• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.291-292
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• 2012

We select infrared-luminous galaxies by cross-matching the SDSS spectroscopic sample of galaxies with the WISE all-sky survey catalog. Based on photometric data points covering from SDSS u-band to WISE $22{\mu}m$, their spectral energy distributions (SEDs) are separated into AGN, elliptical, spiral, and irregular galaxy components. The derived luminosities of spiral galaxy and AGN are well correlated with $H{\alpha}$ and [OIII] line luminosities, respectively. Most galaxies are dominated by young stellar populations even for optical AGNs, but at least 10% of optical non-AGNs appear to harbor buried AGNs. The AGN contribution increases dramatically with the total luminosity. These results show that the SED decomposition is successful and is useful to understand the true nature of dusty galaxies.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.141-144
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• 2012

We present the results of Spectral Energy Distribution (SED) fitting of far-infrared galaxies detected in the AKARI Deep Field-South (ADF-S) Survey and discuss their physical properties. Additionally, we perform a comparison between photometric redshifts estimated using only optical and both optical and infrared data. We conclude that our sample consists mostly of nearby galaxies rich in dust and young stars. We observe an improvement in the estimation of photometric redshifts when the IR data are included, comparing to a standard approach based mainly on the optical to UV photometry.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.231-234
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• 2012

We present preliminary results of supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) seen by AKARI as well as Spitzer. By examining the AKARI LMC survey and the Spitzer data, we have searched for IR counterparts to 45 known SNRs in the LMC and could identify 28 SNRs with associated IR emission. 13 SNRs among them are newly detected in IR bands. For the entire IR SNRs, we make a catalog containing general information and the AKARI and/or Spitzer fluxes. Using the catalog, their IR colors and the possible correlation of the IR fluxes with the X-ray fluxes are examined. For some interesting SNRs, we have performed NIR spectroscopy with AKARI. An aromatic feature at $3.3{\mu}m$ can be identified in LMC SNR N49. We investigate the characteristics of the IR features and discuss the PAH mission mechanism in SNRs.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.105-109
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• 2012

The current status of the AKARI-FIS Point Source Catalogue is reported. The first version of the Bright Source Catalogue has been in public since March 2010 and used extensively in the various fields in astronomy. The second version of the Bright Source Catalogue and the first version of the Faint Source Catalogue are currently under development. The revised Bright Source Catalogue is expected to have improved completeness, reliability, and accuracy compared to the current version. The Faint Source Catalogue will have a scan-density dependent detection limit and will enable much deeper exploration of the sky especially in the high-ecliptic latitude regions. Both catalogues will be available in a year time scale.

• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.135-140
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• 2005

This paper summarizes the recent progress made by our group at Seoul National University on studies of the evolution and formation of distant galaxies. Various research projects are currently underway, which include: (i) the number density of distant early-type galaxies (z < 1); (ii) the optical-NIR color gradient of nearby early-type galaxies; (iii) J - K-selected Extremely Red Objects (EROs) in field (CDF-S) and the cluster environment; and (iv) the Lyman-break galaxies in the Spitzer First Look Survey (FLS) field. These works will constrain the mass evolution and the star formation history of galaxies in different environments, and the results will serve as useful contraints on galaxy formation models.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.275-279
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• 2017

The AKARI Deep Field South (ADF-S) is a large extragalactic survey field that is covered by multiple instruments, from optical to far-IR and radio. I summarise recent results in this and related fields prompted by the release of the Herschel far-IR/submm images, including studies of cold dust in nearby galaxies, the identification of strongly lensed distant galaxies, and the use of colour selection to find candidate very high redshift sources. I conclude that the potential for significant new results from the ADF-S is very great. The addition of new wavelength bands in the future, eg. from Euclid, SKA, ALMA and elsewhere, will boost the importance of this field still further.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.1
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• pp.64-73
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• 2015

Recent emergence of spatial big data attracts the attention of various research groups. This paper analyzes the research trend on spatial big data by text mining the related Scopus DB. We apply topic model and network analysis to the extracted abstracts of articles related to spatial big data. It was observed that optics, astronomy, and computer science are the major areas of spatial big data analysis. The major topics discovered from the articles are related to mobile/cloud/smart service of spatial big data in urban setting. Trends of discovered topics are provided over periods along with the results of topic network. We expect that uncovered areas of spatial big data research can be further explored.

• Journal for History of Mathematics
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• v.32 no.6
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• pp.271-279
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• 2019

Pierre-Simon de Laplace(1749-1827) is considered one of the most influential scientists in history. He was known to his contemporaries as the Newton of France, and a scientific sage valued for his magisterial syntheses of scientific works through the 18th century. Laplace was a determined mathematician, astronomer, writer, philosopher, and educator. In this paper, we take a survey of his achievements in the areas of astronomy and mathematical statistics, along with his scientific philosophy, the universal determinism.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.47.2-47.2
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• 2016

We introduce a magnetic field survey of the Gould Belt clouds using the James Clerk Maxwell Telescope (JCMT) POL-2: B-fields In STar-forming Region Observations (BISTRO). POL-2 with SCUBA-2 on JCMT is a unique facility, as it is the only facility world-wide that can map the magnetic field within cold dense cores and filaments on scales of ~1000 AU in nearby star-forming regions, such as Taurus and Ophiuchus. It can provide a link between the B-field measured on arc-minute scales by Planck and BLASTPOL and measurements made on arc-second scales by interferometers such as CARMA, SMA, and ALMA. BISTRO was awarded 224 hours toward 16 fields for the next 3 years and started to take data in the 2016A semester.

• Journal of The Korean Astronomical Society
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• v.38 no.4
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• pp.385-414
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• 2005

We have searched for infrared emission from supernova remnants (SNRs) included in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) field. At the positions of 100 known SNRs, we made 3.6, 4.5, 5.8, and $8.0{\mu}m$ band images covering the radio continuum emitting area of each remnant. In-depth examinations of four band images based on the radio continuum images of SNRs result in the identification of sixteen infrared SNRs in the GLIMPSE field. Eight SNRs show distinct infrared emission in nearly all the four bands, and the other eight SNRs are visible in more than one band. We present four band images for all identified SNRs, and RGB-color images for the first eight SNRs. These images are the first high resolution (<2') images with comparative resolution of the radio continuum for SNRs detected in the mid-infrared region. The images typically show filamentary emission along the radio enhanced SNR boundaries. Most SNRs are well identified in the 4.5 and $5.8{\mu}m$ bands. We give a brief description of the infrared features of the identified SNRs.