PHYSICAL CONDITIONS IN LOW-IONIZATION REGIONS OF THE ORION NEBULA

We reexamine the spectroscopic underpinnings of recent suggestions tha t [O I] and [Fe II] lines from the Orion H II region are produced in g as 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 lim its are consistent with a moderate density (approximate to 10(4) cm(-3 )) photoionized gas. We show that a previously proposed model of the O rion H II region reproduces the observed [O I] and [Fe II] spectrum. T hese lines are fully consistent with formation in a dusty region of mo derate density.