Euclid preparation : XI. Mean redshift determination from galaxy redshift probabilities for cosmic shear tomography
Euclid Collaboration. (2021). Euclid preparation : XI. Mean redshift determination from galaxy redshift probabilities for cosmic shear tomography. Astronomy and Astrophysics, 647, Article A117. https://doi.org/10.1051/0004-6361/202040237
Julkaistu sarjassa
Astronomy and AstrophysicsTekijät
Päivämäärä
2021Tekijänoikeudet
© Euclid Collaboration 2021
The analysis of weak gravitational lensing in wide-field imaging surveys is considered to be a major cosmological probe of dark energy. Our capacity to constrain the dark energy equation of state relies on an accurate knowledge of the galaxy mean redshift ⟨z⟩. We investigate the possibility of measuring ⟨z⟩ with an accuracy better than 0.002 (1 + z) in ten tomographic bins spanning the redshift interval 0.2 < z < 2.2, the requirements for the cosmic shear analysis of Euclid. We implement a sufficiently realistic simulation in order to understand the advantages and complementarity, as well as the shortcomings, of two standard approaches: the direct calibration of ⟨z⟩ with a dedicated spectroscopic sample and the combination of the photometric redshift probability distribution functions (zPDFs) of individual galaxies. We base our study on the Horizon-AGN hydrodynamical simulation, which we analyse with a standard galaxy spectral energy distribution template-fitting code. Such a procedure produces photometric redshifts with realistic biases, precisions, and failure rates. We find that the current Euclid design for direct calibration is sufficiently robust to reach the requirement on the mean redshift, provided that the purity level of the spectroscopic sample is maintained at an extremely high level of > 99.8%. The zPDF approach can also be successful if the zPDF is de-biased using a spectroscopic training sample. This approach requires deep imaging data but is weakly sensitive to spectroscopic redshift failures in the training sample. We improve the de-biasing method and confirm our finding by applying it to real-world weak-lensing datasets (COSMOS and KiDS+VIKING-450).
...
![showless](/themes/JYX2//images/showless.png)
![showmore](/themes/JYX2//images/showmore.png)
Julkaisija
EDP SciencesISSN Hae Julkaisufoorumista
0004-6361Asiasanat
Julkaisu tutkimustietojärjestelmässä
https://converis.jyu.fi/converis/portal/detail/Publication/66440738
Metadata
Näytä kaikki kuvailutiedotKokoelmat
Lisenssi
Samankaltainen aineisto
Näytetään aineistoja, joilla on samankaltainen nimeke tai asiasanat.
-
Euclid preparation : XVII. Cosmic Dawn Survey : Spitzer Space Telescope observations of the Euclid deep fields and calibration fields
Euclid Collaboration (EDP Sciences, 2022)We present a new infrared survey covering the three Euclid deep fields and four other Euclid calibration fields using Spitzer Space Telescope’s Infrared Array Camera (IRAC). We combined these new observations with all ... -
Euclid preparation : XIII. Forecasts for galaxy morphology with the Euclid Survey using deep generative models
Euclid Collaboration (EDP Sciences, 2022)We present a machine learning framework to simulate realistic galaxies for the Euclid Survey, producing more complex and realistic galaxies than the analytical simulations currently used in Euclid. The proposed method ... -
Euclid preparation : XXII. Selection of quiescent galaxies from mock photometry using machine learning
Euclid Collaboration (EDP Sciences, 2023)The Euclid Space Telescope will provide deep imaging at optical and near-infrared wavelengths, along with slitless near-infrared spectroscopy, across ~15 000deg2 of the sky. Euclid is expected to detect ~12 billion ... -
Euclid preparation : XV. Forecasting cosmological constraints for the Euclid and CMB joint analysis
Euclid Collaboration (EDP Sciences, 2022)The combination and cross-correlation of the upcoming Euclid data with cosmic microwave background (CMB) measurements is a source of great expectation since it will provide the largest lever arm of epochs, ranging from ... -
Euclid preparation : XX. The Complete Calibration of the Color–Redshift Relation survey : LBT observations and data release
Euclid Collaboration (EDP Sciences, 2022)The Complete Calibration of the Color–Redshift Relation survey (C3R2) is a spectroscopic program designed to empirically calibrate the galaxy color–redshift relation to the Euclid depth (IE = 24.5), a key ingredient for ...
Ellei toisin mainittu, julkisesti saatavilla olevia JYX-metatietoja (poislukien tiivistelmät) saa vapaasti uudelleenkäyttää CC0-lisenssillä.