Anomalous Fe II Spectral Effects and High H I Lyα Temperature in Gas Blobs Near η Carinae

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Bibtex

@article{d52b9e6274df4922a8ceece7858030e7,
title = "Anomalous Fe II Spectral Effects and High H I Lyα Temperature in Gas Blobs Near η Carinae",
abstract = "We consider the origin of the anomalously high intensity of theultraviolet Fe II lambda 2507/2509 A lines observed with high spatialand spectral resolutions from gas blobs (GBs) near Carinae. This rareeffect in stellar spectra is attributable to a combination of severalfactors: (1) the high hydrogen density (>10^{8} cm^{-3}) that ensuresthe blocking of the Lyman continuum by GBs and, accordingly, theformation of a cold H I region with completely ionized Fe atoms; (2) thesmall distance between the GBs and the central star that ensures a high(>8000-10 000 K) Ly_alpha H spectral temperature, which photoexcitesFe II selectively; and (3) the population of Fe II levels and,accordingly, the opening of a stimulated emission channel, whichtogether with spontaneous transitions creates a radiative cycle where asingle Fe II ion can multiply absorb Ly_alpha emission.",
author = "Sveneric Johansson and Vladilen Letokhov",
year = "2004",
doi = "10.1134/1.1647477",
language = "English",
volume = "30",
pages = "58--63",
journal = "Astronomy Letters",
issn = "1063-7737",
publisher = "MAIK Nauka/Interperiodica",
number = "1",

}