Near-Infrared Spectroscopy with IGRINS-2 for Studying Multiple Stellar Populations in Globular Clusters

• Published in: Journal of the Korean Astronomical Society, 58(1) pp. 81 - 92
• Main Authors: 임동욱, 이영욱, 윤솔, 이영선, 천상현, 오희영, 이재준, 박찬, 김상혁, 정의정, 이혜인, 박우진, 유영삼, 김윤종, 천무영, 오재석, 이성호, 장정균, 장비호, 성현철, 김현정, Cynthia B. Brooks, Gregory N. Mace, 이한신, John M. Good, Daniel T. Jaffe, 김강민, 육인수, 황나래, 박병곤, 김휘현, Brian Chinn, Francisco Ramos, Pablo Prado, Ruben Diaz, John White, Eduardo Tapia, Andres Olivares, Valentina Oyarzun, Emma Kurz, Hawi Stecher, Carlos Quiroz, Ignacio Arriagada, Thomas L. Hayward, 서혜원, Jen Miller, Siyi Xu, Emanuele Paolo Farina, Charlie Figura, Teo Mocnik, Zachary Hartman, Mark Rawlings, Andrew Stephens, Bryan Miller, Kathleen Labrie, Paul Hirst
• Format: Journal Article
• Language: English
• Published: 한국천문학회 01.01.2025
• Subjects: 천문학
• ISSN: 1225-4614; 2288-890X
• DOI: 10.5303/JKAS.2025.58.1.81

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. KCI Citation Count: 0