2026-05-21 東京大学
＜関連情報＞
- https://www.s.u-tokyo.ac.jp/ja/press/11140/
- https://iopscience.iop.org/article/10.3847/1538-4365/ae5a9d
YJバンドにおける太陽類似物質の高精度近赤外線存在量測定 High-precision Near-infrared Abundances of Solar Analogs in the YJ Bands
Noriyuki Matsunaga, Takuji Tsujimoto, Daisuke Taniguchi, Hiroaki Sameshima, Shogo Otsubo, Tomomi Takeuchi, Yuki Sarugaku, Ilaria Petralia, Scarlet Elgueta, Matilde Coello-Guzmán,…
The Astrophysical Journal supplement Series Published: 2026 May 20
DOI:10.3847/1538-4365/ae5a9d
Abstract
We present a near-infrared abundance analysis of 46 solar analogs with known ages, observed with the WINERED WIDE-mode spectrograph at a resolution of λ/Δλ = 28,000. Using an empirically calibrated, line-by-line approach in the YJ bands (0.976–1.089 and 1.182–1.319 μm), we derive abundances for 16 elements. Despite the intrinsic weakness of near-infrared phosphorus diagnostics, the combination of five P i lines yields a typical uncertainty half-width of ∼0.04 dex, providing an estimate of the internal precision over the solar-analog sample. For other elements, the internal precision ranges from ∼0.01 dex for Fe and Si to over 0.05–0.14 dex for elements with only a couple of lines available. The resulting per-object abundances for various elements are consistent with previous measurements using high-precision optical spectra with residuals of 0.03–0.2 dex depending on the element. The inferred age–[X/Fe] relations reproduce known trends for the thin disk, while extending them to elements difficult to access in the optical, including P and K. We find the slope of the age–[P/Fe] relation is steeper than that for α elements, which provides an empirical constraint for future modeling of Galactic phosphorus evolution. In addition, we publish a high signal-to-noise ratio (S/N 500–1000) reference spectrum constructed by combining solar-analog spectra, together with the spectra of individual stars, and an empirically calibrated line list with per-line zero-point corrections, for future near-infrared spectroscopic studies.
