Presentation #343.15 in the session Potpourri of Galaxies — iPoster Session.
Due to their high luminosity and abundance out to high redshifts, quasars readily present themselves as ideal candidates for cosmological probes. Despite numerous attempts to quantify a relationship intrinsic to quasars to build the Hubble Diagram, previous studies have suffered from a high dispersion when probing the cosmological parameters. Risaliti & Lusso 2015 proposed a new method of using the quasars non-linear relation between UV and X-ray luminosities to independently build a Hubble diagram up to z~6, thus testing cosmological models and constraining the cosmological parameters. In this presentation, I will introduce our most recent efforts, as part of Chandra Cool Target (CCT) projects to further decrease the dispersion in the quasar X-ray and UV luminosity relation, which covers a detailed analysis of ~30 quasars, with the results providing further insight into how we can better tailor our source selection process to minimise dispersion in addition to teaching us more about the physics of quasars.