PPAK integral field spectroscopy survey of the Orion nebula



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Sánchez, S. F. and Cardiel López, Nicolás and Verheijen, M. A. W. and Martín Gordón, D. and Vilchez, J. M. and Alves, J. (2007) PPAK integral field spectroscopy survey of the Orion nebula. Astronomy & Astrophysics, 465 (1). pp. 207-217. ISSN 0004-6361

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Official URL: http://dx.doi.org/10.1051/0004-6361:20066620


We present a low-resolution spectroscopic survey of the Orion nebula. The data are released for public use. We show the possible applications of this dataset analyzing some of the main properties of the nebula. Methods. We perform an integral field spectroscopy mosaic of an area of similar to 5' x 6' centered on the Trapezium region of the nebula, including the ionization front to the south-east. Analysis of the line fluxes and line ratios of both the individual and integrated spectra allowed us to determine the main characteristics of the ionization throughtout the nebula. Results. The final dataset comprises 8182 individual spectra, sampled in a circular area of similar to 2.7" diameter. The data can be downloaded as a single row-stacked spectra fit file plus a position table or as an interpolated datacube with a final sampling of 1.5"/pixel. The integrated spectrum across the field-of-view was used to obtain the main integrated properties of the nebula, including the electron density and temperature, the dust extinction, the Ha integrated flux (after correcting for dust reddening), and the main diagnostic line ratios. The individual spectra were used to obtain line intensity maps of the different detected lines. These maps were used to study the distribution of the ionized hydrogen, the dust extinction, the electron density and temperature, and the helium and oxygen abundance. All of them show a considerable degree of structure as already shown in previous studies. In particular, there is a tight relation between the helium and oxygen abundances and the ionization structure that cannot be explained by case B recombination theory. Simple arguments like partial ionization and dust mixed with the emitting gas may explain these relations. However a more detailed modeling is required, for which we provide the dataset.

Item Type:Article
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© ESO 2007. We thank the Spanish Plan Nacional de Astronomía program AYA2005-09413-C02-02, of the Spanish Ministery of Education and Science and the Plan Andaluz de Investigación of Junta de Andalucía as research group FQM322. M.V. thanks Matthias Steinmetz and the instrumentation group at the AIP for facilitating the construction of the PPak module and its integration into PMAS, the spectrograph used for this survey. We thank the referee, Prof. Dr. O’Dell, who helped us to improve the quality of this article with his valuable comments and suggestions, and his detailed check of the flux calibration.

Uncontrolled Keywords:H-II regions; Potsdam multiaperture spectrophotometer; Emission-line spectra; Helium abundance; Chemical-composition; Physical conditions; Echelle spectrophotometry; Intensities; Extinction
Subjects:Sciences > Physics > Astrophysics
Sciences > Physics > Astronomy
Sciences > Physics > Atmospheric physics
ID Code:28270
Deposited On:11 Feb 2015 15:52
Last Modified:10 Dec 2018 15:05

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