SILICON ABUNDANCES IN NEARBY STARS FROM THE Si I INFRARED LINES

Journal Article · Fri Aug 10 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/755/1/36· OSTI ID:22039163

Shi, J R; Tan, K F; Zhao, G ^[1]; Takada-Hidai, M ^[2]; Takeda, Y ^[3]; Hu, S M; Cao, C ^[4]

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1. Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)
2. Liberal Arts Education Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan)
3. National Astronomical Observatory of Japan 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
4. Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Shandong University at Weihai 264209 (China)

We have used high-resolution, high signal-to-noise ratio infrared spectra from the Subaru Telescope atop Mauna Kea. Line formation calculations of Si I infrared lines in the atmospheres of nearby stars are presented. All abundance results of [Si/Fe] are derived from local thermodynamic equilibrium (LTE) and NLTE statistical equilibrium calculations and spectrum synthesis methods. We found that NLTE effects for Si I infrared lines are important even for metal-rich stars (>0.1 dex), and the NLTE effects may depend on the surface gravities. A good agreement of silicon abundances between the optical and infrared lines is obtained when the NLTE effects are included, while a large difference is found for the LTE results. The derived silicon abundances are overabundant for metal-poor stars.

• OSTI ID: 22039163
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 755; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
ELEMENT ABUNDANCE
GALACTIC EVOLUTION
GALAXIES
GRAVITATION
INFRARED SPECTRA
LTE
METALS
RESOLUTION
SIGNAL-TO-NOISE RATIO
SILICON
STARS
STELLAR ATMOSPHERES