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Keywords

ISM: ABUNDANCES
ISM: \ION{H}{2} REGIONS
ISM: INDIVIDUAL: ORION NEBULA

How to Cite

Temperature Variations and N+/O+ in the Orion Nebula II. The Collision Strengths. (2001). Revista Mexicana De Astrofísica Y Astronomía Serie De Conferencias, 10(1), 23-26. https://astronomia.unam.mx/journals/rmxac/article/view/2001rmxac..10...23r
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Abstract

We continue an investigation of electron temperature (T[e]), mean-square T[e] variation (t2), and the N+/O+ abundance ratio. Our previous analysis of HST spectra of the Orion Nebula used collision strengths for N+ by Stafford et al. (1994). Here we examine the consequences of changing just these collision strengths by using those of Lennon & Burke (1994). Rather than utilize the standard analytical, low electron density (N[e]) regime treatment for the analysis, we develop a numerical technique that is valid at any density. With Stafford et al. collision strengths, we find the average N[e] for the (N+, O+)-zone is 7500 cm-3, the average T[e] is 9160 K, t2 is 0.045, and N+/O+ is 0.14. Using Lennon & Burke values, the ``best" solution is found when these respective quantities are: 9000 cm-3, 9920 K, 0.00073, and 0.15. The value for t2 is dramatically lower than that found using Stafford et al. data.