We present a new prospective analysis of deep multi-band imaging with the James Webb Space Telescope ( JWST ) .
In this work , we investigate the recovery of high-redshift 5 < z < 12 galaxies through extensive image simulations of accepted JWST programs such as CEERS in the EGS field and HUDF GTO .
We introduce complete samples of \sim 300,000 galaxies with stellar masses \log ( M _ { * } / M _ { \odot } ) > 6 and redshifts 0 < z < 15 , as well as galactic stars , into realistic mock NIRCam , MIRI and HST images to properly describe the impact of source blending .
We extract the photometry of the detected sources as in real images and estimate the physical properties of galaxies through spectral energy distribution fitting .
We find that the photometric redshifts are primarily limited by the availability of blue-band and near-infrared medium-band imaging .
The stellar masses and star-formation rates are recovered within 0.25 and 0.3 dex respectively , for galaxies with accurate photometric redshifts .
Brown dwarfs contaminating the z > 5 galaxy samples can be reduced to < 0.01 arcmin ^ { -2 } with a limited impact on galaxy completeness .
We investigate multiple high-redshift galaxy selection techniques and find the best compromise between completeness and purity at 5 < z < 10 using the full redshift posterior probability distributions .
In the EGS field , the galaxy completeness remains higher than 50 \% for m _ { \text { UV } } < 27.5 sources at all redshifts , and the purity is maintained above 80 and 60 % at z \leq 7 and 10 respectively .
The faint-end slope of the galaxy UV luminosity function is recovered with a precision of 0.1-0.25 , and the cosmic star-formation rate density within 0.1 dex .
We argue in favor of additional observing programs covering larger areas to better constrain the bright end .