Wavelength-resolved Reverberation Mapping of quasar CTSC30.10: Dissecting MgII and FeII emission regions

Our long-term goal is to use quasar to measure the Hubble constant in order to prove or disprove the Hubble Tension. We aim to use the independent measurement of Radius-Luminosity relation in quasar for cosmological purposes. However, one of the best know emission lines that can be used is MgII. Even though the emission line is very broad and well-measured sometimes it is contaminated by the pseudo-FeII emission. I will present our recent work where we try to disentangle the MgII and FeII emission regions before using the MgII emission line to standardize the quasars for cosmology. We have monitored the bright quasar CTS C30.10 with SALT for the last 10 years and we study the wavelength-resolved reverberation to achieve the intrinsic time lag of MgII which can be further used for Radius-Luminosity relation and eventually for cosmology. We also proposed the radius-luminosity relation for the FeII emission first time ever and we believe in the future this can also be used as an independent tool to measure the H0.