The birefringent effects of photon-pseudoscalar boson ( Goldstone ) particle mixing in intergalactic magnetic field are calculated for cosmological objects .
We use the recent results of PVLAS collaboration that reported recently the observation of a rotation of the polarization plane of light propagating through a transverse static magnetic field .
Such results which were interpretated as arising due to conversion of photon into pseudoscalar with coupling strength g _ { a \gamma } \sim 4 \times 10 ^ { -6 } GeV ^ { -1 } allows us to estimate the intergalactic magnetic field magnitude as \sim 10 ^ { -16 } G based on Hatsemekers et al .
observations of extreme-scale alignments of quasar polarization vectors .
We have analyzed some additional results of astronomical observations that could be explained by axion interpretation of the PVLAS data : a sharp steepening of the QSO continuum short ward of \simeq 1100 Å , observed circular polarization of AGNs and QSOs , discrepancy between observed intrinsic polarization of stars in the Local Bubble and stellar spectral classification .
The observed polarization of stars in the Local Bubble can ’ t be explained by interstellar origin .

Key words : polarization , axion , quasar , intergalactic magnetic field .