• Title/Summary/Keyword: PKAS

검색결과 579건 처리시간 0.42초

격변 변광성 : 확률적 중력파동배경의 샘 (CATACLYSMIC VARIABLES : SOURCES OF STOCHASTIC GRAVITATIONAL WAVE BACKGROUND)

  • 송두종
    • 천문학논총
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    • 제22권4호
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    • pp.113-132
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    • 2007
  • On the framework of stochastic gravitational wave background(SGWB) by compact binary systems, we studied the strain spectra of SGWB produced by cosmological cataclysmic variables(CV). For this we reviewed the empirical properties of CVs by using newly published CV catalogue and calculated the cosmological densities of CVs considering the galaxy luminosity function and cosmic stellar birth rate function. Assuming the secular evolution of CVs, we calculated the time scale of CV gravitational wave(GW) radiation and derived formulae for the strain spectra of SGWB by cosmological CVs.

공생형 별 AG PEGASI의 고해상 스펙트럼 (HIGH RESOLUTION SPECTRUM OF SYMBIOTIC STAR AG PEGASI)

  • 유계화
    • 천문학논총
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    • 제21권2호
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    • pp.35-42
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    • 2006
  • We report a high resolution spectrum of AG Pegasi observed at Bohyunsan Optical Astronomy Observatory (BOAO) on October 2, 2004. Some of permitted emission lines, for example H I, He I, He II, Fe II and Ti II were observed in the spectrum of AG Pegasi in 2004. Lines presented in the longer wavelength region than $6500{\AA}$ are identified. And radial velocities for each element are measured. Then we carefully discuss the geometrical feature of AG Pegasi in October 2004.

중대형 망원경을 이용한 관측연구 현황 (SURVEY ON THE OBSERVATIONAL RESEARCH ACTIVITIES USING MID-TO-LARGE SIZE TELESCOPES)

  • 우종학
    • 천문학논총
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    • 제25권4호
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    • pp.107-112
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    • 2010
  • By joining the Giant Magellan Telescope (GMT) project, Korean astronomers will get 10% of the GMT time, starting in the late 2010s. To prepare the GMT era, it is important to evaluate the current observational research activities. We surveyed the research programs performed by domestic astronomers during 2007A - 2010A period, using optical/near - IR telescopes with a medium to large aperture mirror (larger than 4 m). We describe the method and criteria of the survey, and present the results of the analysis based on the collected data.

CENSUS AND ANALYSIS OF GALACTIC MOLECULAR CLOUDS

  • HOJAEV, A.S.
    • 천문학논총
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    • 제30권2호
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    • pp.107-108
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    • 2015
  • In this project, all available databases of molecular and gas-dust clouds in the Galaxy were cross-identified by taking into account available properties, including position, angular dimensions, velocity, density, temperature and mass. An initial list of about 7000 entries was condensed into a cross-identified all-sky catalogue containing molecular and gas-dust clouds. Some relationships were studied between the main physical features of clouds. Finally, we prepared a complex observing program and address future work for filling in the gaps.

ORGANIC DUST IN THE INTERSTELLAR MEDIUM

  • KWOK, SUN
    • 천문학논총
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    • 제30권2호
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    • pp.155-158
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    • 2015
  • The traditional view of dust in the interstellar medium is that it is made of graphite and silicates. In this paper, we discuss the evidence for complex organics being a major component of interstellar dust. Comparison between astronomical infrared spectra and laboratory spectra of amorphous carbonaceous materials suggests that organics of mixed aromatic-aliphatic structures are widely present in circumstellar, interstellar, and galactic environments. Scenarios for the synthesis of these compounds in the late stages of stellar evolution are presented.

THE IAU TODAY AND THE ASIAN-PACIFIC REGION

  • KAIFU, NORIO
    • 천문학논총
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    • 제30권2호
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    • pp.39-43
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    • 2015
  • We overview and discuss the IAU today from the viewpoint of its regions based on historical and statistical data, and consider the status and future of astronomy in the Asian-Pacific region. New activities of the IAU, the Office of Astronomy for Development (OAD) and the Office for Astronomy Outreach (OAO) for the future evolution of astronomy are introduced. We also review the recent developments in astronomy in the Asian-Pacific region, and emphasize the importance of regional cooperation and coordination for the future.

LUNAR ECLIPSE COMPUTATION IN INDIAN ASTRONOMY WITH SPECIAL REFERENCE TO SIDDHNTIC TEXTS

  • CHATTERJEE, SOMENATH
    • 천문학논총
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    • 제30권2호
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    • pp.713-714
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    • 2015
  • Indian astronomical texts have records of lunar astronomy since the Puranic age. In the Vednga Jyotia (1350 B CE), the algorithm for computing eclipses is not found. This phenomenon was interpreted in the Siddhntic texts as the occurrence of Vyatipati Yoga. This paper attempts to explain the computing and observational method found in astronomical texts of Siddhntic period.

THE TeV GAMMA-RAY MILKY WAY

  • ROWELL, GAVIN
    • 천문학논총
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    • 제30권2호
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    • pp.553-557
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    • 2015
  • This review summarises the current status of the Galactic TeV ($10^{12}$ eV) gamma-ray source population. It also briefly looks at the future beyond the current generation of TeV gamma-ray facilities, and highlights the role of the interstellar medium (ISM) in helping to resolve some of the challenges in interpreting the wealth of results which have been found in recent years.