Volume 7 Issue 2
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Morphological luminosity parameters
$(\mu_e,\;r_e,\;\mu_0,\;\alpha^{-1})$ and D/B were estimated from the decomposition of surface brightness distributions of 28 extra galaxies. Decomposition was made using the standard non-linear least square fitting method and we used the seeing convolved model to get the central brightness of these galaxies. Masses and$M/L_B$ were calculated using rotational velocities of these galaxies from the fitting to the generalized Toomre's mass model. -
Stars in M 68 from the observed-magnitude diagrams with CCD were integrated to find any radial gradient. The result shows that M 68 has a slightly bluer core. The main cause of these calculated radial color variations seems to come from the random distribution of ginants.
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전자 beam이 중성 plasma계에 들어왔을 때의 상호작용을 이차원 정전 model을 사용하여 수치계산을 한 결과 beam의 밀도변화에 따라 상호작용이 큰 변화를 보이는 것으로 나타났다. beam 전자의 밀도가 주변 전자의 밀도보다 낮을 때는 많은 양의 beam들이 주변 plasma와의 상호작용을 통해 위상공간에서 vortex 구조를 보이며 입사지역으로부터 멀리 진행할 수 있었던 반면 beam 전자들의 밀도가 높을 때는 대부분의 beam 전자들이 입사지역으로 되돌아오는 희귀전류를 형성하였다. 이 때 자기장의 게기에 따라 전자보다 훨씬 질랴이 큰 ion들이 가속될 수도 있으며 전자들의 전파와 상호작용의 양상이 크게 바뀔 수 있는 것으로 나타났다.
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Luminosity profiles and dynamical parameters of 12 globular clusters in the Large Magellanic Cloud(SB(s)m) are obtained from the concentric aperture photoelectric photometry of 3 different aged clusters and the collected photometric data of 9 clusters. The total masses of the globular clusters are calculated using the equation
$M_\bigoplus$ =${Mr_t}^j(4\Omega^2-k^2)$ , which is derived from the theroetical rotation curve for the exponential disk(Chun 1978). These masses lie between$0.3\times10^4$ and$15.8\times10^4M_\bigoplus$ . From the determined total mass and luminosity, the mass-to-luminosity ratios are also derived. The M/L ratio of a cluster increases with the cluster age ; about 0.03 for the youngest clusters(SWB I) and about 0.24 for the oldest clusters (SWB VII). There is a difference in M/L by a factor of 10 between the galactic globular clusters and the old globular clusters in the LMC.