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한국천문학회지

1968년 ~ 2024년까지 1,211 건한국천문학회지를 격월간 확인하실 수 있습니다.

  • The Korean Astronomical Society (The Korean Astronomical Society)
  • 계간 (Quarterly)
  • ISSN : 1225-4614 (ISSN : 1225-4614)
  • DB구축현황 : 1,211건 (DB Construction : 1,211 Articles)
안내사항
총 게시글 1,211 페이지 50/122
491
  • ZHOU Xu
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.2
  • pp.203-206
  • 2005
  • 원문 바로보기
The large field multi-color CCD sky survey program based on the 60/90 Schmidt telescope of NAOC has been processed in cooperation among many observatories and universities of Asian countries. The observation and scientific results are reviewed.
492
  • Lee, Ho-Gyu
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.4
  • pp.385-414
  • 2005
  • 원문 바로보기
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 <TEX>$8.0{\mu}m$</TEX> 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 <TEX>$5.8{\mu}m$</TEX> bands. We give a brief description of the infrared features of the identified SNRs.
493
  • YUAN CHI
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.2
  • pp.197-201
  • 2005
  • 원문 바로보기
It is well known that a rotating bar potential can transport angular momentum to the disk and hence cause the evolution of the disk. Such a process is particularly important in disk galaxies since it can result in fuelling AGNs and starburst ring activities. In this paper, we will present the numerical simulations to show how this mechanism works. The problem, however, is quite complicated. We classify our simulations according to the type of Lindbald resonances and try to single out the individual roles they play in the disk evolution. Among many interesting results, we emphasize the identification of the origin of the starburst rings and the dense circumnuclear molecular disks to the instability of the disk. Unlike most of the other simulations, the self-gravitation of the disk is emphasized in this study.
494
  • WANG YUN-CHING
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.2
  • pp.299-302
  • 2005
  • 원문 바로보기
Sprites, elves and blue jets are collectively denominated as the upper atmospheric transient luminous events (TLEs). They are recently discovered optical flashes between active thunderstorms and the ionosphere. In this report, a brief introduction to the most important characteristics of TLEs is given. Since 2001, scientists from the National Cheng Kung University have been performing yearly summer campaigns from various locations in Taiwan. The main achievements of their yearly campaign are presented.
495
  • KANG MEEJOO
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.2
  • pp.33-41
  • 2005
  • 원문 바로보기
We have conducted observations toward the molecular cloud associated with the H II region Sh 156 in <TEX>$^{13}CO$</TEX>(J = 1-0), <TEX>$C^{18}O$</TEX>(J = 1-0), and CS(J = 2 -1) using the TRAO 14 m telescope. Combining with existing <TEX>$^{12}CO$</TEX>(J = 1- 0) data of the Outer Galaxy Survey, we delineated the physical properties of the cloud. We found that there is a significant sign of interaction between the H II region and the molecular gas. We estimated the masses of the molecular cloud, using three different techniques; the most plausible mass is estimated to be <TEX>$1.37 {\times} 10^5 M_{\bigodot}$</TEX>, using a conversion factor of <TEX>$X = 1.9 {\times} 10^{20}\;cm^{-2} (K\;km\;s^{-1})^{-1}$</TEX>, and this is similar to virial mass estimate. This implies that the cloud is gravitationally bound and in virial equilibrium even though it is closely associated with the H II region. In addition to existing outflow, we found several MSX and IRAS point sources associated with dense core regions. Thus, more star forming activities other than the existing H II region are also going on in this region.
496
  • Kim Sang-Chul
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.4
  • pp.429-435
  • 2005
  • 원문 바로보기
We present BV CCD photometry for the open clusters Czernik 24 and Czernik 27. These clusters have never been studied before, and we provide, for the first time, the cluster parameters; reddening, distance, metallicity and age. Czernik 24 is an old open cluster with age <TEX>$1.8{\pm}0.2Gyr$</TEX>, metallicity <TEX>$[Fe/H]=-0.41{\pm}0.15dex$</TEX>, distance modulus <TEX>$(m-M)_0=13.1{\pm}0.3mag$</TEX> (<TEX>$d=4.1{\pm}0.5kpc$</TEX>), and reddening <TEX>$E(B-V)=0.54{\pm}0.12mag$</TEX>. The parameters for Czernik 27 are estimated to be <TEX>$age=0.63{\pm}0.07Gyr$</TEX>, <TEX>$[Fe/H]=-0.02{\pm}0.10dex$</TEX>, <TEX>$(m-M)_0=13.8{\pm}0.2mag$</TEX> (<TEX>$d=5.8{\pm}0.5kpc$</TEX>), and <TEX>$E(B-V)=0.15{\pm}0.05mag$</TEX>. The metallicity and distance values for Czernik 24 are consistent with the relation between the metallicity and the Galactocentric distance of other old open clusters. We find the metallicity gradient of 51 old open clusters including Czernik 24 to be <TEX>${\Delta}[Fe/H]/{\Delta}R_{gc}=-0.064 {\pm}0.009dex\;kpc^{-1}$</TEX>.
497
  • Kyeong, Jae-Mann
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.4
  • pp.415-422
  • 2005
  • 원문 바로보기
UBVIJHK photometry of the open cluster NGC 2194 are presented. Color-Magnitude diagrams of this cluster show well-defined main sequence and red giant clump. The main sequence also contains clear evidence of binary populations. Based on color-color diagrams, absolute magnitude of red giant clump, ZAMS fitting, and comparisons of observed color-magnitude diagrams with theoretical models, we derive following parameters for the cluster; reddening <TEX>$E(B-V)=0.44{\pm}0.04$</TEX>, age of log <TEX>$t{\sim}8.8$</TEX>, and finally distance of <TEX>$(m-M)_0=12.20{\pm}0.18$</TEX>.
498
  • FENG LONG-LONG
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.2
  • pp.129-133
  • 2005
  • 원문 바로보기
The temperature (T) and entropy (S) fields of baryonic gas, or intergalactic medium (IGM), in the ACDM cosmology are analyzed using simulation samples produced by a hybrid cosmological hydrodynamic/N-body code based on the weighted essentially non-oscillatory scheme. We demonstrate that, in the nonlinear regime, the dynamical similarity between the IGM and dark matter will be broken in the presence of strong shocks in the IGM. The heating and entropy production by the shocks breaks the IGM into multiple phases. The multiphase and non-Gaussianity of the IGM field would be helpful to account for the high-temperature and high-entropy gas observed in groups and clusters with low-temperature IGM observed by Ly<TEX>$\alpha$</TEX> forest lines and the intermittency observed by the spikes of quasi-stellar object's absorption spectrum.
499
  • YAO YONGQIANG
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.2
  • pp.335-336
  • 2005
  • 원문 바로보기
The working group for an infrared telescope(IRT) toward East Asian Observatory has been set up in EAMA6. This report declares the membership of IRT working group, reviews briefly the activities of promoting the IRT, and puts forward the future plan.
500
  • NISHIOKA HIROAKI
  • Journal of the Korean astronomical society = 천문학회지
  • 38, n.2
  • pp.175-178
  • 2005
  • 원문 바로보기
We show that next-generation galaxy surveys such as KAOS (the Kilo-Aperture Optical Spectro-graph)will constrain dark energy even if the baryon oscillations are missing from the monopole power spectrum and the bias is scale- and time-dependent KAOS will accurately measure the quadrupole power spectrum which gives the leading anisotropies in the power spectrum in redshift space due to peculiar velocities, the finger of God effect, as well as the Alcock-Paczynski effect. The combination of monopole and quadrupole power spectra powerfully breaks the degeneracy between the bias parameters and dark energy and, in the complete absence of baryon oscillations (<TEX>$\Omega$</TEX>b = 0), leads to a roughly <TEX>$500\%$</TEX> improvement in constraints on dark energy compared with the monopole spectrum alone. As a result, for KAOS the worst case with no oscillations has dark energy errors only mildly degraded relative to the ideal case, providing insurance on the robustness of KAOS constraints on dark energy. We show that nonlinear effects are crucial in correctly evaluating the quadrupole and significantly improving the constraints on dark energy when we allow for multi-parameter scale-dependent bias.