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
제39권 제1호 (2006년 3월) 4건
1.
2006.03
구독 인증기관 무료, 개인회원 유료
We present the results of a highly sensitive (~10 mK rms) survey toward the central parts of 22 barred spiral galaxies in 12CO(1-0) line using the NRAO 12m telescope at Kitt Peak. Seven of the target galaxies were detected in CO; NGC 3686 has been detected with CO for the first time. We estimated central CO fluxes of 50~1000 Jy km s-1 and molecular gas masses of 107~108 M⊙ for those galaxies.
4,000원
2.
2006.03
구독 인증기관 무료, 개인회원 유료
In an attempt to investigate star formation activity and statistical properties of clumps of high Galactic latitude clouds (HLCs), we mapped the Polaris Flare region, PF121.3+25.5, in 12CO and 13CO J = 1 - 0 using SRAO 6-m telescope and also observed its 12 13CO peak positions in CS J = 2 - 1 with TRAO 14-m telescope. 13CO integrated intensity map shows clearly its clumpy structure and the locations of clumps well agree with 12CO morphology. CS line is not detected toward the 12 13CO peak positions, so we can conclude there are no dense (~ 104 cm-3) in this region. We decomposed 105 clumps from 13CO map using GAUSSCLUMPS algorithm. The mass of clumps ranges from 7.8 M⊙ to 7.4x10-2 with a total mass of 66.4⊙ The mass spectrum follows a power law, dN/dM ∝ M-α with a power index of α =1.91 ± 0.13. The virial masses of clumps are in the range of 10 ~ 100 and so these clumps are considered to be gravitationally unbound.
4,000원
3.
2006.03
구독 인증기관 무료, 개인회원 유료
We carried out CO survey toward IR-excess clouds using SRAO 6-m telescope in search of molecular H2. These clouds, which show far-infrared excess over what is expected from HI column density, are considered to be candidates of molecular clouds. In order to find new high Galactic latitude clouds, we made mapping observations for 14 IR-excess clouds selected from Reach et al.(1998) in 12CO J = 1 - 0 line, supplementing the similar survey in southern hemisphere (Onishi et al. 2001). 12CO emission is detected from three IR-excess clouds among 14 objects. Three newly detected clouds exhibit somewhat clumpy morphology and column densities amount to ~ 1021 cm-2. One of three clouds, DIR120-28, show discrepancy between IR-excess center and CO emission center. It seems that IR-excess may not be an effective tracer of molecular gas. Instead, optical depth(τ) excess, i.e., IR-excess corrected for temperature dependence, may be more effective tracer of molecular clouds, since, by combining statistics from both hemispheres, we found that the detection rate is higher for IR-excess clouds with lower dust temperature.
4,000원
4.
2006.03
구독 인증기관 무료, 개인회원 유료
We completed four color light curves of the near-contact binary CN And during three nights from September to December 2004 using the 61-cm reflector and BV RI filters at Sobaeksan Observatory. We determined four new times of minimum light (two timings for primary eclipse, two for secondary). Newly obtained BV RI light curves and the radial velocity curves from Rucinski et a1. (2000) were simultaneously analyzed to derive the system parameters of CN And. We used the semi-detached mode 4 of the 2003-version of the Wilson-Devinney binary model, and interpreted the asymmetry of the light curve by introducing two spots; a cool spot on the primary component and a hot spot on the secondary component. New photometric parameters are not much different from those of Cicek et a1. (2005), and it is considered that the system is in the era of broken contact. From the orbital period study with all available timings including our data, we found a continous period decrease with a rate of Pobs = - -1.82 x 10-7 d yr-1 that can be explained with two possible mechanisms. We think the most likely cause of the period decrease is a thermal mass transfer from the primary to the secondary component, rather than angular momentum loss due to a magnetic stellar wind.
4,000원
