Search

The study of the Large Magellanic Cloud (LMC) is important to understand the formation process of massive stellar clusters. N159 is one of the most active cluster forming regions in the LMC. Bolatto et al. [2] observed sub-mm CO and C i lines in this region and found CO(J=4–3) the emission peak at N159W. This observation didn’t have enough resolution to reveal the high temperature molecular cloud structure. So we observe with the NANTEN2 telescope to improve the image resolution.

tetsu@astro1.sci.hokudai.ac.jp 2 Department of Astrophysics, Nagoya University, Japan 3 National Astronomical Observatory of Japan, Japan 4 Research Center for the Early Universe and Department of Physics, University of Tokyo, Japan 5 National Radio Astronomy Observatory, USA 6 Department of Astronomy, MC 221, University of Illinois, USA 7 Australia Telescope National Facility, CSIRO, Australia 8 Radioastronomisches Institut der Universitat Bonn, Germany 9 Center for Supercomputing and Astrophysics, Swinburne University of Technology, Germany 10 School of Physics, University of Western Australia, Australia 11 Solar-Terrestrial Environment Laboratory, Nagoya University, Japan 12 Departament de Astronomia, Universidad de Chile, Chile 13 Hartebeesthoek Radio Astronomy Observatory, South Africa 14 Onsala Space Observatory, Sweden 15 European Southern Observatory 16 Astronomy & Space Science Department, Sejong University, Korea

We review observational results concerning star formation and dense molecular clouds, the interstellar medium most relevant to star-formation process, as well as future prospects.

We present new observational data of 13CO J= 1−0 emission in nearby molecular cloud complexes in Taurus, Ophiuchus, and Orion, and compare star formation efficiencies in the three regions. The 13CO data have been obtained with the 4m millimeter telescope at Nagoya equipped with a SIS receiver having receiver temperature of 23 K in double side band. The molecular distribution is often characterized by highly filamentary, continuous distribution, rather than well defined clumps. Active star formation is taking place almost exclusively in the densest regions in the molecular distributions. The filamentary distributions often show velocity gradients perpendicular to their elongation, suggesting that they are spinning around their major axes. Roles of photoionization and the spinning motion on formation of stars and clouds are discussed as a step toward understanding the mechanism regulating star formation efficiencies.

We have been surveying dense molecular cores in Ophiuchus region including p Oph, L234, and L43 with the 4m radio telescope at Nagoya University since 1985. We have already mapped ~18°x12- area with 2´ or 4´ grid spacing in 13CO(J=l−0) spectra. We have identified~50 dense cores (we call”13CO cores“). Typical mass, density, and size of the13CO cores are~20 M⨀,⨀3x103 cm-3, and~0.3 pc, respectively (Nozawa et al. 1990). We also surveyed molecular outflows in 12CO (J=l−0) spectra toward 13 IRAS point sources associated with 13CO cores in Ophiuchus. As a result of the survey, we have found 5 molecular outflows in the filamentary dark clouds and 5 regions exhibiting high velocity wings in the p Oph main body

We mapped 5 dense cores in the Cepheus molecular cloud in the optically thin C180 (J = 1 – 0) line using the 45-m telescope at Nobeyama and derived density profiles around those cores assuming spherical symmetry. Cloud cores are selected from the 13CO ( = 1 – 0) map obtained through the unbiased survey program with the 4-m telescope at Nagoya university

We present preliminary results of a survey of bright-rimmed clouds associated with IRAS point sources