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

Sveneric Johansson; Vladilen Letokhov

doi:10.1134/1.1647477

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

Sveneric Johansson, Vladilen Letokhov

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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.

Original language	English
Pages (from-to)	58-63
Journal	Astronomy Letters
Volume	30
Issue number	1
DOIs	https://doi.org/10.1134/1.1647477
Publication status	Published - 2004

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Astronomy, Astrophysics and Cosmology

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10.1134/1.1647477

Johansson_MAIK2004

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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 = "Pleiades Publishing",

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TY - JOUR

T1 - Anomalous Fe II Spectral Effects and High H I Lyα Temperature in Gas Blobs Near η Carinae

AU - Johansson, Sveneric

AU - Letokhov, Vladilen

PY - 2004

Y1 - 2004

N2 - 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.

AB - 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.

U2 - 10.1134/1.1647477

DO - 10.1134/1.1647477

M3 - Article

SN - 1063-7737

VL - 30

SP - 58

EP - 63

JO - Astronomy Letters

JF - Astronomy Letters

IS - 1

ER -

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

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