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Full-Text Articles in Physical Sciences and Mathematics
Pumping Up The [N I] Nebular Lines, Gary J. Ferland, W. J. Henney, C. R. O'Dell, R. L. Porter, P. A. M. Vanhoof, R. J. R. Williams
Pumping Up The [N I] Nebular Lines, Gary J. Ferland, W. J. Henney, C. R. O'Dell, R. L. Porter, P. A. M. Vanhoof, R. J. R. Williams
Physics and Astronomy Faculty Publications
The optical [N I] doublet near 5200 Å is anomalously strong in a variety of emission-line objects. We compute a detailed photoionization model and use it to show that pumping by far-ultraviolet (FUV) stellar radiation previously posited as a general explanation applies to the Orion Nebula (M42) and its companion M43; but, it is unlikely to explain planetary nebulae and supernova remnants. Our models establish that the observed nearly constant equivalent width of [N I] with respect to the dust-scattered stellar continuum depends primarily on three factors: the FUV to visual-band flux ratio of the stellar population, the optical properties …
Rovibrationally Resolved Direct Photodissociation Through The Lyman And Werner Transitions Of H2 For Fuv/X-Ray-Irradiated Environments, C. D. Gay, N. P. Abel, R. L. Porter, P. C. Stancil, Gary J. Ferland, G. Shaw, P. A. M. Vanhoof, R. J. R. Williams
Rovibrationally Resolved Direct Photodissociation Through The Lyman And Werner Transitions Of H2 For Fuv/X-Ray-Irradiated Environments, C. D. Gay, N. P. Abel, R. L. Porter, P. C. Stancil, Gary J. Ferland, G. Shaw, P. A. M. Vanhoof, R. J. R. Williams
Physics and Astronomy Faculty Publications
Using ab initio potential curves and dipole transition moments, cross-section calculations were performed for the direct continuum photodissociation of H2 through the B1Σ+u ← X1Σ+g (Lyman) and C1Πu ← X1Σ+g (Werner) transitions. Partial cross-sections were obtained for wavelengths from 100 Å to the dissociation threshold between the upper electronic state and each of the 301 bound rovibrational levels v''J'' within the ground electronic state. The resulting cross-sections are incorporated into three representative classes of interstellar gas models: diffuse clouds, photon-dominated regions, and …