• Journal of Astronomy and Space Sciences
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• v.35 no.1
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• pp.19-30
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• 2018

The analysis of the high-resolution spectra of 31 Magellanic Clouds Cepheid variables enabled the identification of thorium lines. The abundances of thorium were found with spectrum synthesis method. The calculated thorium abundances exhibit correlations with the abundances of other chemical elements and atmospheric parameters of the program stars. These correlations are similar for both Clouds. The correlations of iron abundances of thorium, europium, neodymium, and yttrium relative to the pulsational periods are different in the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), namely the correlations are negative for LMC and positive or close to zero for SMC. One of the possible explanations can be the higher activity of nucleosynthesis in SMC with respect to LMC in the recent several hundred million years.

• The Bulletin of The Korean Astronomical Society
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• v.19
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• pp.29.1-29.1
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• 1994

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.223-224
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• 2012

Understanding the birth and evolution of galaxies, and the history of star formation in them, is one of the most important problems in astronomy. Using the data from the AKARI IRC survey of the Large Magellanic Cloud at 3.2, 7, 11, 15, and $24{\mu}m$, we have constructed a multi-wavelength catalog containing data from the cross-correlation with a number of other databases at different wavelengths. We present the first approach with a Support Vector Machine (SVM)-based method to separate different classes of stars in LMC in the color-color and color-magnitude diagrams.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.95-95
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• 1996

We present the recent results of an HI aperture synthesis mosaic of the Large Magellanic Cloud(LMC), made by combining data from 1344 separate pointing centers using the Australia Telescope Compact Array(ATCA). The resolution of the mosaiced images is 1'.0 (15 pc, using a distance to the LMC of 50 kpc). In contrast with its appearance at other wavelengths, the LMC is remarkably symmetric in HI on the largest scales, with the bulk of the HI residing in a disk of diameter 7.3 kpc. Outer spiral structure is clearly seen, though the features appear due to differential rotation, therefore transient in nature. A good correlation is seen between the supershells previously identified in Halpha (e.g. Meaburn 1980) and HI structures.

• Journal of the Korean earth science society
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• v.35 no.5
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• pp.362-374
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• 2014

This study investigated the initial mass function (IMF) and star formation history of high-mass stars in the Small Magellanic Cloud (SMC) using a population synthesis technique. We used the photometric survey catalog of Lee (2013) as the observable quantities and compare them with those of synthetic populations based on Bayesian inference. For the IMF slope (${\Gamma}$) range of -1.1 to -3.5 with steps of 0.1, five types of star formation models were tested: 1) continuous; 2) single burst at 10 Myr; 3) single burst at 60 Myr; 4) double bursts at those epochs; and 5) a complex hybrid model. In this study, a total of 125 models were tested. Based on the model calculations, it was found that the continuous model could simulate the high-mass stars of the SMC and that its IMF slope was -1.6 which is slightly steeper than Salpeter's IMF, i.e., ${\Gamma}=-1.35$.

• Journal of The Korean Astronomical Society
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• v.38 no.3
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• pp.365-370
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• 2005

We have made a multi-wavelength study of the X-ray bright giant shell complex 30 Doradus in the Large Magellanic Cloud (LMC). This is the one of the largest H II complexes in the Local Group. The Australia Telescope Compact Array (ATCA) and the Parkes 64-m single dish observations reveal that the distribution and internal motions of H I gas show the effects of fast stellar winds and supernova blasts. The hot emitting gas within the 30 Doradus complex and the entire giant H II complex are encompassed by an expanding H I shell. We investigate the dynamical age of this H I shell and compare to the age of starbursts occurred in the 30 Doradus nebula using the radiative transfer model and the infrared properties.

• Journal of the Korean earth science society
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• v.34 no.5
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• pp.415-427
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• 2013

We performed a BVR photometric survey for the entire Small Magellanic Cloud (~26 deg 2 ) with a mosaic system, Wide Field Imager (WFI), covering three seasons: September and October 2001 and November 2002. Through the usual data reduction procedures, we present ~0.73 million catalogue stars brighter than 19 magnitude in B amongst a total of ~1.3 million and compare them with published astrometry and photometry results. We found that the average differences between our and the published data are ~0.7 arcsec in astrometry and 0.065, 0.054, and 0.163 in B, V, and R, respectively, in photometry. In addition, using the 2dF spectroscopic data from Evans et al. (2004), we determined the color excesses in (B-V) and (V-R) to be $0.086{\pm}0.156$, and $0.065{\pm}0.112$, respectively, while for the distance modulus, we obtained $18.55{\pm}1.05$.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.31.1-31.1
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• 2011

We present wide-field near-IR imaging polarimetry of 30 Doradus in the Large Magellanic Cloud, using the InfraRed Survey Facility (IRSF). We obtained polarimetry data in J, H, and Ks bands using the JHKs-simultaneous imaging polarimeter SIRPOL. Since many Galactic field stars along the line-of-sight to the Large Magellanic Cloud are contaminated in our data, we developed methods to identify the foreground sources using the proper motion data. We investigated polarimetric properties between the Galactic foreground stars and the stars in the LMC.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.93-94
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• 1996

The Galaxy and the Large and Small Magellanic Clouds (LMC and SMC respectively) form a triple system of mutually interacting galaxies. We have carried out a set of N-body simulations on the gravitational interaction of the SMC with the Galaxy and the LMC in order to model prominent features such as the Magellanic Stream, the inter-Cloud Bridge, and the large depth of the SMC which are thought to be products of the tidal interactions among the members of this system.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.95.1-95.1
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• 2007