Nagayoshi OHASHI
Institute of Astronomy and Astrophysics,
Academia Sinica,
128, Sec. 2, Yen Geo Yuan Road,
Nankang, Taipei, Taiwan, R.O.C.
Tel: 886-2-33652020 x 730
Fax: 886-2-23677849
e-mail: ohashi@asiaa.sinica.edu.tw

Discovery of a new protostar!!
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Personal Education

Professional Experience

Research Interests
  • Star and planet formation; protostars, T Tauri stars, binaries, clusters, dense cores, protoplanetary disks, infall, outflow
  • Techniques for interferometers; receiver system, compensation for phase fluctuations, remote observation system

Refereed Papers
  1. N. Ohashi, A. Mizuno, K. Tatematsu, K. Sugitani, T. Kasuga, and Y. Fukui, 1989, A.J., 97, 458, "Interferometric Observations of M42 at 1.3 cm"
  2. K. Sugitani, Y. Fukui, A. Mizuno, and N. Ohashi, 1989, Ap.J.(Letters), 342, L87, "Star Formation in Bright-rimmed Globules: Evidence for Radiation-driven Implosion"
  3. K. Koyama, S. Takano, Y. Tawara, T. Matsumoto, K. Noguchi, Y. Fukui, T. Iwata, N. Ohashi, K. Tatematsu, N. Takahashi, T. Umemoto, K. W. Hodapp, J. Rayner, and K. Makishima, 1991, Ap.J., 377, 240, "An X-ray Pulsator in the Direction of Molecular Cloud MBM 12 (Lynds 1457)"
  4. N. Ohashi, R. Kawabe, M. Hayashi, and M. Ishiguro, 1991, A.J., 102, 2054, "Observations of 11 Protostellar Sources in Taurus with Nobeyama Millimeter Array: Growth of Circumstellar Disks"
  5. A. Nakamura, R. Kawabe, Y. Kitamura, M. Ishiguro, Y. Murata, and N. Ohashi, 1991, Ap.J.(Letters), 383, L81, "Aperture Synthesis CS(2-1) Observations of a Young Stellar Object GL490: Accretion Flow in Gas Disk"
  6. K. Akabane, S. Tsunekawa, M. Inoue, R. Kawabe, N. Ohashi, O. Kameya, M. Ishiguro, and Y. Sofue, 1992, Publ. Astron, Soc. Japan, 44, 421, "Millimeter-Wave Continuum around NGC 7538-IRS1, IRS2, and IRS3"
  7. K. Tatematsu, T. Umemoto, O. Kameya, N. Hirano, T. Hasegawa, M. Hayashi, T. Iwata, N. Kaifu, H. Mikami, Y. Murata, M. Nakano, T. Nakano, N. Ohashi, K. Sunada, H. Takaba, S. Yamamoto, 1993, Ap.J. 404, 643, "Molecular Cloud Cores in the Orion A Cloud. I. Nobeyama CS(1-0) Survey"
  8. M. F. Skrutskie, R. L. Snell, K. M. Strom, S. E. Strom, S. Edwards, Y. Fukui, A. Mizuno, M. Hayashi, and N. Ohashi, 1993, Ap.J., 409, 422, "Detection of A Gaseous Circumstellar Disk Associated with GG Tau"
  9. M. Hayashi, N. Ohashi, S. M. Miyama, 1993, Ap.J.(Letters), 418, L71, "A Dynamically Accreting Gas Disk around HL Tau"
  10. M. Hayashi, T. Hasegawa, N. Ohashi, and K. Sunada, 1994, Ap.J., 426, 234, "C18O (J=1-0) Survey of Protostellar Candidates Embedded in the Taurus Molecular Cloud"
  11. D. N. D. Lin, M. Hayashi, K. R. Bell, and N. Ohashi, 1994, Ap.J., 435, 821, "Is HL Tauri an FU Orionis System in Quiescence?"
  12. A. Mizuno, T. Onishi, M. Hayashi, N. Ohashi, K. Sunada, T. Hasegawa, and Y. Fukui, 1994, Nature, 368, 719 "Molecular cloud condensation as a tracer of low-mass star formation"
  13. T. Handa, S. Miyama, T. Yamashita, T. Omodaka, Y. Kitamura, M. Hayashi, T. Onishi, R. Snell, S. Strom, K. Strom, M. Skrutskie, S. Edward, N. Ohashi, K. Sunada, M. Saito, Y. Fukui, A. Mizuno, J.-I., Watanabe, and H. Kataza, 1995, Ap.J., 449, 894, "Detection of a Circumstellar Gas around DM Tauri: A Protoplanetary Disk around a Single Star?"
  14. H. Chen, J.-H. Zhao, and N. Ohashi, 1995, Ap.J.(Letters), 450, L71, "Dust Emission from L1641N: An Optically Thick Circumstellar Disk?"
  15. J. Yang, N. Ohashi, and Y. Fukui, 1995, Ap.J., 455, 175, "Interferometric Observations of the Circumstellar Molecular Structure around the Young Stellar Object in L1287"
  16. N. Ohashi, M. Hayashi, R. Kawabe, and M. Ishiguro, 1996, Ap.J., 466, 317, "The Nobeyama Millimeter Array Survey of Young Stellar Objects associated with the Taurus Molecular Cloud"
  17. N. Ohashi, M. Hayashi, P. T. P. Ho, M. Momose, and N. Hirano, 1996, Ap.J., 466, 957, "Possible Infall in the Gas Disk around L1551-IRS5"
  18. H. Chen, N. Ohashi, and T. Umemoto, 1996, A.J., 112, 717, "High Resolution Millimeter Imaging of L1641N: Multiple Cores with a Young Stellar Group"
  19. M. Momose, N. Ohashi, R. Kawabe, M. Hayashi, and T. Nakano, 1996, Ap.J., 470, 1001, "The Dispersing Cloud Core around T Tauri"
  20. M. Tamura, N. Ohashi, N. Hirano, Y. Itoh, & G. H. Moriarty-Schieven 1996, A.J., 112, 2076, "Interferometer Observations of Outflows from Low-Mass Protostars in Taurus"
  21. N. Ohashi, M. Hayashi, P. T. P. Ho, and M. Momose, 1997, Ap.J., 475, 211, "Interferometric Imaging of IRAS 04368+2557 in the L1527 Molecular Cloud Core: A Dynamically Infalling Envelope with Rotation"
  22. J. Yang, N. Ohashi, J. Yan, C. Liu, N. Kaifu, and H. Kimura, 1997, Ap.J., 475, 683, "Detection of Infalling Motion from the Circumstellar Disk Associated with the Exciting Source of HH111"
  23. N. Ohashi, M. Hayashi, P. T. P. Ho, M. Momose, M. Tamura, N. Hirano, and A. I. Sargent, 1997, Ap.J., 488, 317, "Rotation in the Protostellar Envelopes around IRAS 04169+2702 and IRAS 04365+2535: The Size Scale for Dynamical Collapse"
  24. Q. Zhang, P. T. P. Ho, and N. Ohashi, 1998, Ap.J., 494, 636, "Dynamical Collapse in W51 Massive Cores: CS(3-2) and CH3CN Observations"
  25. M. Momose, N. Ohashi, R. Kawabe, T. Nakano, and M. Hayashi, 1998, Ap.J., 504, 314, "Aperture Synthesis C18O(J=1-0) Observations of L1551 IRS5: Detailed Structure of the Infalling Envelope"
  26. N. Ohashi, S.-W. Lee, D. J. Wilner, and M. Hayashi, 1999, Ap.J.(Letter), 518, 41, "CCS Imaging of the Starless Core L1544: An Envelope with Infall and Rotation"
  27. Park, Y.-S., Panis, J.-F., Ohashi, N., Choi, M., Minh, Y. C. 2000, Ap.J., 542, 344, "Interferometric Observation of the L483 Molecular Core"
  28. Aikawa, Y., Ohashi, N., Inutsuka, S., Herbst, E., Takakuwa, S., 2001, Ap.J., 552, 639, "Molecular Evolution in Collapsing Prestellar Cores"
  29. Di Francesco, J., Myers, P. C., Wilner, D. J., Ohashi, N., Mardones, D., 2001, Ap.J., 562, 770, "Infall, Outflow, Rotation, and Turbulent Motions of Dense Gas within NGC 1333 IRAS 4"
  30. Takakuwa, S., Ohashi, N., Hirano, N., 2003, Ap.J., 590, 932, "Interaction between the Outflow and the Core in IRAM 04191+1522"
  31. Aikawa, Y., Ohashi, N., Herbst, E., 2003, ApJ, 593, 906, "Molecular Evolution in Collapsing Prestellar Cores. II. The Effect of Grain- Surface Reactions"
  32. Shinnaga, H., Ohashi, N., Lee, S.-W., Moriarty-Schieven, G., 2004, ApJ, 601, 962, "Physical Properties and Kinematic Structure of a Starless Core in Taurus Molecular Cloud"
  33. Takakuwa, S., Ohashi, N., Ho, P. T. P., Qi, C., Wilner, D. J., Zhang, Q., Bourke, T. L., Hirano, N., Choi, M., Yang, J., 2004, ApJL, 616, L15, "Submillimeter Array Observations of L1551 IRS5 in CS (J=7-6)"
  34. Su, Y.-N., Liu, S.-Y., Lim, J., Ohashi, N., Beuther, H., Zhang, Q., Sollins, P., Hunter, T., Sridharan, T. K., Zhao, J.-H., Ho, P. T. P., 2004, ApJL, 616, L39, "Search for Calibrators for the Submillimeter Array: 1. High-Mass Star Forming Regions"
  35. Qi, C., Ho, P. T. P., Wilner, D. J., Takakuwa, S., Hirano, N., Ohashi, N.,Bourke, T. L., Zhang, Q., Blake, G. A., Hogerheijde, M., Saito, M., Choi, M., Yang, J., 2004, ApJL, 616, L11, "Imaging the Disk around TW Hya with the Submillimeter Array"
  36. Beuther, H., Hunter, T. R., Zhang, Q., Sridharan, T. K., Zhao, J.-H., Sollins, P., Ho, P. T. P., Ohashi, N., Su, Y.-N., Lim, J., Liu, S.-Y., 2004, ApJL, 616, L31 "SMA outflow/disk studies in the massive star-forming region IRAS 18089- 1732"
  37. Matsushita, S., Sakamoto, K., Kuo, C.-Y., Hsieh, P.-Y., Trung, D.-V., Mao, R.-Q., Iono, D., Peck, A. B., Wiedner, M. C., Liu, S.-Y., Ohashi, N., Lim, J., 2004, ApJL, 616, L55, "SMA 12CO(J=3-2) Interferometric Observations of the Central Region of M51"
  38. Kuan, Y.-J., Huang, H.-C., Charnley, S. B., Hirano, N., Takakuwa, S., Wilner, D. J., Liu, S.-Y., Ohashi, N.i, Bourke, T. L., Qi, C., Zhang, Q., 2004, ApJL, 616, L27 "Organic Molecules in Low-Mass Protostellar Hot Cores: Submillimeter Imaging of IRAS 16293-2422"
  39. Sollins, P. K., Hunter, T. R., Battat, J., Beuther, H., Ho, P. T. P., Lim, J., Liu, S. Y., Ohashi, N., Sridharan, T. K., Su, Y. N., Zhao, J.-H., Zhang, Q. 2004, ApJL, 616, L35 "Mapping the Outflow from G5.89-0.39 in SiO J = 5-4"
  40. Young, K. H., Hunter, T. R., Wilner, D. J., Gurwell, M. A., Barrett, J. W., Blundell, R., Christensen, R., Fong, D., Hirano, N., Ho, P. T. P., Liu, S. Y., Lo, K. Y., Martin, R., Matsushita, S., Moran, J. M., Ohashi, N., Papa, D. C., Patel, N., Patt, F., Peck, A., Qi, C., Saito, M., Schinckel, A., Shinnaga, H., Sridharan, T. K., Takakuwa, S., Tong, C. E., Trung, D. V., 2004, ApJL, 616, L51, "Submillimeter Array Observations of CS J = 14-13 Emission from the Evolved Star IRC +10216"
  41. Lin, S.-Y., Ohashi, N., Lim, J., Ho, P. T. P., Fukagawa, M., Tamura, M., 2006, ApJ, 645, 1297L "Possible Molecular Spiral Arms in the Protoplanetary Disk of AB Aur"
  42. Chen, H.-R., Su, Y.-N., Liu, S.-Y., Hunter, T. R., Wilner, D. J., Zhang, Q., Lim, J., Ho, P. T. P., Ohashi, N., Hirano, N. 2006, ApJ, 654, L87, "650 GHz Continuum and C18O(6-5) Observations of G240.31+0.07 with the Submillimeter Array"
  43. Jorgensen, J. K., Bourke, T. L., Myers, P. C., Di Francesco, J., van Dishoeck, E. F., Lee, C.-F., Ohashi, N., Schoier, F. L., Takakuwa, S., Wilner, D. J., Qizhou, Z. 2007, ApJ, 659, 479, "PROSAC: A Submillimeter Array Survey of Low-Mass Protostars. I. Overview of Program: Envelopes, Disks, Outflows, and Hot Cores"
  44. Takakuwa, S., Ohashi, N., Bourke, T. L., Hirano, N., Ho, P. T. P., Jorgensen, J. K., Kuan, Y.-J., Myers, P. C., Wilner, D. J., Yeh, S. C. C., 2007, ApJ, 662, 431, "Arcsecond-Resolution Submillimeter HCN Imaging of the Binary Protostar IRAS 16293-2422"
  45. Manoj, P., Ho, P. T. P., Ohashi, N., Zhang, Q., Hasegawa, T., Chen, H.-R., Bhatt, H. C., Ashok, N. M. 2007, ApJ, 667, L187 "An Evolved Disk Surrounding the Massive Main-Sequence Star MWC 297?"
  46. Yeh, S. C. C., Hirano, N., Bourke, T. L., Ho, P. T. P., Lee, C.-F., Ohashi, N., Takakuwa, S. 2008, ApJ, 675, 454 "The CO Molecular Outflows of IRAS 16293-2422 Probed by the Submillimeter Array"
  47. Karr, J. L., Manoji, P., Ohashi, N. 2008, ApJ, submitted "Gum 48d: an evolved HII region with ongoing star formation"
  48. Takahashi, S., Saito, M., Ohashi, N., Kusakabe, N., Takakuwa, S., Shimajiri, Y., Tamura, M., Kawabe, R. 2008, ApJ, submitted "Millimeter- and Submillimeter-Wave Observations of the OMC-2/3 Region. III. An Extensive Survey for Molecular Outflows"
  49. Ohashi, N., Momose, M. 2008, ApJ, submitted "Submillimeter Observations of the Protoplanetary Disk around HD 142527: A Gas-Poor Dust Arc"

Books
  1. Myers, P. C., Evans, N. J., II, Ohashi, N. 2000 Protostars and Planets IV (Book - Tucson: University of Arizona Press; eds Mannings, V., Boss, A.P., Russell, S. S.), p. 217

Conference Contributions
  1. N. Ohashi, R. Kawabe, M. Hayashi, and M. Ishiguro, 1991, IAU symposium 147 "Fragmentation of Molecular Clouds and Star Formation", ed. E. Falgarone, F. Boulanger, and G. Duvert (Kluwer Academic Publishers), p.353, "Aperture Synthesis CS and 98 GHz Continuum Observations of Protostellar IRAS Sources in Taurus"
  2. N. Ohashi, R. Kawabe, M. Hayashi, and M. Ishiguro, 1994, IAU Colloquium 140 "Astronomy with Millimeter and Submillimeter Wave Interferometry", ed. M. Ishiguro, and W. J. Welch, p. 274, "The Nobeyama Millimeter Array Survey for Protoplanetary Disks around Protostar Candidates and T Tauri Stars in Taurus"
  3. T. Umemoto, N. Ohashi, Y. Murata, K. Tatematsu, M. Suzuki, 1994, IAU Colloquium 140 "Astronomy with Millimeter and Submillimeter Wave Interferometry", ed. M. Ishiguro, and W. J. Welch, p.245, "CS Lines and Dust Continuum Observations of the OMC2 Infrared Cluster"
  4. M. Tamura, N. Ohashi, G. Moriarty-Schieven, M. Hayashi, and N. Hirano, 1994, IAU Colloquium 140 "Astronomy with Millimeter and Submillimeter Wave Interferometry", ed. M. Ishiguro, and W. J. Welch, p.268, "CO Outflows in Low-Mass Protostar candidates in Taurus"
  5. N. Ohashi, R. Kawabe, M. Hayashi, and M. Ishiguro, 1994, Ap&SS, 212, 239, "The Nobeyama Millimeter Array Survey for Protoplanetary Disks around Protostar Candidates and T Tauri Stars in Taurus",
  6. N. Ohashi, M. Hayashi, 1995, Ap&SS, 224, 13, "Observations of Disks around Protostellar Sources with Nobeyama Millimeter Array"
  7. N. Hirano, T. Hasegawa, M. Hayashi, M. Tamura, and N. Ohashi, 1995, Ap&SS, 224, 113, "Physical Properties of the Outflow Sources in Taurus"
  8. N. Ohashi, and M. Hayashi, 1996, "Disks and Outflows around Young Stars", ed. S. Beckwith, J. Staude, A. Quetz, and A. Natta (Springer), p.44, "High Resolution Observations of Disks around Protostellar Sources with the Nobeyama Millimeter Array"
  9. N. Ohashi, 1997, "Star Formation Near and Far", ed. S. S. Holt, and L. G. Mundy (New York: AIP Press), P.93, "Dynamical Infalling Envelopes around Low-mass Protostar Candidates"
  10. N. Ohashi, 1999, "Star Formation 1999", ed. T. Nakamoto, p. 129, "Interferometric Imagings of Protostellar and Pre-Protostellar Envelopes"
  11. N. Ohashi, 2000, "Astrochemistry: From Molecular Clouds to Planetary Systems", eds. Y. C. Minh & E. F. van Dishoeck, p. 61, "Physical Properties of Molecular Envelopes in Low-Mass Star-Forming Regions"