공생별의 고분산 분광선 연구 - CI Cyg 방출선

형식 ( Siek Hyung ),이성재 ( Seong Jae Lee ),한경아 ( Kyoung A Han ) 충북대학교 과학교육연구소 2015 과학교육연구논총 Vol.30 No.2

1998년 9월 12일 (위상 □ = 0.90)와 2002년 8월 12일 (□ = 0.47)에 Aller 와 Hyung이 관측한 Lick 천문대의 HES 고분산 분광 자료, 그리고 2009년 10월 21일 (□ = 0.54) 보현산 천문대에서 형식과 이성재가 관측한 BOES 고분산 분광자료를 이용해 공생별 CI Cyg를 연구하였다. 방출선 윤곽과 선세기는 관측시기의 별 위상에 따라 변화를 보였다. 우리는 O I, O III, [O I], [O III], N III, [S III], Si II 선들의 윤곽을 제시하고, 이를 통해 공생별CI Cyg를 구성하는 뜨거운 백색왜성과 M4 분광형을 가진 차가운 적색거성 주변 가스의 물리적 조건에 대해 논의 하였다. We investigated the high dispersion HES data of the Symbiotic star CI Cyg observed at Lick Observatory on September 12th, 1998 (phase □ = 0.90) and on August 12th, 2002 (□ = 0.47) by Aller and Hyung. along with the BOES data observed at Bohyunsan Observatory on October 21st, 2009 (□ = 0.54) by Hyung and Lee. The emission line profiles and their line intensities show change depending on the phase of different observing periods. We present the line profiles of O I, O III, [O I], [O III], N III, [S III], and Si II and discuss the physical condition of the nebulous gas surrounding two components of the symbiotic star CI Cyg, i.e., a small hot white dwarf and a cold M4 type red giant star.

1.8m 망원경을 이용한 방출선 천체 연구

형식,김강민,HYUNG SIEK,ALLER LAWRENCE H.,KIM KANG-MIN 한국천문학회 2000 天文學論叢 Vol.15 No.suppl1

The emission line objects such as planetary nebulae, symbiotics, gaseous nebulae, HII regions, novae, supernovae, SNRs, nearby spiral galaxies, dIrr, dE, and nearby active galactic nuclei, would be goldmines for us to dig with the 1.8m bohyunsan optical (BOAO) telescope. We discussed the importance of strategically important diagnostic lines and atomic constant calculation for a study of Galactic and extragalactic emission objects. The scientific background on a spectrometer development history is briefly presented and spectroscopic research areas other than the emission objects are also summarized.

행성상성운 NGC 7027의 물리적 특성 분석 -고이온화 분광선 연구

형식 ( Siek Hyung ),이성재 ( Seong Jae Lee ) 충북대학교 과학교육연구소 2015 과학교육연구논총 Vol.31 No.1

We investigated the high dispersion spectra of the planetary nebula (PN) NGC 7027 which had been observed with the Bohyunsan Optical Echelle Spectrograph (BOES) on October, 20, 2009. Unlike the other lines that show double Gaussian line profiles, the high excitation lines of [Ar IV], [Ca V] and [Fe VIIJ, display a secondary fast component in the blue-shift side. We derived the expansion velocity of 38.35±3.32 kms-1 responsible for the recently formed sub-shell structure, much faster than those of the main shell, 17.74±1.69 kms-1. The very young PN NGC 7027 might be still in an earlier stage of its shaping as a PN along with the fastly expanding recent ejecta from the central star. We discuss the implication of the swiftly expanding sub-shell structure: the physical condition, and the rough estimation of its age.

천체까지의 거리는 어떻게 구할까?

형식 ( Siek Hyung ) 한국현장과학교육학회 2007 현장과학교육 Vol.1 No.1

하늘과 지구의 크기, 즉 우주에 대한 문제는 선사 이래 인류가 가장 궁금하게 생각하는 문제 중의 하나이다. 과학이 발달하면서 과학적인 탐구결과 밝혀진 증거에 근거하여 천체의 크기나 우주의 한계를 구체적인 숫자로 제시해도, 학생과 일반사람이 그 의미를 피부에 닿게 이해하기란 쉽지 않다. 교육현장에서 교사가 주어진 자료값의 변화에 따라 우주관이 어떻게 달라지고, 종교관에는 어떠한 영향이 있는지를 직접적으로 비교·적용하면서 쉽게 설명하는 것이 필요하다. 그러한 노력이 있지 않으면, 과학적인 결과는 단지 숫자일 뿐 상상할 수 없는 것이리라는 것 이외에 큰 의미를 주지 못한다. 이 연구에서는 고대 천문학적 지식을 소개하고 중학교 학습에서 활용할 수 있는 예시를 제시하여 어떻게 천체까지의 거리를 구하는지를 숙지하게 하여, 현장 학습에 도움이 되고자 하였다. 우주의 크기에 대한 인류의 이해의 역사나 과학적인 노력을 보여주는 좋은 한 예가 바로 제 7차 중학교 2학년 과정에 나오는 지구의 크기 측정에 관한 단원이다. 2학년 과정을 보면 2,200년 전, 에라토스테네스가 시에네와 알렉산드리아에서 정오에 관찰된 태양의 고도자료를 이용하여 지구의 크기를 계산한 결과가 나온다. 만일 지구가 둥글지 않고 편평하다면 어떠한 결과가 나올까? 이 연구에서는 동시대에 중국에서도 회남자에서 유사한 사실을 발견하고 직시하였음을 고찰하였다. 또한 이러한 자료를 활용하여, 즉 지구가 편평하다는 가정 아래 당시 중국인들이 태양까지의 높이를 어떻게 계산하였는지를 살펴보고, 이러한 사실을 어떻게 현장 학습에 활용할 수 있는지 예시를 제시하였다. 또한 현대 천문학에서 비슷한 원리를 사용하여 천체까지의 거리를 어떻게 구하고, 이에서 발전한 다른 예가 무엇인지를 간단히 논의하였다. Since the prehistoric period, one of the human's most intriguing questions is to know the distance of the heaven and earth size. It is still not an easy matter for students or the public to visualize them meaningful, even if scientists are guided with the real figures, the scale of the celestial objects and the Universe based on the scientific research. Hence, it would be necessary for teachers to guide them, with some direct comparative examples which may change their view on the Universe or the religious belief. Without teacher's such clever role, the scientific discover could sometimes be nothing other than a simple dull figure which is beyond the imagination. In this study, we investigate the ancient Astronomical endeavor on the determination of celestial distances, of which knowledge can be useful in the middle school teaching classes. A good example which shows the ancient Astronomers' endeavor to figure out the Universe extent is the circumference measurement of the Earth, given in the 8th grade textbook of the 7th National Curriculum. About 2,200 year ago, Eratosthenes (276BC-194BC) analyzed the altitude difference (measured at noon) between Alexandria and Syene, and found the size of the Earth. If the Earth is not round and flat instead, what kind of scientific discovery will come out from such observed data? In this study, we investigate the case of the China Han dynasty of the same period with Greece, who also observed the similar difference between north and south provinces. On the other hand, the Chinese tried to determine the sky height where the Sun located at noon, assuming the Earth's flatness. We discuss the Western Han dynasty (about 200 BC) case and provide the tutorial an example for middle school students's learning classes. We also review modern celestial distance determination methods, e.g. from triangular parallax to other evolved developed system.

HII 영역 분광자료를 통한 M31과 M33의 화학원소 결정

한수련,형식,박홍서,이우백,HAN SOO RYEON,HYUNG SIEK,PARK HONG-SUH,LEE WOO-BAlK 한국천문학회 2001 Journal of The Korean Astronomical Society Vol.34 No.2

Chemical evolution of galaxies can be understood by studying the spatial distribution of heavy elements. We selected two nearby galaxies, M31 and M33 and investigated spectrum of their HII regions: a) the elec-tron densities have been derived from the [S II] 6717/6731 ratio along with the most recent atomic constants (Hyung & Aller 1996); b) the electron temperatures were determinated from the Pagel's empirical method. Nebula Model (Hyung 1994) has been employed to predict the spectral line intensities which gives the proper chemical abundances. The model would predict the line intensities correctly only when various input parameters such as the effective central star temperatures, gravity log g, model atmosphere as well as the geometry and the nebula physical condition are appropriate. Thus, the determination of chemical abundances of O, S, N of the two nearby galaxies M31 and M33 has been done, which shows a radial dependance of O/H and N/H: decrease with the distance, or increasing electron temperature due to the elemental deficiency. Abundances of M31 appear to be enhanced than those of M33.

23개 공생별의 분광학적 특성

김여정,형식,KIM YEOJEONG,HYUNG SIEK,ALLER LAWRENCE H. 한국천문학회 2000 天文學論叢 Vol.15 No.suppl1

Symbiotic stars are known as binary systems with both cool and hot components with enshrounding nebulous gas. The cool component, M-type giant, is presumably loosing its mass into a hot white or main sequence companion star through the inner Lagrangian point. The lines emit from the ionized nebulous region around the hot star while the mass loss or accretion activity is believed to be the main cause of sudden variation of the continuum and line fluxes. We selected 17 symbiotics for which the emission line fluxes were measured from the IUE SWP, LWR data, to find variability of spectrum. We also investigated the periodic variation of emissions or eclipsing effect from the IUE lines. All of our symbiotics show very high electron densities in the emission regions. For other optical symbiotics, the observations had been carried in 1999 with BOAO mid-resolution spectrometer. We classified symbiotics based on their outburst activities, or emission line characteristics, i.e., $OVI{\lambda}6830.\;The\;OVI{\lambda}6830$ emission lines are also found in S-type symbiotics, which have been known as charateristics of D-types.

보현산 천문대의 대기 소광계수

김강민,손동훈,형식,윤태석,Kim, Kang-Min,Son, Dong-Hoon,Hyung, Siek,Yoon, Tae-Seog 한국천문학회 1997 天文學論叢 Vol.12 No.1

Detailed low spectral resolution observations of the spectrum have been made for three early spectral type standard stars, HR718, HR1544, HR3454, respectively, for the wavelength region 4,300 A to 7,500 A, using the Bohyunsan Optical Astronomy Observatory (BOAO) Middle- Dispersion Spectrograph. These standard stars were chosen from well-known bright northern standard stars. All of the observed long slit spectral data has been reduced and analyzed using the IRAF reduction procedure. The derived extinction coefficients are compared with the other observatory result. The derived value can be used in the determination of flux calibration of BOAO spectroscopic observation. However, until the high quality data are secured from a new series of observation in the blue region and are re-analyzed together, the extinction coefficients below the 4,000 A wavelength remains unknown.

보현산천문대 고분산 에셀분광기(BOES) 제작

김강민,장정균,천무영,박병곤,형식,한인우,윤태석,KIM KANG-MIN,JANG JEONG GYUN,CHUN MOO-YOUNG,PARK BYEONG-GON,HYUNG SIEK,HAN INWOO,YOON TAE SEOG,VOGT STEVEN S. 한국천문학회 2000 天文學論叢 Vol.15 No.suppl1

The BOES (BOAO Echelle Spectrograph), a fiber-fed echelle spectrograph of the BOAO 1.8 m telescope, has been designed and now is being manufactured. The BOES follows a white pupil design collimated with two off-axis parabolic mirrors. The 136mm collimating beam leaving the 41.59 grooves/mm R4 echelle grating is refocused near the narrow folding mirror. Through the two cross-disperser prisms and $\phi250 mm(f/1.5)$ transmission camera, the beam images on EEV $2k\times4k$ CCD. The BOES can take the wavelength range of 3700 to $10100{\AA}$ at a single spot with spectral resolution R = 20000 to 40000 depending on the fiber set employed. We describe the key sciences and performance, current status of construction, and future plan of the BOES.

HALE-BOPP 혜성의 CN, C2 분자 생성율

손동훈,김상준,김주현,김강민,성언창,형식,Son, Dong-Hoon,Kim, Sang-Joon,Kim, Joo-Hyun,Kim, Kang-Min,Sung, Eon-Chang,Hyung, Siek 한국천문학회 1997 天文學論叢 Vol.12 No.1

We obtained the CN($\Delta_V=0$) and $C_2(\Delta_V=0,\;\pm1$) spectra of comet Hale-Bopp(C/1995 O1) at the Kyunghee Observatory and Bohyunsan Astronomical Observatory between March 7 and May 12, 1997 The fluxes for each molecular band were measured and then the production rates and column densities of CN and $C_2$ were calculated using a simple model. The resultantproduction rates of CN and $C_2$ are logQ(CN)=27.4 at r=0.94 AU(preperihelion) and $logQ(C_2)=27.3$ at r=0.94 AU(postperihelion), respectively.

공생별 BOES/HES의 고분산 분광 관측 자료 비교연구

형식 충북대학교 과학교육연구소 2003 과학교육연구논총 Vol.19 No.1

With the newly constructed Mt. BohyunSan fiber-fed high echelle dispersion spectrograph (BOES), we observed several planetary nebulae and symbiotic stars. With the BOES, we failed to detect strong emission lines such as [OIII] 5007 for the case of planetary nebulae, whereas only a few strong lines were weakly detected for brighter symbiotic stars. By comparing the BOES spectral data with those already observed with the Hamilton echelle sepctrograph (HES) for the same objects, we estimated the wavelength dependent BOES efficiencies and compared with those of the HES: the BOES overall throughput is about 3%, and somewhat lower in the short ward of 4500Å. We discuss the current situation of the BOES and make a few suggestions on how to improve its efficiency.