• 천문학회보
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• 제35권1호
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• pp.61.2-61.2
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• 2010

GMTNIRS (the GMT Near Infrared Spectrograph) is one of the first generation instrument candidates for GMT (Giant Magellan Telescope). Conceptual design studies for nine instruments were proposed last year, and the GMT organization selected 6 instruments including GMTNIRS for the next phase. GMTNIRS will be developed by an international collaboration between KASI and UT(University of Texas). KASI and UT have been also developing IGRINS (the Immersion Grating Infrared Spectrometer) which is a fore-runner instrument of GMTNIRS since 2009. In this talk, we will present the instrument details and development plan, and discuss the science case for GMTNIRS.

• 천문학회보
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• 제36권2호
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• pp.150.2-150.2
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• 2011

Volume Phase Holographic (VPH) gratings are getting more popular as dispersion elements in spectrographs. High efficiency, compact configuration, and easy handling are driving many visual spectrographs to use VPH gratings for their main dispersers or for their cross-dispersers in higher resolution spectrographs. More recently, VPH gratings are being adopted in near-infrared by some spectrographs and by a number of next generation instrument projects. IGRINS (Immersion Grating Infrared Spectrograph) uses a VPH grating as a cross-disperser in each H or K band arm. J or H band performance of VPH gratings has been proven by other instruments. But K-band VPH gratings are new to the field. In this presentation, we are going to present test results we have got so far for verification of H-band VPH gratings and development of K-band VPH gratings.

• Journal of Astronomy and Space Sciences
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• 제30권4호
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• pp.307-314
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• 2013

Infrared optical systems are operated at low temperature and vacuum (LT-V) condition, whereas the assembly and alignment are performed at room temperature and non-vacuum (RT-NV) condition. The differences in temperature and pressure between assembly/alignment environments and operation environment change the physical characteristics of optical and opto-mechanical parts (e.g., thickness, height, length, curvature, and refractive index), and the resultant optical performance changes accordingly. In this study, using input relay optics (IO), among the components of the Immersion GRating INfrared Spectrograph (IGRINS) which is an infrared spectrograph, a simulation based on the physical information of this optical system and an actual experiment were performed; and optical performances in the RT-NV, RT-V, and LT-V environments were predicted with an accuracy of $0.014{\pm}0.007{\lambda}$ rms WFE, by developing an adaptive fitting line. The developed adaptive fitting line can quantitatively control assembly and alignment processes below ${\lambda}/70$ rms WFE. Therefore, it is expected that the subsequent processes of assembly, alignment, and performance analysis could not be repeated.

• 천문학회보
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• 제44권2호
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• pp.50.2-50.2
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• 2019

We present the results of high-resolution (R ≥ 30,000) optical and near-infrared spectroscopic monitoring observations of a FU Orionis-type object, 2MASS J06593158-0405277. We have monitored 2MASS J06593158-0405277 with the Bohyunsan Optical Echelle Spectrograph (BOES) and the Immersion GRating INfrared Spectrograph (IGRINS) since December 2014. Various features produced by wind, disk, and outflow/jet were detected. The wind features varied over time and disappeared about a year after the outburst occurred. The double-peaked line profiles were detected in the optical and near-infrared, and the line widths decrease with increasing wavelength. The disk features in the optical spectra are fit well with G2-type or G5-type stellar spectra convolved with a disk rotational profile of about 45 km s^-1, which corresponds to a disk radius of about 71 R_⊙for a central mass of 0.75 M_⊙. Disk features in near-infrared spectra are fit well with a K1-type stellar spectrum convolved with a disk rotational profile of about 35 km s^-1, which corresponds to a disk radius of about 117 R_⊙ for a central mass of 0.75 M_⊙. We also detected [S II] and H2 emission lines, which are rarely found in FUors but are usually found in the earlier stage of young stellar objects. Therefore, we suggest that 2MASS J06593158-0405277 is in the relatively earlier part of Class II stage.