COSMIC SHEAR · Cosmic Shear Analysis of the Kilo Degree Survey: Cosmological Constraints
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2016-01-20 → 2018-01-19
- EU contribution
- €195,455
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Cosmic Shear Analysis of the Kilo Degree Survey: Cosmological Constraints
'Dark matter' and 'dark energy' are arguably the most mysterious substances in our Universe. Using the technique of weak gravitational lensing, we are beginning to understand many of their properties, including their time evolution, their reaction under gravity, and their relation to observable galaxies. In summary, light coming from distant galaxies is distorted in the presence of dark matter, in excellent analogy with the way a normal lens distorts the shape of background images. By measuring the coherence in these distortions as a function of time and space, we are able to construct maps of dark matter at different epochs. Analysing the images of millions of galaxies recorded for the Kilo Degree Survey by the European Southern Observatory, we observe that the clustering of dark matter evolves with time, and that it tends to live in haloes whose shapes, profiles and mass we can now measure. By understanding these properties, we construct a clearer picture of what constitutes about 85% of the mass in our Universe. Over the course of this action, I have combined the measurement of these shapes with the microwave observation from the Planck satellites and placed independent constraints on the abundance and clustering of dark matter in five time snapshots, which allowed me to further investigate its growth. I have additionally constructed a massive state-of-the-art control sample of simulated galaxy catalogues and dark matter maps that allowed our international team to validate, test and calibrate our tools and results. This mock data has been used in a number of analyses thus far - more than 20 published papers- and consists in a key legacy that will take us through the next decade.
Data: CORDIS, © European Union
Project objective
Weak gravitational lensing is one of the most promising techniques for probing and mapping the dark matter distribution within our Universe. Using lensing, we can simultaneously measure the total mass, the number of neutrino species and the global acceleration of the cosmic expansion, offering a direct handle on the mysterious dark energy. This Marie Sklodowska-Curie action will carry out one of the most competitive cosmological analyses to date by measuring cosmic shear from the weak lensing data acquired by the state-of-the-art European Southern Observatory Kilo Degree Survey (KiDS). We will place tight constraints on the theoretical parameters that describe the dark Universe. In addition, this analysis has the potential to reveal which galactic baryonic processes, between active galactic nuclei, sustained stellar winds or supernovae bursts, effectively feedback on the total matter density field.This scientific programme is central to an international collaboration that brings together the Fellow's expertise in theoretical and numerical modelling with world class experts on image processing, galaxy shape and distance estimation, weak lensing calibration and interpretation. The Fellow will analyze the KiDS data to its full potential by employing new methodology and including key ingredients to the analysis, for which his numerical simulations and mock galaxy catalogues are critical. Combined with innovative approaches in the treatment of the astrophysical and systematic uncertainties in weak lensing analyses, the project will guarantee a high level of precision and robustness in the resulting cosmological parameter constraints.
Original text from CORDIS.
Participants
- THE UNIVERSITY OF EDINBURGH · EdinburghCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union