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L1521F의 HCN(J=1-0) 분자선 전파 관측

Radio Observation of L1521F using HCN (J=1-0) Line

  • Sohn, Jung-Joo (Department of Earth Science Education, Korea National University of Education) ;
  • Lee, Chang-Won (Korea Astronomy and Space Science Institute)
  • 투고 : 2010.07.28
  • 심사 : 2010.08.15
  • 발행 : 2010.08.31

초록

본 연구에서는 황소자리 분자운에 위치한 L1521F-IRS의 운동학적 특성을 알아보기 위하여 HCN(J=1-0) 분자선 을 이용한 전파관측을 수행하여 분석하였다. 약한 밝기의 천체에 대한 높은 공간 분해능 지도 관측을 위하여 미국 Tucson에 위치한 Arizona Radio Observatory 12 m 망원경을 이용하였으며, 대상의 주변을 충분히 포함할 수 있도록 5지점${\times}5$지점 광역관측모드로 관측대상의 중심을 포함한 $3.7'{\times}3.7'$ 영역을 관측하였다. HCN 분자선 적분 밝기 분포자료는 분자운핵 L1521F가 고밀도 환경에서 분자의 심각한 결핍 현상이 없이 중심에서 강한 밝기를 보여 주고 있음을 보았다. L1521F에서 발견된 적외선원의 위치를 기준으로 동쪽방향에는 청색비대칭 분광선이 서쪽에는 적색비대칭 분광선이 존재하고 이들의 분포가 기존의 적외선영상에서 나타난 고깔모양과 잘 일치하는 모습을 보이고 있는 것으로 보아 L1521F-IRS에서 나오는 가스 쌍극류의 존재를 확인 할 수 있었다.

In this study, we investigated the kinematical properties of the L1521F-IRS in Taurus region using HCN (J=1-0) molecular line. The high resolution mapping has carried out by $5{\times}5$ point observations covering $3.7'{\times}3.7'$ area using a 12-m telescope of Arizona Radio Observatory in Tucsan, USA. L1521F which harbors the faint infrared L1521F-IRS, displayed a strong central concentration of integrated intensity in HCN without serious molecular depletion. It showed a symmetric kinematical structure with the opposite infall motion in either side of the central cores. It is a direct evidence of bipolar outflows in the core of L1521F.

키워드

참고문헌

  1. Aikawa, Y., Herbst, E., Roberts, H., Caselli, P., 2005, Molecular Evolution in Collapsing Prestellar Cores. III. Contraction of a Bonnor-Ebert Sphere. The Astrophysical Journal, 620, 330-346. https://doi.org/10.1086/427017
  2. Beichman, C.A., Myers, P.C., Emerson, J.P., Harris, S., Mathieu, R., Benson, P.J., Jennings, R.E., 1986, Candidate solar-type protostars in nearby molecular cloud cores. Astrophysical Journal, 307, 337-349. https://doi.org/10.1086/164421
  3. Bourke, T.L., Myers, P.C., Evans, N.J., II, Dunham, M.M., Kauffmann, J., et al. 2006, The Spitzer c2d Survey of Nearby Dense Cores. II. Discovery of a Low-Luminosity Object in the "Evolved Starless Core" L1521F. The Astrophysical Journal, 649, L37-L40. https://doi.org/10.1086/508161
  4. Buisson, G., Desbats, L., Duvert, G., Forveille, T., Gras, R., Guilloteau, S., and Valiron, P., 1994, CLASS Manual, Granoble: IRAM
  5. Crapsi, A., Caselli, P., Walmsley, C.M., Tafalla, M., Lee, C.W., Bourke, T.L., Myers, P.C., 2004, Observations of L1521F: A highly evolved starless core. Astronomy and Astrophysics, 420, 957-974. https://doi.org/10.1051/0004-6361:20035915
  6. Crapsi, A., Caselli, P., Walmsley, C.M., Myers, P.C., Tafalla, M., Lee, C.W., and Bourke, T.L., 2005, Probing the Evolutionary Status of Starless Cores through $N_2H^+$ and $N_2D^+$ Observations. The Astrophysical Journal, 619, 379-406. https://doi.org/10.1086/426472
  7. Dalgarno, A. and Lepp, S., 1984, Deuterium fractionation mechanisms in interstellar clouds. Astrophysical Journal, 287, L47-L50. https://doi.org/10.1086/184395
  8. Jijina, J., Myers, P.C., and Adams, F.C., 1999, Dense Cores Mapped in Ammonia: A Database. The Astrophysical Journal Supplement Series, 125, 161-236. https://doi.org/10.1086/313268
  9. Lee, C.W. and Myers, P.C., 1999, A Catalog of Optically Selected Cores. The Astrophysical Journal Supplement Series, 123, 233-250. https://doi.org/10.1086/313234
  10. Lee, C.W., Myers, P.C., and Tafalla, M., 2001, A Survey for Infall Motions toward Starless Cores. II. CS (2-1) and $N_2H^+$ (1-0) Mapping Observations. The Astrophysical Journal Supplement Series, 136, 703-734. https://doi.org/10.1086/322534
  11. Lee, J.-E., Bergin, E.A., and Evans, N.J., II 2004, Evolution of Chemistry and Molecular Line Profiles during Protostellar Collapse. The Astrophysical Journal, 617, 360-383. https://doi.org/10.1086/425153
  12. Mardones, D., Myers, P.C., Tafalla, M., Wilner, D.J., Bachiller, R., and Garay, G., 1997, A Search for Infall Motions toward Nearby Young Stellar Objects. Astrophysical Journal, 489, 719. https://doi.org/10.1086/304812
  13. Millar, T.J., Bennett, A., and Herbst, E., 1989, Deuterium fractionation in dense interstellar clouds. Astrophysical Journal, 340, 906-920. https://doi.org/10.1086/167444
  14. Murakami, H., Baba, H., Barthel, P. et al., 2007, The Infrared Astronomical Mission AKARI, Publications of the Astronomical Society of Japan, 59, S369, S376.
  15. Onishi, T., Mizuno, A., and Fukui, Y., 1999, A Very Dense Low-Mass Molecular Condensation in Taurus: Evidence for the Moment of Protostellar Core Formation. Publications of the Astronomical Society of Japan, 51, 257-262. https://doi.org/10.1093/pasj/51.2.257
  16. Oliveira, C.M., Hébrard, G., Howk, C.J., Kruk, J.W., Chayer, P., and Moos, H.W., 2003, Interstellar Deuterium, Nitrogen, and Oxygen Abundances toward GD 246, WD 2331-475, HZ 21, and Lanning 23: Results from the FUSE Mission. The Astrophysical Journal, 587, 235-255. https://doi.org/10.1086/368019
  17. Pilbratte, G.L., Riedinger, J.R., Passvogel, T. et al. 2010, Herschel Space Observatory. An ESA faccility for far-infrared and submilimetre astronomy, Astronomy and Astrophysics, 518, L1-L6. https://doi.org/10.1051/0004-6361/201014759
  18. Rawlings, J.M., Redman, M.P., Keto, E., and Williams, P.A., 2004, $HCO^+$ emission excess in bipolar outflows, Monthly Notices of the Royal Astronomical Society, 351, 1054-1062. https://doi.org/10.1111/j.1365-2966.2004.07855.x
  19. Sohn, J., Lee, C.W., Park, Y.-S., Lee, H.M., and Myers, P.C., 2007, Probing Inward Motions in Starless Cores Using the HCN (J=1-0) Hyperfine Transitions: A Pointing Survey toward Central Regions, The Astrophysical Journal, 664, 928-941. https://doi.org/10.1086/519159
  20. Tafalla, M., Santiago-Garcia, J., Myers, P.C., Caselli, P., Walmsley, C.M., and Crapsi, A., 2006, On the internal structure of starless cores, II. A moleclar survey of L498B and L517B. Astronomy and Astrophysics, 455, 577. https://doi.org/10.1051/0004-6361:20065311
  21. Terebey, S., Fich, M., Noriega-Crespo, A., Padgett, D.L., Fukagawa, M., 2009, Far-Infrared Observations of the Very Low Luminosity Embedded Source L1521F-IRS in the Taurus Star-Forming Region. The Astrophysical Journal, 696, 1918-1930. https://doi.org/10.1088/0004-637X/696/2/1918
  22. Werner, M.W., Roellig, T.L., Low, F.J., Rieke, G.H., Rieke, M., 2004, The Spitzer Space Telescope Mission. The Astrophysical Journal Supplement Series, 154, 1-9. https://doi.org/10.1086/422992
  23. Young, C.H., Bourke, T.L., Young, K.E., Evans, N.J., II, Jørgensen, J.K., 2004, Submillimeter Common-User Bolometer Array Mapping of Spitzer c2d Small Clouds and Cores. The Astronomical Journal, 132, 1998-2013.