An Early Look at the Performance of IGRINS-2 at Gemini-North with Application to the ultrahot Jupiter, WASP-33 b
Yeon-Ho Choi, Ueejeong Jeong, Jae-Joon Lee, Hyun-Jeong Kim, Heeyoung Oh, Chan Park, Changwoo Kye, Luke Finnerty, Micheal R. Line, Krishna Kanumalla, Jorge A. Sanchez, Peter C. B. Smith, Sanghyuk Kim, Hye-In Lee, Woojin Park, Youngsam Yu, Yunjong Kim, Moo-Young Chun, Jae Sok Oh, Sungho Lee, Jeong-Gyun Jang, Bi-Ho Jang, Hyeon Cheol Seong, Cynthia B. Brooks, Gregory N. Mace, Hanshin Lee, John M. Good, Daniel T. Jaffe, Kang-Min Kim, In-Soo Yuk, Narae Hwang, Byeong-Gon Park, Hwihyun Kim, 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, Hyewon Suh, Jen Miller, Siyi Xu, Emanuele Paolo Farina, Charlie Figura, Teo Mocnik, Zachary Hartman, Mark Rawlings, Andrew Stephens, Bryan Miller, Kathleen Labrie, Paul Hirst, Byeong-Cheol Lee
Published: 2025/3/17
Abstract
Ground-based high-resolution spectroscopy enables precise molecular detections and velocity-resolved atmospheric dynamics, offering a distinct advantage over low-resolution methods for exoplanetary atmospheric studies. IGRINS-2, the successor to IGRINS, features improved throughput and enhanced sensitivity to carbon monoxide by shifting its $\textit{K}$-band coverage by 36 nm to longer wavelengths. IGRINS is a near-infrared high-resolution spectrograph mounted at McDonald, Lowell, and Gemini-South observatories. Our order-drop test shows this added range improves the CO cross-correlation signal-to-noise ratio (SNR) by 2$-$3%, confirming a measurable but modest sensitivity gain. To evaluate its performance, we attempt to investigate the atmospheric characteristics of WASP-33 b. Observations were conducted on 2024 January 7 for a total of 2.43 hours; This includes 1.46 hours in the pre-eclipse phase to capture the planet's thermal emission spectrum. We successfully detect clear cross-correlation signals from molecular species in the dayside atmosphere of WASP-33 b with a combined SNR of 7.4. More specifically, we capture CO, H$_{2}$O, and OH with SNRs of 6.3, 4.7, and 4.2, respectively. These results are consistent with previous studies and demonstrate that IGRINS-2 is well-suited for detailed investigation of exoplanetary atmospheres. We anticipate that future observations with IGRINS-2 will further advance our understanding of exoplanetary atmospheres.