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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Astronomy and Space Sciences
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Journal DOI :
The Korean Space Science Society
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Volume & Issues
Volume 7, Issue 2 - Dec 1990
Volume 7, Issue 1 - Jun 1990
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CORRELATION AMONG MORPHOLOGICAL CLASSIFICATIONS AND MASS TO LUMINOSITY (M/L) RATIONS OF EXTRA GALAXIES
Chun, Mun-Suk ; Na, Kyung-Sun ;
Journal of Astronomy and Space Sciences, volume 7, issue 2, 1990, Pages 73~103
Morphological luminosity parameters
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
were calculated using rotational velocities of these galaxies from the fitting to the generalized Toomre's mass model.
RADIAL COLOR GRADIENT IN A GLOBULAR CLUSTER 1. M68
Yi, Su-Kyoung ; Chun, Mun-Suk ;
Journal of Astronomy and Space Sciences, volume 7, issue 2, 1990, Pages 105~111
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.
TWO DIMENSIONAL SIMULATION OF BEAM INJECTION INTO NEUTRAL PLASMA
Journal of Astronomy and Space Sciences, volume 7, issue 2, 1990, Pages 113~123
Two dimensional electrostatic model was used to investigate the interactions between beam electron and neutral plasma. It was found that results heavily depend on the beam density. When the beam electron density is lower than the ambient plasma beam density, many beam electrons exhibit vortex structure through beam-plasma interactions and can propagate into the ambient plasma easily from the injection area. On the other hand, when the beam density larget than that of the neutral ambient plasma, it was found that most of the beam electrons constitute return current and ion with much larger mass than that of the electron can be accelerated according to the magnetic field strength. Furthermore, as external field strength varies, it was found that propagation and interaction of the beam can show large dependence on it.
MASS TO LUMINOSITY RATIONS OF SOME CLUSTERS IN THE LARGE MAGELLANIC CLOUD
Sohn, Young-Jong ; Chun, Mun-Suk ;
Journal of Astronomy and Space Sciences, volume 7, issue 2, 1990, Pages 125~139
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
, which is derived from the theroetical rotation curve for the exponential disk(Chun 1978). These masses lie between
. 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.