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1968년 ~ 2024년까지 1,211 건의 한국천문학회지를 격월간 확인하실 수 있습니다.
- The Korean Astronomical Society (The Korean Astronomical Society)
- 계간 (Quarterly)
- ISSN : 1225-4614 (ISSN : 1225-4614)
1225-4614
- DB구축현황 : 1,211건 (DB Construction : 1,211 Articles)
총 게시글 1,211건
페이지 86/122
851
- XU CHONGMING
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.17-18
- 1996
- 원문 바로보기
COBE's results on the anisotropy of the cosmic microwave background radiation (CMBR) is discussed. Some ambiguities in the linear GI cosmic perturbation theory are clarified. The problem of the last scattering surface and the deficiencies of the linear cosmic perturbation theory are mentioned. The possible ways to overcome the theoretical difficulties are discussed also.
852
- PARK BYEONG-GON
- Journal of the Korean astronomical society = 천문학회지
- 29, n.1
- pp.63-73
- 1996
- 원문 바로보기
The previous study of chemical evolution of the Galaxy is extended to the radial properties of the Galactic disk. The present model includes radial dependency of the time-dependent bimodal IMF, radial flow of material in the disk, and the change of type I supernova explosion rate with radial distance from the disk center as model parameters and observed gas and stellar density distributions and metallicity abundance gradient as observational constraints. The results of two models in this study explain the observed gas and stellar density distributions well, with the slope of the gas density gradient in the region of 4.5 kpc<r<12kpc as -0.136dex/kpc in model <TEX>$Y_1$</TEX> and -0.123dex/kpc in model <TEX>$Y_2$</TEX>, respectively, which fit well the observed gradient of -0.l1dex/kpc. The abundance gradient reproduced in model <TEX>$Y_1$</TEX> is getting flatter with decreasing radius, while that in model <TEX>$Y_2$</TEX> is getting steeper, which fits better the observed abundance gradient. This result shows the necessity of exponentially increasing type I supernova explosion rate with decreasing radius in order to explain the observed abundance gradient in the disk. The fitness of observed density distribution and star formation rate distribution justifies the reliability of time-dependent bimodal IMF as a compound quantitative chemical evolution model of the Galaxy. The temporal variations of metallicity gradients for carbon, nitrogen and oxygen are also shown.
853
- MATSUHARA H.
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.171-172
- 1996
- 원문 바로보기
We present the results of an rocket-borne observation of far-infrared [CII] line at 157.7 <TEX>${\mu}m$</TEX> from the diffuse inter-stellar medium in the Ursa Major. We also introduce a part of results on the [CII] emission recently obtained by the IRTS, a liquid-helium cooled 15cm telescope onboard the Space Flyer Unit. From the rocket-borne observation we obtained the cooling rate of the diffuse HI gas due to the [CII] line emission, which is <TEX>$1.3{\pm}0.2 {\times} 10^{-26}$</TEX> <TEX>$ergss^{-1} H^{-1}_{atom}$</TEX>. We also observed appreciable [CII] emission from the molecular clouds, with average CII/CO intensity ratio of 420. The IRTS observation provided the [CII] line emission distribution over large area of the sky along great circles crossing the Galactic plane at I = <TEX>$50^{\circ}$</TEX> and I = <TEX>$230^{\circ}$</TEX>. We found two components in their intensity distributions, one concentrates on the Galactic plane and the another extends over at least <TEX>$20^{\circ}$</TEX> in Galactic latitude. We ascribe one component to the emission from the Galactic disk, and the another one to the emission from the local interstellar gas. The [CII] cooling rate of the latter component is <TEX>$5.6 {\pm} 2.2 {\times}10$</TEX>.
854
- BROSCH NOAH
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.421-423
- 1996
- 원문 바로보기
855
- TSAY WEAN-SHUN
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.409-410
- 1996
- 원문 바로보기
Speckle Interferometer equipped with an ITT intensified CCD have been used on the NCUO ( National Central University Observatory, Taiwan) 24-inch telescope for studying the orbits of bright binary systems selected from the Yale's Bright Star Catalogue. The high resolution and high sensitivity ITT intensified solid state video camera ( F4577 ) has external gain and gate control functions which will simplify the design of the speckle camera and allow us to do precise speckle photometry. The goal of this project is trying to study the bright binary systems with separations between the average size of seeing disk and the diffraction limit of the 24-inch telescope. Recently some observing data have been reduced and compared with the other teams' results. We are now improving the data reduction technology and trying to use real time observing mode on the monthly routine observation.
856
- KANG HYESUNG
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.271-272
- 1996
- 원문 바로보기
Assuming that particles can be accelerated to high energies via diffusive shock acceleration process at the accretion shocks formed by the infalling flow toward the clusters of galaxies, we have calculated the expected spectrum of high-energy protons from the cosmological ensemble of the cluster accretion shocks. The model with Jokipii diffusion limit could explain the observed cosmic ray spectrum near <TEX>$10^{19}eV$</TEX> with reasonable parameters and models if about <TEX>$10^{-4}$</TEX> of the infalling kinetic energy can be injected into the intergalactic space as the high energy particles.
857
- RIAZI N.
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.283-284
- 1996
- 원문 바로보기
Wormhole solutions of general theory of relativity are known to violate energy conditions. We have considered the possibility of having wormhole solutions in Brans-Dicke theory which is the prototype of scalar-tensor theories of gravity.
858
- GRIV EVGENY
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.355-355
- 1996
- 원문 바로보기
859
- KURTANIDZE OMAR M.
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.129-131
- 1996
- 원문 바로보기
The results on the deep low dispersion (1250 <TEX>${\AA}$</TEX>/mm at <TEX>$H_r</TEX>, <TEX>$30^{\circ}$</TEX> < I < <TEX>$165^{\circ}$</TEX>, <TEX>$195^{\circ}$</TEX> < I < <TEX>$210^{\circ}$</TEX>, [b] < <TEX>$5^{\circ}$</TEX>; 7000<TEX>${\AA}$</TEX>/mm at A band, <TEX>$50^{\circ}$</TEX> < I < <TEX>$115^{\circ}$</TEX>, b=<TEX>$0^{\circ}$</TEX>, b=<TEX>${\pm}3.5^{\circ}$</TEX>) spectral surveys of the MILKY WAY are presented. More than 2250 carbon stars were identified among them 1440 new ones. The C/M5+ ratio increases from 0.02 to 0.3 when longitude varies from <TEX>$30^{\circ}$</TEX> to <TEX>$210^{\circ}$</TEX>. On the basis of A GENERAL CATALOG OF GALACTIC COOL CARBON STARS the surface distribution of carbon stars has been studied.
860
- CHO YOUNG JUN
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.79-80
- 1996
- 원문 바로보기
We performed CCD surface photometry in B,V,R and I filters for three southern spiral galaxies:ESO598-G009,NGC1515 and NGC7456. Isophotal map, luminosity profile, ellipticity profile and position angle profile were obtained for these galaxies using SPIRAL package. The results show that one of the galaxies, ESO598-G009 has relatively large bulge component and changes in position angle due to spiral arms. The NGC7456 has very small bulges; and the isophotal map of the NGC1515 shows that it is a typical spiral galaxy with bar.