Calibrating nebular diagnostics of T_* and abundance
| dc.creator | Oey, M. S. | |
| dc.creator | Shields, J. C. | |
| dc.creator | Dopita, M. A. | |
| dc.creator | Smith, R. C. | |
| dc.date | 2001-01-16 | |
| dc.date.accessioned | 2026-07-07T01:57:25Z | |
| dc.date.available | 2026-07-07T01:57:25Z | |
| dc.description | We obtained nebular spectroscopy of LMC HII regions having classified stellar populations, thereby strongly constraining the ionization input parameters. Using photoionization models, we then evaluate the performance of nebular diagnostics of T_* and abundance. We introduce [Ne III]/H-beta as a nebular diagnostic of the ionizing stellar T_*. In contrast to the widely-used η-prime parameter, [Ne III]/H-beta has greater sensitivity to mid and early O-stars, and is robust to nebular morphology and the presence of shocks. We present a preliminary calibration of both T_* diagnostics for LMC metallicity. We also introduce S234 = ([S II] + [S III] + [S IV])/H-beta as a diagnostic of S abundance. S234 is much less sensitive to the nebular ionization parameter than is S23 or R23. The intensity of [S IV]10.5 microns is easily estimated from the optical and near-IR line ratios. We present calibrations of S23 and S234 that are reliable at metallicities Z < 0.5 Z_sol. | |
| dc.description | 6 pages, 3 figures, uses rmaa.cls (included); invited contribution to "Ionized Gaseous Nebulae", Rev.Mex.A.A., Ser.Conf | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0101273 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0101273 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/2376 | |
| dc.subject | Astrophysics | |
| dc.title | Calibrating nebular diagnostics of T_* and abundance | |
| dc.type | text |