本論文中，我們探討從五個含碳量高的漸近巨星分支星的環星包層所發射出來的HC3N (J=5-4)分子轉動譜線觀測結果。觀測目標包含LP And，V Cyg，IRAS 22272＋5435，V384 Per及RAFGL 2155。我們使用Very Large Array針對7毫米波段(45490.3 MHz)作觀測。我們獲得約1.5角秒的高解析度足夠讓我們解析出HC3N在環星包層中的分布為中空球殼狀結構。如此的分布與先前由其他漸近巨星分支星的環星包層所做出的HC3N分子形成之化學模型吻合。不過我們仍發現有些許成塊狀或是長條狀等不對稱分布。另外我們還發現環星包層的大小與中心星球的質量損失率有關。我們高解析的觀測結果為現階段含碳量高之環星包層的化學模型提供了非常有用的限制條件。

In this thesis, we investigated the HC3N (J＝5-4) emission at 45490.3 MHz from the circumstellar envelopes of five carbon rich stars (LP And, V Cyg, IRAS 22272＋5435, V384 Per, RAFGL 2155). The observations were carried out using the Very Large Array of the National Radio Astronomical Observatory. The high angular resolution of ∼1”.5 allows us to resolve the distribution of HC3N in these envelopes into hollow shell structure in constant expansion. Such distribution is in broad agreement with prediction of chemical models on the formation of HC3N molecules. We also find that the distribution of HC3N is clumpy and in a few cases asymmetric. Interestingly, we find a clear relation between mass loss rate from the central star and the linear size of the envelope. Our results provide very useful constraints to the current chemical models for the carbon rich envelope.

Audinos, P., Kahane, C., Lucas, R. 1994, A&A, 287, L5

Bachiller, R., Fuente, A., Bujarrabal, V., et al. 1997, A&A 319, 235

Bennett et al., The Cosmic Perspective, 2nd Edition, Addison Wesley.

Bieging, J.H., Tafalla, M. 1993, AJ 105, 576

Bieging, J. H., Wilson, C. D. 2001, AJ, 122, 979

Buss, R. H. Jr., Cohen, M., Tielens, A. G. G. M., et al. 1990, ApJ, 365, 23

Cherchneff, I., Glassgold, A. E. 1993, ApJ, 419, L41

Cohen, M., Hitchon, K. 1996, AJ, 111, 962

Fong, D., Meixner, M., Sutton, E. C., et al. 2006, ApJ, 652, 1626

Geballe, T. R., Tielens, A. G. G. M., Kwok, S., Hrivnak, B. J. 1992, ApJ, 387, 89

Glassgold, A. E., Lucas, R., Omont, A. 1986, A&A, 157, 35

Glassgold, A. E., Mamon, G. A., Huggins, P. J. 1991, ApJ, 373, 254

Gledhill, T. M., Chrysostomou, A., Hough, J. H., Yates, J. A. 2001, MNRAS, 322, 321

Groenewegen, M. A. T., Whitelock, P. 1996, MNRAS, 281, 1347

Guelin, M., Neininger, N., Cernicharo, J. 1998, A&A, 335, L1

Habing, H. J., Olofsson, H. 2004, Asymptotic Giant Branch stars, Astronomy and Astrophysics library, pp12-15

Hasegawa, T. I., Kwok, S. 2001, ApJ, 562, 824

Hrivnak, B. J., Kwok, S. 1991, ApJ, 371, 631

Hrivnak, B. J. 1995, ApJ, 438, 341

Justtanont, K., Barlow, M. J., Skinner, C. J., et al. 1996, A&A, 309, 612

Kawaguchi, K., Kasai, Y., Ishikawa, S., Kaifu, N. 1995, PASJ, 47, 853.

Knapp, G. R., Morris, M. 1985, ApJ, 292, 640

Knapp, G. R., Young, K., Lee, E., Jorissen, A. 1998, ApJS, 117, 209

Kwok, S., Volk, K. M., Hrivnak, B. J. 1989, ApJL, 345, L51

Kwok, S., Hrivnak, B. J., Su, K. Y. L. 2000, ApJ, 544, L149

Lindqvist, M., Nyman, L.-A., Olofsson, H., Winnberg, A. 1988, A&A, 205, L15

Lindqvist, M., Schoier, F. L., Lucas, R., Olofsson, H. 2000, A&A, 361, 1036

Lucas, R., Guelin, M. 1999, IAU symposium 191, pp305

Mauron, N., Higgins, P. J. 2006, A&A, 452, 257

Meixner, M., Skinner, C. J., Graham, J. R., Keto, E., Jernigan, J. G., Arens, J. F. 1997, ApJ, 482, 897

Millar, T. J., Herbst, E. 1994, A&A, 288, 561

Millar, T. J., Herbst, E., Bettens, R. P. A. 2000, MNRAS, 316, 195

Morris, M., Lucas, R., Omont, A. 1985, A&A, 142, 107

Olivier, E. A., Whitelock, P., Marang, F. 2001, MNRAS, 326, 490

Olofsson, H., Johansson, L. E. B., Hjalmarson A., Nguyen-Quang-Rieu 1982, A&A, 107 128

Olofsson, H., Eriksson, K., Gustafsson, B., Carlstrom, U. 1993, ApJS, 87, 305

Omont, A., Loup, C., Forveille, T., te Lintel Hekkert, P., Habing, H., sivagnanam, P. 1993, A&A, 267, 515

Omont, A., Moseley, S. H., Cox, P., et al. 1995, ApJ, 454, 819

Pottasch, S. R., Parthasarathy, M. 1988, A&A, 192, 182

Schoier, F. L., Olofsson, H. 2000, A&A, 359, 586

Schoier, F. L., Olofsson, H. 2001, A&A, 368, 969

Ueta, T., Meixner, M., Bobrowsky, M. 2000, ApJ, 528, 861

Ueta, T., Meixner, M., Hinz, P. M., et al. 2001, ApJ, 557, 831

van der Veen, W., Habing, H. 1988, A&A, 194, 125

Van Winckel, H. 2003, ARA&A, 41, 291

Wallerstein, G., Knapp, G. R. 1998, ARA&A, 36, 369

Wootten, A., Nguyen-Quang-Rieu, Truong-Bach 1994, A&A, 290, 198

Zacs, L., Klochkova, V. G., Panchuk, V. E. 1995, MNRAS, 275, 764