Identification of Absorption Lines of Heavy Metals in the Wavelength Range 0.97-1.32 μm
Abstract
Stellar absorption lines of heavy elements can give us various insights into the chemical evolution of our Galaxy and other nearby galaxies. Recently developed spectrographs for the near-infrared wavelengths are becoming more and more powerful at producing a large number of high-quality spectra, but identification and characterization of the absorption lines in the infrared range remain to be fulfilled. We searched for lines of elements heavier than the iron group, I.e., those heavier than Ni, in the Y (9760-11100 Å) and J (11600-13200 Å) bands. We considered the lines in three catalogs, I.e., the Vienna Atomic Line Database, the compilation by R. Kurucz, and the list published in 1999 by Meléndez & Barbuy. Candidate lines were selected based on synthetic spectra, and the confirmation was done by using WINERED spectra of 13 giants and supergiants within FGK spectral types (spanning 4000-7200 K in the effective temperature). We have detected lines of Zn I, Sr II, Y II, Zr I, Ba II, Sm II, Eu II, and Dy II, in the order of atomic number. Although the number of the lines is small, 23 in total, they are potentially useful diagnostic lines of the Galactic chemical evolution, especially in those regions for which interstellar extinction hampers detailed chemical analyses with spectra in shorter wavelengths. We also report the detection of lines whose presence was not predicted by the synthetic spectra created with the above three line lists.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- January 2020
- DOI:
- arXiv:
- arXiv:1911.11277
- Bibcode:
- 2020ApJS..246...10M
- Keywords:
-
- Spectroscopy;
- High resolution spectroscopy;
- Spectral line identification;
- Spectral line lists;
- Stellar spectral lines;
- Late-type giant stars;
- Late-type supergiant stars;
- Late-type dwarf stars;
- Near infrared astronomy;
- 1558;
- 2096;
- 2073;
- 2082;
- 1630;
- 908;
- 910;
- 906;
- 1093;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 19 pages plus 18 pages with additional plots, 5 figures, 3 tables, to be published in the Astrophysical Journal Supplement Series