| Grant number: | 16/17271-5 |
| Support Opportunities: | Scholarships abroad - Research Internship - Post-doctor |
| Start date: | January 16, 2017 |
| End date: | January 15, 2018 |
| Field of knowledge: | Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics |
| Principal Investigator: | Marcos Vinicius Borges Teixeira Lima |
| Grantee: | Vinicius Consolini Busti |
| Supervisor: | Bhuvnesh Jain |
| Host Institution: | Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil |
| Institution abroad: | University of Pennsylvania, United States |
| Associated to the scholarship: | 14/21098-1 - Precision cosmology with the Dark Energy Survey, BP.PD |
Abstract Galaxy clusters probe the high-end limit of the halo mass function, where their abundance is very sensitive to how structures formed in the Universe and therefore to cosmological parameters. In order to take full advantage of these objects, one must connect the observed cluster richness, i.e. the number of galaxies in a cluster, with the mass of the halo where the cluster resides. This is known as the mass-richness relation. Its measurement or calibration is paramount to derive robust cosmological constraints and constitutes the main goal of this project. We shall use the high-redshift coverage (z ~ 1) and wide area (5,000 deg squared) of the Dark Energy Survey (DES) to calibrate the mass-richness relation and use it to derive the most stringent limits on cosmological parameters from optical galaxy clusters. Three different methods will be used to calibrate the mass-richness relation, using the angular correlation function of galaxy clusters, the projected correlation function of galaxy clusters and the weak lensing effect that galaxy clusters induce on background galaxies. Each method possesses its own systematic errors, which will be characterized, allowing for a comparison of the multiple results. All the methods will be carefully validated through simulations provided by DES, first in the dark matter halos and then for galaxy clusters detected in simulations, hence allowing us to understand the cluster finder properties. Finally, the methods will be applied on the data from the first year (Y1) and second/third years (Y3) releases, with the aim of obtaining constraints to the mass-richness relation and a thorough understanding of the analysis, which will pave the way for the Y5 final data release and future surveys. (AU) | |
| News published in Agência FAPESP Newsletter about the scholarship: | |
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