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

Johansson, Sveneric LU and Letokhov, Vladilen LU (2004) In Astronomy Letters 30(1). p.58-63
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,... (More)
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. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Astronomy Letters
volume
30
issue
1
pages
58 - 63
publisher
MAIK Nauka/Interperiodica
external identifiers
  • wos:000188764900006
  • scopus:1442355279
ISSN
1063-7737
DOI
10.1134/1.1647477
language
English
LU publication?
yes
id
d52b9e62-74df-4922-a8ce-ece7858030e7 (old id 129645)
date added to LUP
2007-07-13 12:05:21
date last changed
2017-01-01 04:46:10
@article{d52b9e62-74df-4922-a8ce-ece7858030e7,
  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       = {Johansson, Sveneric and Letokhov, Vladilen},
  issn         = {1063-7737},
  language     = {eng},
  number       = {1},
  pages        = {58--63},
  publisher    = {MAIK Nauka/Interperiodica},
  series       = {Astronomy Letters},
  title        = {Anomalous Fe II Spectral Effects and High H I Lyα Temperature in Gas Blobs Near η Carinae},
  url          = {http://dx.doi.org/10.1134/1.1647477},
  volume       = {30},
  year         = {2004},
}