Wide binaries, with separations between two stars from a few AU to more than
several thousand AU, are valuable objects for various research topics in
Galactic astronomy. As the number of newly reported wide binaries continues to
increase, studying the chemical abundances of their component stars becomes
more important. We conducted high-resolution near-infrared (NIR) spectroscopy
for six pairs of wide binary candidates using the Immersion Grating Infrared
Spectrometer (IGRINS) at the Gemini-South telescope. One pair was excluded from
the wide binary samples due to a significant difference in radial velocity
between its component stars, while the remaining five pairs exhibited
homogeneous properties in 3D motion and chemical composition among the pair
stars. The differences in [Fe/H] ranged from 0.00 to 0.07 dex for these wide
binary pairs. The abundance differences between components are comparable to
the previous results from optical spectroscopy for other samples. In addition,
when combining our data with literature data, it appears that the variation of
abundance differences increases in wide binaries with larger separations.
However, the SVO2324 and SVO3206 showed minimal differences in most elements
despite their large separation, supporting the concept of multiple formation
mechanisms depending on each wide binary. This study is the first approach to
the chemical properties of wide binaries based on NIR spectroscopy. Our results
further highlight that NIR spectroscopy is an effective tool for stellar
chemical studies based on equivalent measurements of chemical abundances from
the two stars in each wide binary system.Comment: 16 pages, 9 figures, accepted for publication in A