We perform an analysis of the recent WMAP7 data considering physically motivated and viable reionization scenarios with the aim of assessing their effects on cosmological parameter determinations .
The main novelties are : ( i ) the combination of CMB data with astrophysical results from quasar absorption line experiments ; ( ii ) the joint variation of both the cosmological and astrophysical [ governing the evolution of the free electron fraction x _ { e } ( z ) ] parameters .
Including a realistic , data-constrained reionization history in the analysis induces appreciable changes in the cosmological parameter values deduced through a standard WMAP7 analysis .
Particularly noteworthy are the variations in \Omega _ { b } h ^ { 2 } = 0.02258 ^ { +0.00057 } _ { -0.00056 } ( WMAP7 ) vs . \Omega _ { b } h ^ { 2 } = 0.02183 \pm 0.00054 ( WMAP7 + ASTRO ) , and the new constraints for the scalar spectral index , for which WMAP7 + ASTRO excludes the Harrison-Zel ’ dovich value n _ { s } = 1 at > 3 \sigma .
Finally , the e.s .
optical depth value is considerably decreased with respect to the standard WMAP7 , i.e . \tau _ { e } = 0.080 \pm 0.012 .
We conclude that the inclusion of astrophysical datasets , allowing to robustly constrain the reionization history , in the extraction procedure of cosmological parameters leads to relatively important differences in the final determination of their values .