• The Bulletin of The Korean Astronomical Society
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• v.30 no.1
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• pp.28.2-28.2
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• 2005

• Bulletin of the Korean Chemical Society
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• v.15 no.9
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• pp.739-743
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• 1994

A spectroelectrochemical system assembled with a white light source, bifurcated optical fiber, Oriel Multispec spectrograph, and a charge-coupled device (CCD) detector is described. The system is shown to be capable of acquiring a whole spectrum in the spectral range of 290-800 nm in 25 ms or a longer period during electrochemical experiments at reflective working electrodes such as platinum or mercury. The utility of the system in studying electrochemical reactions during the potential scan, galvanostatic electrolysis, or after the potential step is demonstrated.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.59.3-59.3
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• 2018

공생별 AG Dra와 UV Aur에 대해 지난 10여년간 보현산천문대 1.8m망원경과 고분산 에셀 분광기 BOES(BOao Echelle Spectrograph)로 분광관측을 수행해 왔다. 최근 2017년 11월 - 2018년 6월 관측에서, AG Dra의 Fe II 방출선과 UV Aur $H{\alpha}$ 방출선이 예년과 다른 변화 모습을 보이고 있음을 찾아내었다. 이에 대한 변화 원인을 공전주기, 밝기 변화 또는 다른 이유와 연관지어 설명하고자 한다.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.39-40
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• 1996

Using the Keck 10 m telescope data with the HIRES spectrograph, we analyzed the evolution of Lyman$\alpha$ forest clouds at z > 2 down to the HI column density $10^{12.8}cm^{-2}$. The number density per unit column density does not change with redshifts at lower HI cloumn density ($N_{HI} < 10^{14}cm^{-2}$), while the forest clouds at higher column density disappear rapidly. The cutoff b value, the thermal temperature indicator, increases as redshift decreases. The correlation strength seems to be stronger as redshift decreases.

• Bulletin of the Korean Space Science Society
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• 2000.10a
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• pp.54-54
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• 2000

No Abstract, See Full Text

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.52.3-53
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• 2015

The GMT-Consortium Large Earth Finder (G-CLEF) is a fiber-fed, optical band high dispersion echelle spectrograph that selected as the first light instrument for the Giant Magellan Telescope (GMT). This G-CLEF has been designed to be a general- purpose echelle spectrograph with the precisional radial velocity (PRV) capability of 10 cm/sec as a goal. The preliminary design review (PDR) was held on April 8 to 10, 2015 and the scientific observations will be started in 2022 with four mirrors installed on GMT. We have been participating in this preliminary design study in flexure control camera (slit monitoring system), calibration lamp sources, dichroic assembly and the fabrication of the proto-Mangin Mirror. We present the design concept on the parts KASI undertaken, introducing the specifications and capabilities of G-CLEF.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.20.1-20.1
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• 2011

We present the results of far-ultraviolet (FUV) observations of comet C/2001 Q4 (NEAT) obtained with Far-ultraviolet Imaging Spectrograph (FIMS) on board the Korean microsatellite STSAT-1, which operated at an altitude of 700 km in a sun-synchronous orbit. FIMS is a dual-channel imaging spectrograph (S channel 900-1150 ${\AA}$, L channel 1350-1750 ${\AA}$, ${\lambda}/{\Box}{\lambda}$ ~ 550) with large image fields of view (S: $4^{\circ}.0{\times}4'.6$, L: $7^{\circ}.5{\times}4'.3$, angular resolution 5'-10') optimized for the observation of diffuse emission of astrophysical radiation. Comet C/2001 Q4 (NEAT) was observed with a scanning survey mode when it was located around the perihelion between 8 and 15 May 2004. Several important emission lines were detected including S I (1425, 1474 ${\AA}$), C I (1561, 1657 ${\AA}$) and several emission lines of CO $A1{\cap}-X1{\sum}+$ system in the L channel. We estimated QCO = ($2.58\;{\pm}\;0.64)\;{\times}\;1028$ s-1 from the production rate of CO 1510 ${\AA}$. We obtained L-channel image which have map size of $5^{\circ}{\times}5^{\circ}$. The image was constructed for the wavelength band of L-channel (1350-1750 ${\AA}$).We also obtained radial profile of S I, C I, CO with line fitting from central coma.

• Journal of the Korean earth science society
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• v.28 no.7
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• pp.847-856
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• 2007

The Planetary nebula NGC 6881 displays quadrupole morphology and it also has a jet feature in its image. We investigated the line profiles of the optical region spectral emission lines, using the Hamilton Echelle Spectrograph (HES) at the Lick observatory. The HES data obtained in this study was the radiation coming from the inner region within the diameter of 4 second of arc. Expansion velocity was obtained, based on the strong emission line profiles of e.g. H, Hel, Hell, [OIII], [NII], [ArIII], [SII], and [SIII}, using the IRAF and StarLink/Dipso reduction packages. The HI recombination lines showed one single peak profile, while the He and forbidden strong lines displayed double peaks. The results of this study show that the outflow velocity of gas increases radially outwards due to the central stellar radiation pressure. It was concluded that three central rings appeared in the HST image are the result of a combined structure of bipolar cones (seen in e.g. HI lines) and a ring (seen in He, [SIII] lines) in projection.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.263-274
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• 2004

High resolution spectroscopic observations of BX And using the BOBS (Bohyunsan Optical Echelle Spectrograph) of Bohyunsan Optical Astronomical Observatory (BOAO) were performod during 26-27, Feb. 2003. From the observations, we obtained 38 line spectra of BX And which cover all phases except the phase interval between $0.^p1$ and $0.^p3$. Both methods of the CCF (Cross-Correlation Function) and BF (Broadening Function) were used to get the radial velocities of primary and secondary components. Both velocities of the primary and secondary stars were calculated with the BF method while only primary velocities were determined with the CCF. Using new radial velocity curves, the maximum radial velocities of the primary and secondary stars were obtained as $K_1=90.1km/s\;and\;K_2=196.6km/s$, respectively. New absolute dimension of BX And was deduced with the combination of our spectroscopic solution with the photometric one of Bell et al. (1990).

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.383-390
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• 2004

We describe the in-flight sensitivity calibration of the Far ultraviolet Imaging Spectrograph (FIMS, also known as SPEAR) onboard the first Korean science satellite, STSAT-1, which was launched in September 2003. The sensitivity calibration is based on a comparison of the FIMS observations of the hot white dwarf G191B2B, and two O-type stars Alpha-Cam, HD93521 with the HUT (Hopkins Ultraviolet Telescope) observations. The FIMS observations for the calibration targets have been conducted from November 2003 through May 2004. The effective areas calculated from the targets are compared with each other.