Simulating JWST deep extragalactic imaging surveys and physical
  parameter recovery
  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 $\sim300,000$ 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 $z\leq7$ 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.
