Bibcode
DOI
Gonzalez-Delgado, Rosa M.; Perez, E.; Tenorio-Tagle, G.; Vilchez, J. M.; Terlevich, Elena; Terlevich, Roberto; Telles, Eduardo; Rodriguez-Espinosa, J. M.; Mas-Hesse, Miguel; Garcia-Vargas, Maria Luisa; Diaz, Angeles I.; Cepa, J.; Castaneda, H.
Bibliographical reference
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 437, no. 1, p. 239-261
Advertised on:
12
1994
Journal
Citations
167
Refereed citations
145
Description
We present narrowband H-alpha imaging and long-slit optical and
near-infrared spectroscopy of the giant H II region NGC 2363. The
spectroscopic data are taken at two positions, in the brightest core and
in a knot approximately 6 sec to the east, where we have found broad
emission lines at 4660 A and 5810 A attributed to WC stars which suggest
an age for the region between 3 and 5 Myr. The observations also confirm
previously reported low-intensity broad components in H-alpha and (O
III) emission lines, which extend some 500 pc across the region. For 15
different zones within the nebula, we derive the physical conditions and
the chemical abundance of oxygen, nitrogen, neon, sulfur, and helium. No
significant spatial variations are found for these abundances, with a
mean value of oxygen 12 + log(O/H) = 7.89 and a helium mass fraction of
y = 0.24. electron temperatures deduced from the Paschen discontinuity
have been obtained for two different regions. These Paschen temperatures
are significantly smaller than those obtained from the collisionally
excited emission line diagnostics, suggesting the presence of large
temperature fluctuations. The effect of these temperature fluctuations
in the determination of the chemical abundances has been estimated.