PRIN 2022: PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE

                               Prot. 2022KCS97B - CUP: J53D23001620006                                      

Research Unit 1: Matteo Costanzi (UniTs) - finanziamento 139.050 Euro di cui 125.644 Euro di contributo MUR

Research Unit 2: Emiliano Munari (INAF-Trieste) - CUP C53D23001140006 - finanziamento 122.836 euro di cui 98.779 euro di contributo MUR

Galaxy clusters are one of the main cosmological probes of the next coming wide field photometric surveys, such as Euclid or LSST, with the promise of helping shedding light on many fundamental questions in cosmology such as the nature of dark matter and dark energy.

Yet, despite the huge progress made over the last decade, a sizable amount of the cosmological information encoded in this data risks to remain unexploited due to our limited capability of connecting the observed properties of the large scale structure to our theoretical models.

Photometric cluster catalogs exemplify this limitation: different sources of systematics hamper our capability of calibrating cluster masses from observable mass proxies, and thus, of interpreting the data within our theoretical framework. This is especially true for low to intermediate mass systems (13.5≲log(M)≲14.5): these objects outnumber by orders of magnitudes the number of massive clusters in photometric cluster catalogs, but the low signal-to-noise (S/N) of these detections makes these systems especially prone to systematics which hinder their cosmological utility.

The EMC2 proposal aims at unlocking the full cosmological utility of the forthcoming Euclid cluster catalog by a careful characterization of the sample over the whole mass range probed by the survey with particular emphasis on the poorly understood low S/N detections which limit the statistical power of ongoing and future photometric cluster surveys. 

We plan to achieve our goal by pursuing three main lines of investigation:

1) the optimization of the cluster finder algorithms and mass proxy definition used to build the cosmological sample;

2) the development of a model to accurately describe the relation between the photometric mass proxies and underlying halo mass over the whole mass range probed by the survey;

3) the development of a methodology to optimally exploit the sparse cluster member galaxies’ spectroscopic data that will be available from the Euclid survey for cluster mass calibration.

Publications:

• Costanzi et al in prep

• Ingrao et al in prep

• Fumagalli et al 

Outreach