We produce simulations of the atomic CII line emission in large sky fields in order to determine the current and future prospects for mapping this line during the high redshift epoch of reionization .
We calculate the CII line intensity , redshift evolution and spatial fluctuations using observational relations between CII emission and the galaxy star formation rate ( SFR ) over the frequency range 200 - 300 GHz .
We estimate an averaged intensity of { I _ { CII } = ( 4 \pm 2 ) \times 10 ^ { 2 } Jy sr ^ { -1 } } in the redshift range z \sim 5.3 - 8.5 .
Observations of the CII emission in this frequency range will suffer contamination from emission lines at lower redshifts , in particular CO rotational lines .
Using simulations , we estimated the CO contamination to be { I _ { CO } \approx 10 ^ { 3 } Jy sr ^ { -1 } } ( originating from galaxies at z < 2.5 ) .
Using detailed simulations of the CII and CO emission across a range of redshifts , we generate maps as a function of angle and frequency , fully taking into account this resolution and light cone effects .
In order to reduce the foreground contamination we find that we should mask galaxies below redshifts \sim 2.5 with a CO ( J:2-1 ) to CO ( J:6-5 ) line flux density higher than { 5 \times 10 ^ { -22 } W m ^ { -2 } } or a AB magnitude lower than { m _ { K } = 22 } .
We estimate that the additional continuum contamination originating in emission from stars and in dust , free-free , free-bound and two photon emission in the ISM is of the order of { 10 ^ { 5 } Jy sr ^ { -1 } } however it can be removed from observation due to the smooth evolution of this foreground with frequency .
We also consider the possibility of cross correlating foreground lines with galaxy surveys in order to probe the intensity of the foregrounds .
Finally , we discuss the expected constraints from two experiments capable of measuring the expected CII power spectrum .