Near-Infrared Spectroscopy with IGRINS-2 for Studying Multiple Stellar Populations in Globular Clusters
Abstract
Recent advancements in near-infrared (NIR) spectroscopy have opened new opportunities for studying multiple stellar populations in globular clusters (GCs), particularly for newly discovered clusters in the inner Milky Way. While optical spectroscopy has traditionally played a primary role in detailed chemical abundance studies of GCs, the increasing discovery of GCs in highly reddened environments underscores the need for robust NIR spectroscopic methods. To evaluate the utility of high-resolution NIR spectroscopy for studying multiple stellar populations, we observed six stars in M5, a well-studied halo GC, using the recently commissioned IGRINS-2 spectrograph on the Gemini-North telescope. Our chemical abundance measurements in the NIR wavelength range show good agreement with those derived from high-resolution optical spectroscopy, with minor systematic offsets in elements such as Na and Mg. In addition, the measured chemical abundance ratios clearly reproduce the distinctive patterns of multiple stellar populations, including the Na-O anti-correlation. The ability of NIR spectroscopy to measure C, N, and O abundances with high precision further enhances its utility for studying chemical properties of stars and GCs. Our findings demonstrate that IGRINS-2 and similar instruments have significant potential to advance our understanding of GC formation, stellar chemical evolution, and the evolutionary history of the Milky Way.
Keywords
Cite
@article{arxiv.2504.03017,
title = {Near-Infrared Spectroscopy with IGRINS-2 for Studying Multiple Stellar Populations in Globular Clusters},
author = {Dongwook Lim and Young-Wook Lee and Sol Yun and Young Sun Lee and Sang-Hyun Chun and Heeyoung Oh and Jae-Joon Lee and Chan Park and Sanghyuk Kim and Ueejeong Jeong and Hye-In Lee and Woojin Park and Youngsam Yu and Yunjong Kim and Moo-Young Chun and Jae Sok Oh and Sungho Lee and Jeong-Gyun Jang and Bi-Ho Jang and Hyeon Cheol Seong and Hyun-Jeong Kim and Cynthia B. Brooks and Gregory N. Mace and Hanshin Lee and John M. Good and Daniel T. Jaffe and Kang-Min Kim and In-Soo Yuk and Narae Hwang and Byeong-Gon Park and Hwihyun Kim and Brian Chinn and Francisco Ramos and Pablo Prado and Ruben Diaz and John White and Eduardo Tapia and Andres Olivares and Valentina Oyarzun and Emma Kurz and Hawi Stecher and Carlos Quiroz and Ignacio Arriagada and Thomas L. Hayward and Hyewon Suh and Jen Miller and Siyi Xu and Emanuele Paolo Farina and Charlie Figura and Teo Mocnik and Zachary Hartman and Mark Rawlings and Andrew Stephens and Bryan Miller and Kathleen Labrie and Paul Hirst},
journal= {arXiv preprint arXiv:2504.03017},
year = {2025}
}
Comments
12 pages, 7 figures, accepted for publication in JKAS