• Title/Summary/Keyword: OB associations

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Associations of PSI, WCC, and DSOM in Mothers of Elementary School Children (초등학생 어머니의 양육스트레스, 대처방식 및 한방진단시스템과의 연관성 연구)

  • Lim, Jung-Hwa;Lee, In-Sun;Jung, In-Chul;Hwang, Bo-Min;Jeong, Min-Jeong
    • Journal of Oriental Neuropsychiatry
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    • v.21 no.4
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    • pp.99-112
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    • 2010
  • Objectives : This study was to investigate the associations of Parent Stress Index(PS]). Way of Coping Checklist(WCC). and Diagnostic System of Oriental Medicine(DSOM) in mothers of elementary school children. Methods: In the study. K-PSI-SF. WCC. and DSOM were carried out on 202 mothers of O Oelementary school children during June. 2010. Cross tabulation analysis was used to verify the association of PSI. WCC and DSOM. Results: 1. The most common pathogenic factor was Dampness(濕) in total subjects. 2. The score of problem-focused coping methods showed significant difference in PSI grades. 3. The zp and sc10 of Qi deficiency(氣虛), Blood deficiency(血虛), Qi-Stagnation(氣滯), Insufficiency of Yang(陽虛), Heat(熱), Dampness(濕), Dryness(燥), Liver(肝), Heart(心), and Kidney(腎) showed significant difference in PSI grades. 4. The score of total PSI and PSI subscale had negative correlations with problem-focused coping methods 5. The score of total PSI had positive correlations with Qi-Stagnation (氣滯), Dampness(濕), Dryness(燥), Heart(心), and Kidney(腎) in total subjects. Conclusions : This study provides insights on associations of parenting stress coping methods and diagnostic system in Oriental Medicine. Furthermore, the study shows positive correlations among Qi-Stagnation (氣滯), Dampness(濕), Dryness(燥), Heart(心), Kidney(腎) and PSI, and negative correlations between PSI and Problem-focused coping methods, all with statistical significance.

STELLAR CONTENTS AND GLOBULAR CLUSTER CANDIDATES IN THE SCULPTOR GROUP GALAXY NGC 300

  • KIM SANG CHUL;SUNG HWANKYUNG;LEE MYUNG GYOON
    • Journal of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.9-28
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    • 2002
  • We present UBVI CCD photometry of the stellar contents and globular cluster(GC) candidates in the spiral galaxy NGC 300 in the Sculptor group. Color-magnitude diagrams for 18 OB associations having more than 30 member stars are presented. The slope of the initial mass function for the bright stars in NGC 300 is estimated to be ${\Gamma}= -2.6{\pm} 0.3$. Assuming the distance to NGC 300 of (m - M)o = 26.53 $\pm$ 0.07, the mean absolute magnitude of three brightest blue stars is obtained to be < $M_v^{BSG}$ (3) > = -8.95 mag. We have performed search for GCs in NGC 300 and have found 17 GC candidates in this galaxy. Some characteristics of these GC candidates are discussed.

PMS EVOLUTION MODEL GRIDS AND THE INITIAL MASS FUNCTION

  • PARK BYEONG-GON;SUNG HWANKYUNG;KANG YONG HEE
    • Journal of The Korean Astronomical Society
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    • v.35 no.4
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    • pp.197-208
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    • 2002
  • Five contemporary pre-main sequence (PMS) evolution model grids are compared with the photo-metric data for a nearly complete sample of low-mass members in NGC 2264. From amongst the grids compared, the models of Baraffe et al. (1998) prove to be the most reliable in mass-age distribution. To overcome the limited mass range of the models of Baraffe et al. we derived a simple transformation relation between the mass of a PMS star from Swenson et al. (1994) and that from Baraffe et al., and applied it to the PMS stars in NGC 2264 and the Orion nebula cluster (ONC). The resulting initial mass function (IMF) of the ONC shows that the previous interpretation of the IMF is not a real feature, but an artifact caused by the evolution models adopted. The IMFs of both clusters are in a good agreement with the IMF of the field stars in the solar neighborhood. This result supports the idea proposed by Lada, Strom, & Myers (1993) that the field stars originate from the stars that are formed in clusters and spread out as a result of dynamical dissociation. Nevertheless, the IMFs of OB associations and young open clusters show diverse behavior. For the low-mass regime, the current observations suffer from difficulties in membership assignment and sample incompleteness. From this, we conclude that a more thorough study of young open clusters is necessary in order to make any definite conclusions on the existence of a universal IMF.

A High-Velocity Cloud Impact Forming a Supershell in the Milky Way

  • Park, Geumsook;Koo, Bon-Chul;Kang, Ji-hyun;Gibson, Steven J.;Peek, J.E.G.;Douglas, Kevin A.;Korpela, Eric J.;Heiles, Carl E.
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.39.1-39.1
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    • 2016
  • We report the discovery of a kiloparsec-size supershell in the outskirts of the Milky Way with the compact high-velocity cloud, HVC 040+01-282 (hereafter, CHVC040), at its geometrical center using the "Inner-Galaxy Arecibo L-band Feed Array" HI 21 cm survey data. Supershells are large gaseous shells, which could be produced by one of most energetic activities with an explosion energy more than $3{\times}1052erg$. The most promising origin is the explosion of multiple supernovae in OB associations, or alternatively, the impact of HVCs falling into the Galactic disk. We found the association between CHVC040 and the Galactic supershell by analysis of their morphological and physical properties. Our results imply that some compact HVCs can survive their trip through the Galactic halo and inject energy and momentum into the Milky Way disk.

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Core formation in different environments: Planck Galactic Cold Clumps (PGCCs) in the λ Orionis cloud, Orion A and Orion B clouds

  • Yi, HeeWeon;Lee, Jeong-Eun;Liu, Tie;Kim, Kee-Tae;Wu, Yuefang
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.37.4-38
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    • 2016
  • Based on the $850{\mu}m$ dust continuum data from James Clerk Maxwell Telescope (JCMT)/SCUBA-2, we compare overall properties of Planck Galactic Cold Clumps (PGCCs) in the ${\lambda}$ Orionis cloud with PGCCs in other molecular clouds, Orion A and Orion B. The Orion A and Orion B clouds are well known active star-forming region, while, ${\lambda}$ Orionis cloud has a different environment associating with prominent OB associations and a giant H II region. PGCCs in the ${\lambda}$ Orionis cloud have higher dust temperatures (Td~16.08 K) and lower values of dust emissivity (${\beta}{\sim}1.65$) than Orion A and Orion B clouds. In addition, we found the lowest detection rate (16 %, 8 out of 50) of PGCCs at $850{\mu}m$ in the ${\lambda}$ Orionis cloud while among three regions; Orion A and Orion B clouds show much higher detection rates of ~ 76 % (23 out of 30) and 56 % (9 out of 16), respectively. The detected 8 PGCCs in the ${\lambda}$ Orionis cloud have substructures and we identified 15 cores. The cores also show much lower median values of size (~0.08 pc), column density (~ ), number density (~ ), and mass (~ ) compared with other cores in the Orion A and Orion B clouds. These core properties in the ${\lambda}$ Orionis cloud can be attributed to the compression and external heating by the nearby H II region, which may prevent the PGCCs from forming gravitationally bound structures and eventually disperse them. These results well present the negative stellar feedback to core formation.

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Far-ultraviolet Observations of the Taurus-Perseus-Auriga Complex

  • Lim, Tae-Ho;Min, Kyoung-Wook;Seon, Kwang-Il
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.98.2-98.2
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    • 2012
  • We firstly present the unified Far-UV continuum map of the Taurus-Auriga-Perseus (TPA) complex, one of the largest local associations of dark cloud located in (l, b)=([154,180], [-28, -2]), by merging both FIMS and GALEX. The FUV continuum map shows that dust extinction correlate well with the FUV around the complex. It shows strong absorption in FUV toward the dense Taurus cloud while it does not in California cloud. It turned out that it is related to the relative location of each cloud and Perseus OB2 association. We also present some results of dust scattering simulation based on Monte Carlo Radiative Transfer technique (MCRT). Through this dust scattering simulation, we have derived the scattering parameter for this region, albedo(a)=$0.42^{+0.05}{_{-0.05}}$, asymmetry factor(g)=$0.47^{+0.11}{_{-0.27}}$. The optical parameters we obtained seem reasonable compared to the theoretical model values ~0.40 and ~0.65 for the albedo and the phase function though the phase function is rather small. Using the result of simulation, we figured out the geometries of each cloud in the complex region, especially their distances and thicknesses. Our predictions from the results are in good agreement with the previous studies related to the TPA complex. For example, the Taurus cloud is within ~200pc from the Sun and the Perseus seems to be multi-layered, at least two. The California cloud is more distant than the other cloud on average at ~350 pc and Auriga cloud seems to be between the Taurus cloud and the eastern end of the California cloud. We figured out that across the TPA complex region, there might be some correlation between the LSR velocity and the distance to each cloud in the complex.

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