간행물
천문학회지 KCI 등재 SCOPUS Journal of The Korean Astronomical Society
- 발행기관 한국천문학회
- 자료유형 학술지
- 간기 반년간
- ISSN 1225-4614 (Print)2288-890X (Online)
- 수록기간 1968 ~ 2024
- 주제분류 자연과학 > 천문학 자연과학 분류의 다른 간행물
- 십진분류KDC 440DDC 520
권호리스트/논문검색
제36권 제4호 (2003년 12월) 3건
1.
2003.12
구독 인증기관 무료, 개인회원 유료
We have conducted a V-band CCD surface photometry of 68 disk galaxies to analyze the bulge morphology of nearby spirals. We classify bulges into four types according to their ellipticities and the misalignments between the major axis of the bulge and those of the disk and the bar: spherical, oblate, pseudo triaxial, and triaxial. We found that one third of the bulges are triaxial and they are preponderant in barred galaxies. The presence of the triaxial bulges in a significant fraction of unbarred galaxies as well as in barred galaxies might support the secular evolution hypothesis which postulates that the bar driven mass inflow leads to the formation of triaxial bulges and the destruction of bars when sufficient mass is accumulated in the central regions.
4,000원
2.
2003.12
구독 인증기관 무료, 개인회원 유료
We present results of a H13CN J=1-0 mapping survey of molecular clouds toward the Galactic Center (GC) region of -1.6° ≤ l ≤ 2° and -0.23° ≤ b ≤ 0.30° with 2' grid resolution. The H13CN emissions show similar distribution and velocity structures to those of the H12CN emissions, but are found to better trace the feature saturated with H12CN (1-0). The bright components among multi-components of H12CN line profiles usually appear in the H13CN line while most of the dynamically forbidden, weak H12CN components are seldom detected in the H13CN line. We also present results of other complementary observations in 12CO (J=1-0) and 13CO (J=1-0) lines to estimate physical quantities of the GC clouds, such as fractional abundance of HCN isotopes and mass of the GC cloud complexes. We confirm that the GC has very rich chemistry. The overall fractional abundance of H12CN and H13CN relative to H2 in the GC region is found to be significantly higher than those of any other regions, such as star forming region and dark cloud. Especially cloud complexes nearer to the GC tend to have various higher abundance of HCN. Total mass of the HCN molecular clouds within |l|≤ 6° is estimated to be ~2 ×10 7 M⊙ using the abundances of HCN isotopes, which is fairly consistent with previous other estimates. Masses of four main complexes in the GC range from a few 10 5 to ~ 10 7 M⊙ All the HCN spectra with multi-components for the four main cloud complexes were investigated to compare the line widths of the complexes. The largest mode (45 km s-1) of the FWHM distributions among the complexes is in the Clump 2. The value of the mode tends to be smaller at the farther complexes from the GC.
4,300원
3.
2003.12
구독 인증기관·개인회원 무료
The first sentence in the second paragraph of INTRODUCTION, 'The first discovery of a galaxy beyond z=5 was reported by Weymann et al. (1998); HDF 4-470.3 at z=5.60.' should be read as 'The first discovery of a galaxy beyond z=5 was reported by Dey et al. (1998); 0140+326 RD1 at z=5.34'. The authors sincerely regret this error.
