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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 92/122
911
- KOZHANOV T. S.
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.27-29
- 1996
- 원문 바로보기
We describe the formation of large-scale inhomogeneous structure of expa-nding Universe on the basic of two components system-usual nonrelativistic particles and dark matter, with taking into account their interaction.
912
- KOZAI YOSHIHIDE
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.351-354
- 1996
- 원문 바로보기
In this paper it is explained how most of asteroids can avoid very close approach to Jupiter, to the earth for earth orbit crossing asteroids, and to Neptune for Kuiper-belt asteroids by mechanisms which work also for Neptune-Pluto system. In fact the mutual distance of the planets cannot become very small as the critical argument librates around <TEX>$180^{\circ}$</TEX> because of 2:3 mean motion resonance and the argument of perihelion of Pluto librates around <TEX>$90^{\circ}$</TEX>. And it is found that among nearly 40 Kuiper-belt asteroids discovered in recent years <TEX>$40\%$</TEX> have orbits similar to Pluto. For main-belt asteroids the distribution with respect to the semi-major axes has peculiar characteristics and the author tries to explain how their peaks and gaps are created. It is also found that <TEX>$30\%$</TEX> of 80 earth orbit crossing asteroids which have minimum perihelion distances less than 1.04AU have no chance to collide with the earth. Still <TEX>$30\%$</TEX> of them have a few probability to collide with the earth as they have dynamical characteristics of short-periodic comets.
913
- WIRAMIHARDJA SUHARDJA D.
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.265-266
- 1996
- 원문 바로보기
914
- WU XUE-BING
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.231-232
- 1996
- 원문 바로보기
The local instabilities of accretion disks were extensively studied, with the considerations of radial advection, thermal diffusion and different disk geometry, dominated pressure and optical depth. Two inertial-acoustic modes in a geometrically thin, radiative cooling dominated disk depart from each other if very little advection is included. A geometrically slim, advection-dominated disk is found to be always stable if it is optically thin. However, if it is optically thick, the thermal diffusion has no effect on the stable viscous mode but has a significant contribution to enhance the thermal instability.
915
- KUBOTA JUN
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.329-330
- 1996
- 원문 바로보기
916
- LEE HYUNG MOK
- Journal of the Korean astronomical society = 천문학회지
- 29, n.1
- pp.19-30
- 1996
- 원문 바로보기
We have examined consequences of strong tidal encounters between a neutron star and a normal star using SPH as a possible formation mechanism of isolated recycled pulsars in globular clusters. We have made a number of SPH simulations for close encounters between a main-sequence star of mass ranging from 0.2 to 0.7 <TEX>$M_\bigodot$</TEX> represented by an n=3/2 poly trope and a neutron star represented by a point mass. The outcomes of the first encounters are found to be dependent only on the dimensionless parameter <TEX>$\eta'{\equiv}(m/(m+ M))^{1/2}(\gamma_{min}/R_{MS})^{3/2}(m/M)^{{1/6)}$</TEX>, where m and M are the mass of the main-sequence star and the neutron star, respectively, <TEX>$\gamma_{min}$</TEX> the minimum separation between two stars, and <TEX>$R_{MS}$</TEX> the size of the main-sequence star. The material from the (at least partially) disrupted star forms a disk around the neutron star. If all material in the disk is to be acctreted onto the neutron star's surface, the mass of the disk is enough to spin up the neutron star to spin period of 1 ms.
917
- UMEDA HIDEYUKI
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.23-24
- 1996
- 원문 바로보기
We reexamined CDM texture large-scale structure (LSS) formation model. We confirmed that texture model is consistent with 4-year COBE data both in an open and a critical matter density (<TEX>${\Omega}_0$</TEX> = 1) universes, and then obtained normalization for density perturbation power spectrum. We next compare the power spectrum with LSS observation data. Contrary to the previous literature, we found that texture model matches with these data in an open universe no better than in an <TEX>${\Omega}_0$</TEX> = 1 universe. We also found that the model is more likely to fit these data in a cosmological constant dominated (<TEX>$\Lambda-$</TEX>) universe.
918
- CHITRE S. M.
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.31-33
- 1996
- 원문 바로보기
The role of gravitational lenses as valuable tools for astrophysics and cosmology is highlighted.
919
- PENG QIUHE
- Journal of the Korean astronomical society = 천문학회지
- 29, n.suppl1
- pp.69-70
- 1996
- 원문 바로보기
920
- ANN HONG-BAE
- Journal of the Korean astronomical society = 천문학회지
- 29, n.2
- pp.255-268
- 1996
- 원문 바로보기
We present VR CCD photometry and long-slit spectroscopy of a late type spiral galaxy NGC 7678. The grey scale images and isophotal maps illustrate the presence of a weak bar from which spiral arms emerge. There are many HII regions along the spiral arms, but bright giant HII regions are more concentrated in the massive southern arm. The bright compact nucleus of NGC 7678 is bluer than bulge and bar. The spectral features of the nucleus and HII regoins are very similar but the nuclear spectra shows higher <TEX>$[NII]{\lambda}6583/H_\alpha$</TEX> than those of the HII regions. The nucleus of NGC 7678 seems to be intermediate type between HII region nulcei and LINERs by the ratio of <TEX>$[NII]{\lambda}6583/H_\alpha$</TEX>, but it is more likely to be HII region-like nucleus if we consider the <TEX>$[NII]{\lambda}6716,6731/H_\alpha$</TEX> together. The star formation rate is estimated to be about <TEX>$0.2 M_\bigodot\;yr^{-1}$</TEX> based on the <TEX>$H_\alpha$</TEX> flux.