• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.76-76
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• 2011

The SPICA (SPace Infrared Telescope for Cosmology & Astrophysics) project is a next-generation astronomical mission optimized for mid- and far-infrared observation with a cryogenically cooled 3m-class telescope. Due to its high angular resolution and unprecedented sensitivity, SPICA will enable us to resolve many key issues from the star-formation history of the universe to the planetary formation. As an international collaboration, KASI proposed the near-infrared instrument which is composed of two parts; (1) science observation with the capability of imaging and spectroscopy covering $0.7{\mu}m$ to $5{\mu}m$ (FPC-S) (2) fine guiding to stabilize and improve the attitude (FPC-G). Here, we present the current status of SPICA/FPC.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.73.2-73.2
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• 2013

An autoguiding system for astronomical observations should be accurate and stable for efficient data taking. IGRINS (Immersion Grating Infrared Spectrograph) is a high resolution near-IR spectrograph which is now developed by Korea Astronomy and Space Science Institute and the University of Texas. We plan to attach this instrument on the 2.7m telescope at the McDonald observatory in 2013. IGRINS consists on three detector modules, i. e., H and K band spectrograph modules and a K band slit camera module. We use the slit camera for autoguiding of the telescope. In this poster, we describe the system architecture of the hardware and software of the autoguiding system, and the algorithm which would effectively find centers of stellar images on or outside of the slit of the infrared array.

• Publications of The Korean Astronomical Society
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• v.22 no.4
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• pp.201-209
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• 2007

We have preliminarily designed two infrared optical systems of the multi-purpose infrared camera system (MIRIS) which is the main payload of STSAT-3. Each optical system consists of a Cassegrain telescope, a field lens and a 1:1 re-imaging lens system that is essential for providing a cold stop. The Cassegrain telescope is identical for both of two infrared cameras, but the field correction lens and re-imaging lens system are different from each other because of different bands of wavelength. The effective aperture size is 100mm in diameter and the focal ratio is f/5. The total length of the optical system is 300mm and the position of the cold stop is 25mm from the detector focal plane. The RMS spot size is smaller than $40{\mu}m$ over the whole detector plane.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.38.3-38.3
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• 2021

We are developing an optomechanical design of infrared telescope for the CubeSat and Unmanned Aerial Vehicle (UAV) which adapts the Linear Astigmatism Free- Three Mirror System in the confocal off-axis condition. The small entrance pupil (diameter of 40 mm) and the fast telescope (f-number of 1.9) can survey large areas. The telescope structure consists of three mirror modules and a sensor module, which are assembled on the base frame. The mirror structure has duplex layers to minimize a surface deformation and physical size of a mirror mount. All the optomechanical parts and three freeform mirrors are made from the same material, i.e., aluminum 6061-T6. The Coefficient of Thermal Expansion matching single material structure makes the imaging performance to be independent of the thermal expansion. We investigated structural characteristics against external loads through Finite Element Analysis. We confirmed the mirror surface distortion by the gravity and screw tightening, and the overall contraction/expansion following the external temperature environment change (from -30℃ to +30℃).

• Journal of The Korean Astronomical Society
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• v.31 no.2
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• pp.127-140
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• 1998

With a large format near-infrared camera at the 2.2-m telescope on Mauna Kea Observatory, we performed J K near-infrared observations for the metal rich globular cluster NGC6712. This cluster lies near the galactic plane and therefore suffers heavy reddening. We present the near-infrared color-magnitude diagram and also derive the metallicity ([Fe/H] ${\~}-0.96{\pm}0.27$) as well as its distance modulus ((m - M) ${\~}13.42{\pm}0.12$).

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.41.1-41.1
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• 2010

IGRINS (the Immersion GRating Infrared Spectrograph) is a high resolution infrared spectrograph which is being developed by a collaboration of the University of Texas, the Korea Astronomy and Space Science Institute, and Kyung Hee University. The wavelength calibration unit of IGRINS will be situated between the telescope flange and IGRINS dewar. It will include Th-Ar hallow cathode lamp, optical elements, and gas absorption cell for the case that requires precise calibration (e.g., radial velocity observation). The system will also use a tungsten halogen lamp in an integrating sphere as a blackbody source for the flat-field imaging. IGRINS will be placed initially on the McDonald 2.7m Harlan J. Smith telescope and later on 4-8m class telescopes. We present an overview of the plan for the wavelength calibration sources and of the development process for the optical and mechanical design of the IGRINS calibration system.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.251-255
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• 2017

Submillimetre and millimetre-wave surveys with Herschel and the South Pole Telescope have revolutionised the discovery of strong gravitational lenses. Their follow-ups have been greatly facilitated by the multi-wavelength supplementary data in the survey fields. The forthcoming Euclid optical/near-infrared space telescope will also detect strong gravitational lenses in large numbers, and orbital constraints are likely to require placing its deep survey at the North Ecliptic Pole (the natural deep field for a wide class of ground-based and space-based observatories including AKARI, JWST and SPICA). In this paper I review the current status of the multi-wavelength survey coverage in the NEP, and discuss the prospects for the detection of strong gravitational lenses in forthcoming or proposed facilities such as Euclid, FIRSPEX and SPICA.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.56.1-56.1
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• 2016

A low-mass star-forming region, L1251B, is an excellent example of a small and nearby group of protostellar objects. L1251B has been mapped spectroscopically with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. IRS has provided mid-IR emission lines (e.g., [Fe II], [Ne II], and ro-vibrational H2) and absorption features of CO2 and H2O ice in studying the physical state of the ionized gas and the material residing in the circumstellar environments. We will present the distribution of outflows and ice components in L1251B.

• 한국지구과학회:학술대회논문집
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• 2005.09a
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• pp.187-189
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• 2005

1990년 궤도에 진입한 허블우주망원경(이하 HST)이 수년내에 그 수명을 다하여 임무를 마치게 되면, 2007에서 2011년을 전후로 하여 미국, 일본과 유럽 연합은 각각 차세대 우주 망원경을 발사할 예정이다. 2007년 유럽연합의 Herschel, 2011년 미국의 JWST (James Webb Space Telescope), 그리고 2012년 일본의 SPICA가 차례로 발사되어 예정된 관측을 수행하게 된다. 기존의 HST가 가시광선 영역과 근자외선 영역을 주로 관측 했던 것과는 달리 이들 차세대 우주망원경들은 주로 근적외선에서 원적외선 영역까지를 관측하는 것을 주된 임무로 하고 있다. 본 연구에서는 한국천문학자들이 이들 차세대 망원경의 제작에 참여하는 부분에 대해 소개하고, 이들 망원경을 활용한 적외선 천문학, 특히 항성의 형성과 관련된 부분에 관하여 소개하고자 한다.

• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.143-149
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• 2005

KASI (Korea Astronomy and Space Science Institute) is developing the near-infrared camera system named KASINICS (KASI Near-Infrared Camera System) which will be installed at the 60cm f/13.5 Ritchey-Chretien telescope of the Sobaeksan Optical Astronomy Observatory (SOAO). The camera system is optimized for JHKL bands and has a 6 arcmin FOV. The optical system consists of two spherical mirrors and a 8-position filter wheel. With the exception for the dewar window, all optical elements are cooled inside cryogenic dewar. Since the Offner system is adopted to prevent thermal noises from outside of the telescope primary mirror, the secondary mirror of the Offner system acts as a cold Lyot stop. The optical performance does not change by temperature variations because the Aluminum mirrors contract and expand homogeneously with its mount. We finished the design and fabrication of the optical parts and are now aligning the optical system. We plan to have a test observation on 2006 January.