Bibcode
Mesa-Delgado, A.; Núñez-Díaz, M.; Esteban, C.; López-Martín, L.; García-Rojas, J.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 417, Issue 1, pp. 420-433.
Advertised on:
10
2011
Citations
21
Refereed citations
20
Description
We present integral field spectroscopy of two selected zones in the
Orion nebula obtained with the Potsdam Multi-Aperture Spectrophotometer,
covering the optical spectral range from 3500 to 7200 Å and with a
spatial resolution of 1 arcsec. The observed zones are located on the
prominent Bright bar and on the brightest area at the north-east of the
Orion south cloud, both containing remarkable ionization fronts. We
obtain maps of emission-line fluxes and ratios, electron density and
temperatures, and chemical abundances. We study the ionization structure
and morphology of both fields, whose ionization fronts show different
inclination angles with respect to the plane of the sky. We find that
the maps of electron density, O+/H+ and O/H ratios
show a rather similar structure. We interpret this as produced by the
strong dependence on density of the [O II] lines used to derive the
O+ abundance, and that our nominal values of electron density
- derived from the [S II] line ratio - may be slightly higher than the
appropriate value for the O+ zone. We measure the faint
recombination lines of O II in the field at the north-east of the Orion
south cloud, allowing us to explore the so-called abundance discrepancy
problem. We find a rather constant abundance discrepancy across the
field and a mean value similar to that determined in other areas of the
Orion nebula, indicating that the particular physical conditions of this
ionization front do not contribute to this discrepancy. Based on
observations collected at the Centro Astronómico Hispano
Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck
Institut für Astronomie and the Instituto de Astrofísica de
Andalucía (CSIC).
Related projects
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
Jorge
García Rojas