Photoionized Herbig-Haro objects in the Orion Nebula through deep
  high-spectral resolution spectroscopy III: HH514
  We analyze the physical conditions and chemical composition of the
photoionized Herbig-Haro object HH~514, which emerges from the proplyd 170-337
in the core of the Orion Nebula. We use high-spectral resolution spectroscopy
from UVES at the Very Large Telescope and IFU-spectra from MEGARA at the Gran
Telescopio de Canarias. We observe two components of HH~514, the jet base and a
knot, with $n_{\rm e}= (2.3 \pm 0.1) \times 10^5 \text{cm}^{-3}$ and $n_{\rm
e}= (7 \pm 1) \times 10^4 \text{cm}^{-3}$, respectively, both with $T_{\rm
e}\approx 9000 \text{ K}$. We show that the chemical composition of HH~514 is
consistent with that of the Orion Nebula, except for Fe, Ni and S, which show
higher abundances. The enhanced abundances of Fe and Ni observed in HH objects
compared with the general interstellar medium is usually interpreted as
destruction of dust grains. The observed sulphur overabundance (more than two
times solar) is challenging to explain since the proplyd photoevaporation flow
from the same disk shows normal sulphur abundance. If the aforementioned
S-overabundance is due to dust destruction, the formation of sulfides and/or
other S-bearing dust reservoirs may be linked to planet formation processes in
protoplanetary disks, which filter large sulfide dust grains during the
accretion of matter from the disk to the central star. We also show that
published kinematics of molecular emission close to the central star are not
consistent with either a disk perpendicular to the optical jet, nor with an
outflow that is aligned with it.
