Identification of Absorption Lines of Heavy Metals in the Wavelength Range 0.97--1.32 Micron

Abstract

Stellar absorption lines of heavy elements can give us various insights into the chemical evolution of the Galaxy and nearby galaxies. Recently developed spectrographs for the near-infrared wavelengths are becoming more and more powerful for 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 the elements heavier than the iron group, i.e., those heavier than Ni, in the Y (9760--11100 AA) and J (11600--13200 AA) bands. We considered the lines in three catalogs, i.e., Vienna Atomic Line Database (VALD), the compilation by R. Kurucz, and the list published in 1999 by Melendez and Barbuy. Candidate lines were selected based on synthetic spectra and the confirmation was done by using WINERED spectra of 13 supergiants and giants 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 the 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.

19 pages plus 18 pages with additional plots, 5 figures, 3 tables, to be published in the Astrophysical Journal Supplement Series

References in corpus (18)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• A kilonova as the electromagnetic counterpart to a gravitational-wave source
• The Dawes Review 2: Nucleosynthesis and stellar yields of low and intermediate-mass single stars
• Kilonova from post-merger ejecta as an optical and near-infrared counterpart of GW170817
• Precise radial velocities of giant stars. III. Spectroscopic stellar parameters
• Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program II: Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd and Eu
• The intermediate neutron-capture process and carbon-enhanced metal-poor stars
• On the fine structure of the Cepheid metallicity gradient in the Galactic thin disk
• An intuitive 3D map of the Galactic warp's precession traced by classical Cepheids
• Enhanced production of barium in low-mass stars: evidence from open clusters
• Carbon abundance and the N/C ratio in atmospheres of A-, F- and G-type supergiants and bright giants
• Discovery of Resolved Magnetically Split Lines in SDSS/APOGEE Spectra of 157 Ap/Bp Stars
• Into the Darkness: Classical and Type II Cepheids in the Zona Galactica Incognita
• Study of isotopic fractions and abundances of the neutron-capture elements in HD 175305
• Method to Estimate the Effective Temperatures of Late-Type Giants using Line-Depth Ratios in the Wavelength Range 0.97-1.32$\mu$m
• FeI lines in 0.91-1.33 $\mu$m spectra of red giants for measuring the microturbulence and metallicities
• Chemical Abundances Of Open Clusters From High-Resolution Infrared Spectra. I. NGC 6940
• Galactic r-process abundance feature shaped by radial migration

Cited by in corpus (8)

• Effective temperatures of red supergiants estimated from line-depth ratios of iron lines in the YJ bands, 0.97--1.32 micron
• The Galactic Distribution of Phosphorus: A Survey of 163 Disk and Halo Stars
• Stellar population astrophysics (SPA) with the TNG -- The Arcturus Lab
• Absorption Lines in the 0.91-1.33 $\mu$m Spectra of Red Giants for Measuring Abundances of Mg, Si, Ca, Ti, Cr, and Ni
• Line-depth ratios as indicators of effective temperature and surface gravity
• The effect of surface gravity on line-depth ratios in the wavelength range 0.97-1.32 μm
• MAGIS (Measuring Abundances of red super Giants with Infrared Spectroscopy) project I. Establishment of an abundance analysis procedure for red supergiants and its evaluation with nearby stars
• Gaia FGK Benchmark Stars: Selecting Infrared Lines for Abundance Determination