FeI lines in 0.91-1.33 $\mu$m spectra of red giants for measuring the microturbulence and metallicities

Abstract

For a detailed analysis of stellar chemical abundances, high-resolution spectra in the optical have mainly been used, while the development of near-infrared (NIR) spectrograph has opened new wavelength windows. Red giants have a large number of resolved absorption lines in both the optical and NIR wavelengths, but the characteristics of the lines in different wave passbands are not necessarily the same. We present a selection of FeI lines in the $z^{\prime }$, $Y$, and $J$ bands (0.91-1.33 $\mu$m). On the basis of two different lists of lines in this range, the Vienna Atomic Line Database (VALD) and the catalog published by Meléndez & Barbuy in 1999 (MB99), we selected sufficiently strong lines that are not severely blended and compiled lists with 107 FeI lines in total (97 and 75 lines from VALD and MB99, respectively). Combining our lists with high-resolution ($\lambda /\Delta \lambda =28,000$) and high signal-to-noise ($>500$) spectra taken with a NIR spectrograph, WINERED, we present measurements of the iron abundances of two prototype red giants: Arcturus and $\mu$ Leo. A bootstrap method for determining the microturbulence and abundance together with their errors is demonstrated. The standard deviations of $\log {\epsilon }_{\mathrm{Fe}}$ values from individual FeI lines are significantly smaller when we use the lines from MB99 instead of those from VALD. With the MB99 list, we obtained $\xi =1.20\pm 0.11\mathrm{km}{\mathrm{s}}^{-1}$ and $\log {\epsilon }_{\mathrm{Fe}}=7.01\pm 0.05$ dex for Arcturus, and $\xi =1.54\pm 0.17\mathrm{km}{\mathrm{s}}^{-1}$ and $\log {\epsilon }_{\mathrm{Fe}}=7.73\pm 0.07$ dex for $\mu$ Leo. These final values show better agreements with previous values in the literature than the corresponding values we obtained with VALD.

14 pages, 8 figures, 5 tables, accepted for publication in ApJ

References in corpus (8)

• Precise radial velocities of giant stars. III. Spectroscopic stellar parameters
• Oxygen, Sodium, Magnesium and Aluminium as tracers of the Galactic Bulge Formation
• Chemical similarities between Galactic bulge and local thick disk red giant stars
• Oxygen Abundances in Nearby Stars. Clues to the formation and evolution of the Galactic disk
• Chemical Evolution of the Galactic Bulge as Derived from High-Resolution Infrared Spectroscopy of K and M Red Giants
• Identifying Contributions to the Stellar Halo from Accreted, Kicked-Out, and In Situ Populations
• Abundances in bulge stars from high-resolution, near-IR spectra I. The CNO elements observed during the science verification of CRIRES at VLT
• Method to Estimate the Effective Temperatures of Late-Type Giants using Line-Depth Ratios in the Wavelength Range 0.97-1.32$\mu$m

Cited by in corpus (11)

• The chemical composition of globular clusters in the Local Group
• 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
• Identification of Absorption Lines of Heavy Metals in the Wavelength Range 0.97--1.32 Micron
• 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
• 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
• Stellar population astrophysics (SPA) with the TNG: Measurement of the He I 10830Å line in the open cluster Stock 2
• Kinematical and dynamical properties of recently discovered bulge and disc star clusters with WINERED
• Gaia FGK Benchmark Stars: Selecting Infrared Lines for Abundance Determination