa6-bb3c-4a5e-83ec-648e272ec873
Lidman, C.
70c80609-d55e-4ca6-b057-aed4a00b4b89
Macaulay, E.
2f5ea6e5-aede-431a-8ea9-9a79cf4d39b5
Möller, A.
64e6f7fe-41ac-498b-9f69-c88a0f7981c4
O'Neill, C.R.
bb6d9cdc-2f15-4ca9-9e53-c6f99f95dc65
Sommer, N.E.
d60a6dac-111c-44a1-8933-c22e20d410bd
Uddin, S.A.
b9c7578a-d64b-4852-80e5-c53d7fb8230b
Yuan, F.
b14622a1-ebc8-428b-85e1-72881fb8bfa6
Zhang, B.
097d9ce6-3714-4961-9b27-e5934aada287
Abbott, T.M.C.
6afa6308-fd36-4189-aef0-d86c784311d9
Allam, S.
0355ab50-73f1-493b-80dc-86c4d4422bee
Annis, J.
b21af104-dcad-472a-8424-b49d41d41c06
Bechtol, K.
196af8f4-f0d6-4e85-9d03-7259b7210b23
Brooks, D.
a3c528d9-fb8a-406c-bc92-56eff4985bcf
Burke, D.L.
0d20fba0-9285-4cb4-b076-312166fc7ad7
Carollo, D.
a1aaebdc-b44f-4397-9a39-8e1ce3ba0fa5
D'Andrea, C.B.
4befc380-f47c-49cc-a84e-2e2d2ac14edd
Smith, M.
8bdc74e1-a37b-434d-ae75-82763109bf7a
The DES Collaboration
Gatti, M.
be9e1f3e-3cb4-4cc3-9d64-01bc9547d290
Vielzeuf, P.
58cb7cf8-d759-4879-85b6-f3a1a13615a9
Cawthon, R.
511746c8-55f1-4877-b481-d6b6488030e9
Rau, M.M.
2eff1a56-e334-4e07-a156-69d034b6205b
DeRose, J.
0e595bcc-0c8b-4d69-9845-83ab92a229f7
De Vicente, J.
f1d6022a-1d82-4b26-b421-4627aa5a5568
Alarcon, A.
df0b9a08-759b-4a6b-ad40-5e4c2406e984
Rozo, E.
9008ecfe-f138-4c4c-a88b-09c32549f7c4
Gaztanaga, E.
3a3f63dd-9666-448c-9ec6-10e53fc0dc1a
Hoyle, B.
fdc773d9-a7f6-45a5-8572-c195bc6b414c
Miquel, R.
acd92fc5-f50f-4ae0-afe8-01db537b6e36
Bernstein, G. M.
9d12d964-5827-488e-9de3-c4b0b517e8aa
Bonnett, C.
7d27b53e-cb7f-4451-85c2-10b97f02fe49
Rosell, A. Carnero
d66191ef-a014-4029-bfe8-e9b3c653e3be
Castander, F.J.
b61356c2-f7f5-4da7-9322-b9eda0b0081a
Chang, C.
dd7aac7e-3325-4649-a6c5-06a9fa439666
da Costa, L.N.
b1ed9fd9-b99a-4012-8112-79cba46d8a23
Gruen, D.
8d960f6a-1219-4ce1-9312-616e463616eb
Gschwend, J.
cfbbfd77-feea-4e19-91b7-f40b8969f453
Hartley, W.G.
f8388551-09ca-4c65-88ea-e0f5d9090d2d
Lin, H.
703a582c-0cd8-4724-9072-b7e1241fae63
MacCrann, N.
c0bfddf4-8911-4f7d-bfb3-65e1f7f976cf
Maia, M.A.G.
98ea0959-ba94-454f-b826-a589acf2297c
Ogando, R.L.C.
2af3ab81-7deb-456f-bce7-67ade23683d3
Roodman, A.
e4b6b3b1-7c56-4112-b281-2f63b38e99d5
Sevilla-Noarbe, I.
a4690b61-feca-4933-887c-121a9f343470
Troxel, M. A.
98179534-4eec-4118-9883-713aef806609
Wechsler, R.H.
b9ffbfa5-0c52-46fb-b570-bde2c89f4340
Asorey, J.
c8481389-854f-41ed-9fa5-adcb64ed8be7
Davis, T.M.
466dfec4-c506-41fb-8b23-ea6c3c97e15b
Glazebrook, K.
a0f7c538-1e8c-4ea8-9f49-a5ab0eb353f4
Hinton, S.R.
9e2f00d6-7026-4491-a28e-17d5880f65d1
Lewis, G.
7a7b9fa6-bb3c-4a5e-83ec-648e272ec873
Lidman, C.
70c80609-d55e-4ca6-b057-aed4a00b4b89
Macaulay, E.
2f5ea6e5-aede-431a-8ea9-9a79cf4d39b5
Möller, A.
64e6f7fe-41ac-498b-9f69-c88a0f7981c4
O'Neill, C.R.
bb6d9cdc-2f15-4ca9-9e53-c6f99f95dc65
Sommer, N.E.
d60a6dac-111c-44a1-8933-c22e20d410bd
Uddin, S.A.
b9c7578a-d64b-4852-80e5-c53d7fb8230b
Yuan, F.
b14622a1-ebc8-428b-85e1-72881fb8bfa6
Zhang, B.
097d9ce6-3714-4961-9b27-e5934aada287
Abbott, T.M.C.
6afa6308-fd36-4189-aef0-d86c784311d9
Allam, S.
0355ab50-73f1-493b-80dc-86c4d4422bee
Annis, J.
b21af104-dcad-472a-8424-b49d41d41c06
Bechtol, K.
196af8f4-f0d6-4e85-9d03-7259b7210b23
Brooks, D.
a3c528d9-fb8a-406c-bc92-56eff4985bcf
Burke, D.L.
0d20fba0-9285-4cb4-b076-312166fc7ad7
Carollo, D.
a1aaebdc-b44f-4397-9a39-8e1ce3ba0fa5
D'Andrea, C.B.
4befc380-f47c-49cc-a84e-2e2d2ac14edd
Smith, M.
8bdc74e1-a37b-434d-ae75-82763109bf7a

Smith, M. , The DES Collaboration (2018) Dark Energy Survey Year 1 results: Cross-correlation redshifts - methods and systematics characterization. Monthly Notices of the Royal Astronomical Society, 477 (2), 1664-1682. (doi:10.1093/mnras/sty466).

Record type: Article

Abstract

We use numerical simulations to characterize the performance of a clustering-based method to calibrate photometric redshift biases. In particular, we cross-correlate the weak lensing source galaxies from the Dark Energy Survey Year 1 sample with redMaGiC galaxies (luminous red galaxies with secure photometric redshifts) to estimate the redshift distribution of the former sample. The recovered redshift distributions are used to calibrate the photometric redshift bias of standard photo-z methods applied to the same source galaxy sample.We apply the method to two photo-z codes run in our simulated data: Bayesian Photometric Redshift and Directional Neighbourhood Fitting. We characterize the systematic uncertainties of our calibration procedure, and find that these systematic uncertainties dominate our error budget. The dominant systematics are due to our assumption of unevolving bias and clustering across each redshift bin, and to differences between the shapes of the redshift distributions derived by clustering versus photo-zs. The systematic uncertainty in the mean redshift bias of the source galaxy sample is Δz ≲ 0.02, though the precise value depends on the redshift bin under consideration. We discuss possible ways to mitigate the impact of our dominant systematics in future analyses.

This record has no associated files available for download.

More information

e-pub ahead of print date: 22 February 2018
Published date: 21 June 2018
Keywords: Cosmology: Observations, Galaxies: Distances and redshifts

Identifiers

Local EPrints ID: 423361
URI: http://eprints.soton.ac.uk/id/eprint/423361
ISSN: 1365-2966
PURE UUID: 0097828e-bcd8-4b43-b2e8-cd8e66a83ad6
ORCID for M. Smith: ORCID iD orcid.org/0000-0002-3321-1432

Catalogue record

Date deposited: 20 Sep 2018 16:30
Last modified: 12 Nov 2024 02:50

Export record

Altmetrics

Contributors

Author: M. Gatti
Author: P. Vielzeuf
Author: R. Cawthon
Author: M.M. Rau
Author: J. DeRose
Author: J. De Vicente
Author: A. Alarcon
Author: E. Rozo
Author: E. Gaztanaga
Author: B. Hoyle
Author: R. Miquel
Author: G. M. Bernstein
Author: C. Bonnett
Author: A. Carnero Rosell
Author: F.J. Castander
Author: C. Chang
Author: L.N. da Costa
Author: D. Gruen
Author: J. Gschwend
Author: W.G. Hartley
Author: H. Lin
Author: N. MacCrann
Author: M.A.G. Maia
Author: R.L.C. Ogando
Author: A. Roodman
Author: I. Sevilla-Noarbe
Author: M. A. Troxel
Author: R.H. Wechsler
Author: J. Asorey
Author: T.M. Davis
Author: K. Glazebrook
Author: S.R. Hinton
Author: G. Lewis
Author: C. Lidman
Author: E. Macaulay
Author: A. Möller
Author: C.R. O'Neill
Author: N.E. Sommer
Author: S.A. Uddin
Author: F. Yuan
Author: B. Zhang
Author: T.M.C. Abbott
Author: S. Allam
Author: J. Annis
Author: K. Bechtol
Author: D. Brooks
Author: D.L. Burke
Author: D. Carollo
Author: C.B. D'Andrea
Author: M. Smith ORCID iD
Corporate Author: The DES Collaboration

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×