Quasar microlensing serves as a unique probe of discrete objects within galaxies and galaxy clusters .
Recent advancement of the technique shows that it can constrain planet-scale objects beyond our native galaxy by studying their induced microlensing signatures , the energy shift of emission lines originated in the vicinity of the black hole of high redshift background quasars .
We employ this technique to exert effective constraints on the planet-mass object distribution within two additional lens systems , Q J0158 - 4325 ( z _ { l } = 0.317 ) and SDSS J1004+4112 ( z _ { l } = 0.68 ) using Chandra observations of the two gravitationally-lensed quasars .
The observed variations of the emission line peak energy can be explained as microlensing of the FeK \alpha emission region induced by planet-mass microlenses .
To corroborate this , we perform microlensing simulations to determine the probability of a caustic transiting the source region and compare this with the observed line shift rates .
Our analysis yields constraints on the sub-stellar population , with masses ranging from Moon ( 10 ^ { -8 } M _ { \odot } ) to Jupiter ( 10 ^ { -3 } M _ { \odot } ) sized bodies , within these galaxy or cluster scale structures , with total mass fractions of \sim 3 \times 10 ^ { -4 } and \sim 1 \times 10 ^ { -4 } with respect to halo mass for Q J0158 - 4325 and SDSS J1004+4112 , respectively .
Our analysis suggests that unbound planet-mass objects are universal in galaxies , and we surmise the objects to be either free-floating planets or primordial black holes .
We present the first-ever constraints on the sub-stellar mass distribution in the intra-cluster light of a galaxy cluster .
Our analysis yields the most stringent limit for primordial black holes at the mass range .