Speaker
Description
The damping wing signatures in high-redshift quasars have proven instrumental in studying the epoch of reionization. With the upcoming Euclid mission set to discover many more quasars, it is crucial to explore what this new set of quasars might reveal not only about the reionization history but also its topology. The reionization topology near the epoch depends on several parameters, including the global neutral fraction, $\mathrm{x_{HI}}$, the minimum mass that can support star formation, $\mathrm{M_{min}}$, the quasar lifetime, $\mathrm{t_{q}}$, and the mass of the quasar's host halo, $\mathrm{M_{qso}}$. We studied the effect of these parameters on reionization topology as a function of the median damping wing profile, the sightline-to-sightline scatter $\Delta SW_{68}$, and their combination for a set of quasar spectra. We derived the constraints on the abovementioned parameters using the Fisher matrix. The constraints provided by only $\mathrm{64}$ quasars at redshift $\mathrm{7}$, $\mathrm{x_{HI} = 0.5^{+0.02}_{-0.02}} $, $\mathrm{M_{min} = 8.78^{+0.53}_{-0.53} }$, $\mathrm{\log{t_{q}/yr}= 6.0^{+0.12}_{-0.12}}$, and $ \mathrm{\log{M_{qso}/ M_\odot}= 11.52^{+0.32}_{-0.31}}$ are comparable to the results from other observables like 21cm signal. We also investigated the dependencies of these constraints as a function of the number of quasars, spectral noise, and continuum noise. We also looked at the changes in the nature of these constraints at multiple redshifts and luminosities of the sources. We found that the overall constraints on $\mathrm{x_{HI}}$, $\mathrm{t_{q}}$, and $\mathrm{M_{min}}$ improve when we lower the redshift or examine the fainter sources due to the decreasing effects of proximity zones.
