Physical Conditions in Low Ionization Regions of the Orion Nebula

J. A. Baldwin; A. Crotts; R. J. Dufour; G. J. Ferland; S. Heathcote; J. J. Hester; K. T. Korista; P. G. Martin; C. R. O'Dell; R. H. Rubin; A. G. G. M. Tielens; D. A. Verner; E. M. Verner; D. K. Walter; Z. Wen

doi:10.1086/310245

arXiv · astro-ph/9607045

Physical Conditions in Low Ionization Regions of the Orion Nebula

J. A. Baldwin·A. Crotts·R. J. Dufour·G. J. Ferland·S. Heathcote·J. J. Hester·K. T. Korista·P. G. Martin·C. R. O'Dell·R. H. Rubin·A. G. G. M. Tielens·D. A. Verner·E. M. Verner·D. K. Walter·Z. Wen

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Abstract

We reexamine the spectroscopic underpinnings of recent suggestions that [O I] and [Fe II] lines from the Orion H II region are produced in gas where the iron-carrying grains have been destroyed and the electron density is surprisingly high. Our new observations show that previous detections of [O I] 5577 were dominated by telluric emission. Our limits are consistent with a moderate density (10^4 cm^{-3}) photoionized gas. We show that a previously proposed model of the Orion H II region reproduces the observed [O I] and [Fe II] spectrum. These lines are fully consistent with formation in a dusty region of moderate density.

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J. A. Baldwin, A. Crotts, R. J. Dufour, G. J. Ferland, S. Heathcote, J. J. Hester, K. T. Korista, P. G. Martin, C. R. O'Dell, R. H. Rubin, A. G. G. M. Tielens, D. A. Verner, E. M. Verner, D. K. Walter, Z. Wen. 1996-07-08. Physical Conditions in Low Ionization Regions of the Orion Nebula. https://doi.org/10.1086/310245

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