• 제목/요약/키워드: Nebula

검색결과 131건 처리시간 0.024초

FABRY-PEROT 분광기의 특성과 천문학의 적용 (FABRY-PEROT SPECTROMETER IN ASTRONOMY)

  • 박수종
    • 천문학논총
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    • 제15권spc1호
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    • pp.127-132
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    • 2000
  • The purposes of spectroscopy in astronomy are to measure the radiation flux of the spectroscopic emission or absorption line and to measure the dynamical parameters of the line profile. In order to use an appropriate instrument for the scientific purpose, we need to understand the characteristics of various spectrometers, e.g., a prism spectrometer, a grating spectrometer, and a Fabry-Perot spectrometer (FPS), which are being used in ultra-violet, optical, and infrared bands. The Fabry­Perot spectrometer is not very popular compared to the grating spectrometer, because of its complex and tricky operations. The Fabry-Perot spectrometer, however, can get a two-dimensional image at one exposure, so we can study radiation mechanisms and dynamical properties of extended sources, e.g., clusters, nebula, and galaxies.

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THE $^{13}CO$ DISTRIBUTION AND CORRELATION WITH EXTINCTION IN L134

  • MINN YOUNG KEY;LEE HYE KYUNG
    • 천문학회지
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    • 제29권1호
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    • pp.75-81
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    • 1996
  • We mapped the $^{13}CO$ line in the dark nebula L134 using the 14-m Taeduck radio telescope with a 57 arcsec beam and one beam spacing. The cloud has a spherical shape with an intensity peak ridge extended from the northwest to the southeast directions. The halfwidth and the radial velocity of the lines peak at the region of the cloud center. The radial velocity decreases from the cloud center towards the north and south directions. The integrated line intensity distributions in the space-velocity plane show some structure and a velocity gradient. The $^{13}CO$ and $H_2CO$ clouds and dark clouds are closely related in space in shape, outer boundary, and intensity peak positions. The $^{13}CO$ integrated line intensity is linearly proportional to the visual extinction.

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CO OBSERVATIONS OF A REGION IN THE PERSEUS ARM CONTAINING Hb 12 AND ITS IMMEDIATE VICINITY

  • Cho, Se-Hyung;Kim, K.T.
    • 천문학회지
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    • 제23권2호
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    • pp.85-96
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    • 1990
  • High resolution $^{12}CO$ observations of the region containing the planetary nebula Hb12 were made with the Nobeyama Radio Telescope. These observations reveal that there is no significant CO emission from Hb 12 itself. Near Hb 12, however, the observed regions show a structure of clustered dark clouds whose physical parameters suggest that these clumps would be further fragmented or collapesed. Also found with the high resolution observations is that a few isolated clumps are located away from the main CO feature extended possibly from the galactic plane. For more detail morphologies and velocity structures of the clumps, especially in relation to the large CO complex to which these are likely to be associated, more observations are substantiated.

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Correlation between Photometric Parameters and Morphology of the Proplyds in the Orion Nebula Cluster

  • 김슬기;성환경
    • 천문학회보
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    • 제42권2호
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    • pp.86.1-86.1
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    • 2017
  • 오리온 성운은 지구와 매우 가까이에 있고, 무거운 별이 포함된 성단과 성운이 밀접하게 연관되어 있어, 오리온 성운 성단은 가장 많이 연구된 천체 중 하나이다. 1993년 HST를 이용한 오리온 성운 성단의 관측으로 나이가 어린별을 둘러싼 물질의 실루엣을 처음으로 보았다. 이후 이러한 천체를 원시행성계원반(protoplanetary disk, Proplyd)이라 불렀으며, 그 형태와 구조, 물리적 과정에 대해 꾸준히 연구가 진행되고 있다. 이 연구에서는 지상관측에서 얻은 UBVI 및 Ha 측광 자료와 원시행성계원반을 상호 동정하고, 원시행성계원반의 형태학적 특징과 측광인자의 관련성을 조사하였다. 또한 Spitzer 중적외선 자료와 Natta et al.(2004)의 근적외선 자료를 통합하여, 현재 사용되고 있는 자외선 초과와 근적외선 방출선을 이용한 질량 강착률 등의 해석에서 주의해야 할 천체들이 있다는 것을 발견했다.

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SPECTRAL BEHAVIORS OF Hβ LINE OF CH CYGNI IN A QUIESCENT PHASE

  • 유계화;김강민;이병철;윤태석;이정애
    • 천문학논총
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    • 제19권1호
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    • pp.21-25
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    • 2004
  • We analyzed the high resolution H,6 line spectra of CH Cygni obtained at the Bohyunsan Astronomical Observatory (BOAO) on April 2004. The temporal changes in the $H\beta$ line profiles are reported. We obtained the equivalent widths of the Gaussian components. Using this we estimated the length of the gaseous nebula which emits the $H\beta$ line and the mass loss rate from the star.

The Solar Nebular on Fire: A Solution to the Carbon Deficit in the Inner Solar System

  • 이정은
    • 천문학회보
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    • 제35권1호
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    • pp.91.1-91.1
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    • 2010
  • Despite a surface dominated by carbon-based life, the bulk composition of the Earth is dramatically carbon poor when compared to the material available at formation. Bulk carbon deficiency extends into the asteroid belt representing a fossil record of the conditions under which planets are born. The initial steps of planet formation involve the growth of primitive sub-micron silicate and carbon grains in the Solar Nebula. We present a solution wherein primordial carbon grains are preferentially destroyed by oxygen atoms ignited by heating due to stellar accretion at radii < 5 AU. This solution can account for the bulk carbon deficiency in the Earth and meteorites, the compositional gradient within the asteroid belt, and for growing evidence for similar carbon deficiency in rocks surrounding other stars.

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Gemini Observations of Planetary Nebula Candidates toward the Galactic Center

  • Hong, Jihye;An, Deokkeun;Simpson, Janet P.;Sellgren, Kris;Ramirez, Solange V.;Cotera, Angela S.
    • 천문학회보
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    • 제43권1호
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    • pp.67.1-67.1
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    • 2018
  • We present high-resolution near infrared (IR) spectra of two candidate planetary nebulae (PNe) that were serendipitously found toward the Galactic center (GC). Our spectra obtained using GNIRS on Gemini North reveal strong Br ♑ and He I recombination lines. In one of the targets, we confidently detect Pa ♌ emission. Based on Br ♑ and Pa ♌ lines, we estimate a foreground reddening to be Av=27 mag, which confidently puts this object at the GC distance. Along with the presence of highly excited emission lines such as [S IV], [Ne III], [Ne V], and [O IV] detected in the mid-IR spectra from the Spitzer Space Telescope, and the extended emission in the Pa ♋ narrow-band image from the Hubble Space Telescope, this makes it the first spectroscopically confirmed PN in the GC.

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클라우드 가상화 기법을 이용한 컴퓨터 실습 교육시스템 (Implementation of a Computer Lab System using Cloud Virtualization)

  • 강신심;이봉환
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2012년도 추계학술대회
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    • pp.351-354
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    • 2012
  • 클라우드 컴퓨팅의 핵심은 대규모 컴퓨팅 리소스를 유기적으로 연결시켜 효율적으로 사용하게 하는 것이다. 본 논문에서는 오픈 소스 기반의 클라우드 컴퓨팅 가상화 기법을 이용한 가상 컴퓨터 실습실을 설계하고 구현하여 교육현장에서 실습 장비의 노후나 소프트웨어의 잦은 업그레이드로 인한 문제점을 개선할 수 있도록 하였다.

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OBSERVATIONS OF THE $J=1{\rightarrow}0$ TRANSITIONS OF $^{12}CO,\;^{13}CO\;and\;C^{18}O$ TOWARD OMC-1

  • SONG H. J.;CHUN M. S.;MINH Y. C.
    • 천문학회지
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    • 제26권1호
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    • pp.65-72
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    • 1993
  • Using the Daeduk Radio Telescope, we have observed $J=1\rightarrow0$ transitions of 1$^{12}CO,\;^{13}CO\;and\;C^{18}O$ toward OMC-l. The column densities of $1\~5\times10^{17}\;cm^{-2}\;and\;1\~3\times10^{16}\;cm^{-2}$ have been derived, for $^{13}CO$ and $C^{18}O$, respectively, in the $11'\times11'$ region centered at Orion - KL. The double isotope ratio $[^{13}CO]/[C^{18}O]$ was found to be larger than the cosmic abundance ratio by factors of $2\~10$ which may result from the chemical fractionation effect.

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眼病의 外治法에 대한 文獻的 考察 (A Literatual Study on the external treatment of eye diseases)

  • 서형식;이용구;노석선
    • 한방안이비인후피부과학회지
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    • 제10권1호
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    • pp.185-208
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    • 1997
  • A Literatual Study on the external treatment of eye diseases, the result were as follows. 1. The external treatment of eye diseases used eyedrops(點,滴), steam bath(熏), washing(洗), plaster(敷). 2. Eyedrops used filterated decoction. 3. Eye diseases used Bomeolum(永片), Coptidis Rhiwma(黃連), Angelicae gigantis Radix(當歸) with clearing away heat and toxic materials, clearing away swelling, pain, ithing and convulsion, clearing away nebula 4. Eye diseases used B-1(晴明), B-2(찬竹), Tae-Yang(太陽), S-1(承泣), G-1(瞳子료), S-2(四白), TE-23(絲竹空), Eo-Yo(魚腰), G-14(陽白), Gu-Hu(球後), G-20(風池), B-18(肝兪), LI-4(合谷), Liv-3(太衡, B-23(腎兪), G-37(光明), Liv-2(行間), GV-23(上星), and S-36(足三里).

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