Photoionized Herbig-Haro objects in the Orion Nebula through deep high-spectral resolution spectroscopy - III. HH 514

Méndez-Delgado, J. E.; Esteban, C.; García-Rojas, J.; Henney, W. J.
Bibliographical reference

Monthly Notices of the Royal Astronomical Society

Advertised on:
Number of authors
IAC number of authors
Refereed citations
We analyse the physical conditions and chemical composition of the photoionized Herbig-Haro object HH 514, which emerges from the protoplanetary disc (proplyd) 170-337 in the core of the Orion Nebula. We use high-spectral resolution spectroscopy from Ultraviolet and Visual Echelle Spectrograph 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 $n_{\rm e}= (2.3 \pm 0.1) \times 10^5 \rm{cm}^{-3}$ and $n_{\rm e}= (7 \pm 1) \times 10^4 \rm{ cm}^{-3}$, respectively, both with Te ≍ 9000 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 are 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 disc 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 proplyds, which filter large sulfide dust grains during the accretion of matter from the disc to the central star. We also show that published kinematics of molecular emission close to the central star are not consistent with either a disc perpendicular to the optical jet, or with an outflow that is aligned with it.
Related projects
Izquierda - Imagen RGB de la nebulosa de Orión y M43 obtenida filtros estrechos con la cámara WFC en el INT: H alfa (rojo), [S II] 6716+30 (verde), [O III] 5007 (azul). Derecha - Imagen en falso color de la nebulosa planetaria NGC 6778. En azul se ve la emisión en la línea de O II tomada con el filtro sintonizable azul del instrumento OSIRIS en el GTC; en verde imagen con el filtro estrecho de [O III] del Nordic Optical Telescope (NOT).
Physics of Ionized Nebulae

The research that is being carried out by the group can be condensed into two main lines: 1) Study of the structure, dynamics, physical conditions and chemical evolution of Galactic and extragalactic ionized nebulae through detailed analysis and modelization of their spectra. Investigation of chemical composition gradients along the disk of our

García Rojas