Publications of The Korean Astronomical Society (천문학논총)

The Korean Astronomical Society (한국천문학회)
권호 표지
DOI QR코드

DOI QR Code

DEUTERATED METHANOL (CH3OD) IN THE HOT CORE OF THE MASSIVE STAR-FORMING REGION DR21 (OH)

무거운 별 탄생 지역인 DR21(OH) 천체에 대한 중수소화된 메탄올(CH3OD) 관측연구

  • Received : 2014.06.27
  • Accepted : 2014.07.21
  • Published : 2014.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

We have observed the deuterated methanol, $CH_3OD$, toward the hot core MM1 in the massive star-forming region DR21 (OH) using the Submillimeter Array with a high angular resolution of about 1 arcsecond. The position of the hot core associated with the sub-core MM1a was confirmed to coincide with the continuum peak where an embedded young stellar object is located. The column density of $CH_3OD$ was found to be about $(2{\pm}1){\times}10^{16}cm^{-2}$ toward the MM1a center. The abundance ratio $CH_3OD/CH_3OH$ was measured to be ~ 0.45, which is about the median value for low mass star-forming cores but much larger than those of the massive star-forming cores. The ratio is believed to change depending on, for example, the chemical condition, the temperature and the density of the source. This ratio may further depend on the evolutionary phase especially in the massive-star-forming cores. The sub-core MM1a is thought to be in the very early phase of star formation. This large abundance ratio found in this source indicates that even the massive star-forming cores, during a relatively short period in the very early stage of star formation, may also show a chemical state resulted from the cold and dense pre-collapsing phase, the enhanced deuteration as found in low mass star-forming cores.

Keywords

References

  1. Araya, E. D., Kurtz, S., Hofner, P., & Linz, H., 2009, Radio Continuum and Methanol Observations of DR21(OH), ApJ, 698, 1321 https://doi.org/10.1088/0004-637X/698/2/1321
  2. Argon, A. L., Reid, M., J., &, Menten, K. M., 2000, Interstellar Hydroxyl Masers in the Galaxy. I. The VLA Survey, ApJS, 129, 159 https://doi.org/10.1086/313406
  3. Batrla, W. & Menten, K. M., 1988, Detection of a Strong New Maser Line of Methanol Toward DR 21(OH), ApJ, 329, L117 https://doi.org/10.1086/185189
  4. Boogert, A. C. A., Pontoppidan, K. M., & Lahuis, F., et al., 2004, Spitzer Space Telescope Spectroscopy of Ices toward Low-Mass Embedded Protostars, ApJ, 154, 359 https://doi.org/10.1086/422556
  5. Charnley, S. B., Tielens, A. G. G. M., & Rodgers, S. D., 1997, Deuterated Methanol in the Orion Compact Ridge, ApJ, 482, L203 https://doi.org/10.1086/310697
  6. Fish, V. L., Muehlbrad, T. C., Pratap, P., et al., 2011, First Interferometric Images of the 36 GHz Methanol Masers in the DR21 Complex, ApJ, 729, 14 https://doi.org/10.1088/0004-637X/729/1/14
  7. Genzel, R. & Downes, D., 1977, $H_2O$ in the Galaxy: Sites of Newly formed OB Stars, A&AS, 30, 145
  8. Ho, P. T. P., Moran, J. M., & Lo, K. Y., 2004, The Submillimeter Array, ApJ, 616, L1 https://doi.org/10.1086/423245
  9. Hudson, R. L. & Moore, M. H., 1999, Laboratory Studies of the Formation of Methanol and Other Organic Molecules by Water+Carbon Monoxide Radiolysis: Relevance to Comets, Icy Satellites, and Interstellar Ices, Icarus, 140, 451 https://doi.org/10.1006/icar.1999.6144
  10. Jefferts, K. B., Penzias, A. A., & Wilson, R. W., 1973, Deuterium in the Orion Nebula, ApJ, 179, L57 https://doi.org/10.1086/181116
  11. Kogan, L. & Slysh, V., 1998, VLA Imaging of Class I Methanol Masers at 7 Millimeters with Angular Resolution approximately 0.2 Arcseconds, ApJ, 497, 800 https://doi.org/10.1086/305473
  12. Kurtz, S., Cesaroni, R., Churchwell, E., Hofner, P., & Walmsley, M., 2000, in Protostars and Planets IV, ed. V. Mannings, A. P. Boss, & S. S. Russell, 299 (Tucson: Univ. Arizona Press)
  13. Kurtz, S., Hofner, P., & Alvarez, C. V., 2004, A Catalog of CH3OH 7_0-6_1 A+ Maser Sources in Massive Star-forming Regions, ApJS, 155, 149 https://doi.org/10.1086/423956
  14. Linsky, J. L., Draine, B. T., Moos, H. W., et al., 2006, What Is the Total Deuterium Abundance in the Local Galactic Disk?, ApJ, 647, 1106 https://doi.org/10.1086/505556
  15. Mangum, J. C., Wootten, A., & Mundy, L. G., 1991, Synthesis Imaging of the DR 21(OH) Cluster. I - Dust Continuum and C(O-18) Emission, ApJ, 378, 576 https://doi.org/10.1086/170459
  16. Mauersberger, R., Henkel, C., Jacq, T., & Walmsley, C. M., 1988, Deuterated Methanol in Orion, A&A, 194, L1
  17. Minh, Y. C., Chen, H. -R., Su, Y. -N., & Liu, S. -Y., 2012, SMA Observations of the Hot Cores of DR21(OH), JKAS, 45, 157 https://doi.org/10.5303/JKAS.2012.45.6.157
  18. Motte, F., Bontemps, S., Schilke, P., Schneider, N., et al., 2007, The Earliest Phases of High-Mass Star Formation: a 3 Square Degree Millimeter Continuum Mapping of Cygnus X, A&A, 476, 1243 https://doi.org/10.1051/0004-6361:20077843
  19. Nagaoka, A., Watanabe, N., & Kouchi, A., 2005, H-D Substitution in Interstellar Solid Methanol: A Key Route for D Enrichment, ApJ, 624, L29 https://doi.org/10.1086/430304
  20. Neill, J. L., Crockett, N. R., Bergin, E. A., et al., 2013, Deuterated Molecules in Orion KL from Herschel/HIFI, ApJ, 777, 85 https://doi.org/10.1088/0004-637X/777/2/85
  21. Norris, R. P., Booth, R. S., Diamond, P. J., & Porter, N. D. 1982, Interferometric Observations of Four Protostellar OH Maser Sources, MNRAS, 201, 191 https://doi.org/10.1093/mnras/201.2.191
  22. Parise, B., Ceccarelli, C., Tielens, A. G. G. M., et al., 2006, Testing Grain Surface Chemistry: a Survey of Deuterated Formaldehyde and Methanol in Low-Mass Class 0 Protostars, A&A, 453, 949 https://doi.org/10.1051/0004-6361:20054476
  23. Peng, T. -C., Despois, D., Brouillet, N., et al., 2012, Deuterated Methanol in Orion BN/KL, A&A, 543, 152 https://doi.org/10.1051/0004-6361/201118310
  24. Plambeck, R. L. & Menten, K. M., 1990, 95 GHz Methanol Masers Near DR 21 and DR 21(OH), ApJ, 364, 555 https://doi.org/10.1086/169437
  25. Ratajczak, A., Taquet, V., & Kahane, C., et al., 2011, The Puzzling Deuteration of Methanol in Low- to High-Mass Protostars, A&A, 528, L13 https://doi.org/10.1051/0004-6361/201016402
  26. Rodgers, S. D. & Charnley, S. B., 2002, Multiply Deuterated Molecules and Constraints on Interstellar Chemistry, Planetary and Space Science, 50, 1125 https://doi.org/10.1016/S0032-0633(02)00073-9
  27. Roueff, E. & Gerin, M., 2003, Deuterium in Molecules of the Interstellar Medium, Space Sci. Rev., 106, 61 https://doi.org/10.1023/A:1024625301807
  28. Rygl, K. L. J., Brunthaler, A., & Sanna, A., et al., 2012, Parallaxes and Proper Motions of Interstellar Masers toward the Cygnus X Star-Forming Complex. I. Membership of the Cygnus X region, A&A, 539, 79 https://doi.org/10.1051/0004-6361/201118211
  29. Schneider, N., Bontemps, S., & Simon, R., et al., 2006, A New View of the Cygnus X Region. KOSMA 13CO 2 to 1, 3 to 2, and 12CO 3 to 2 Imaging, A&A, 458, 855 https://doi.org/10.1051/0004-6361:20065088
  30. Tielens, A. G. G. M., 1983, Surface Chemistry of Deuterated Molecules, A&A, 119, 177
  31. Viti, S. & Williams, D., 1999, Time-Dependent Evaporation of Icy Mantles in Hot Cores, MNRAS, 305, 755 https://doi.org/10.1046/j.1365-8711.1999.02447.x
  32. Wada, A., Mochizuki, N., & Hiraoka, K., 2006, Methanol Formation from Electron-irradiated Mixed H2O/CH4 Ice at 10 K, ApJ, 644, 300 https://doi.org/10.1086/503380
  33. Weber, A., Hodyss, R., Johnson, P., Willacy, K., & Kanik, I., 2009, Hydrogen-Deuterium Exchange in Photolyzed Methane-Water Ices, ApJ, 703, 1030 https://doi.org/10.1088/0004-637X/703/1/1030
  34. Woody, D. P., Scott, S. L., & Scoville, N. Z., et al., 1989, Interferometric Observations of 1.4 Millimeter Continuum Sources, ApJ, 337, L41 https://doi.org/10.1086/185374
  35. Zapata, L. A., Loinard, L., & Su, Y. -N., et al., 2012, Millimeter Multiplicity in DR21(OH): Outflows, Molecular Cores, and Envelopes, ApJ, 744, 86 https://doi.org/10.1088/0004-637X/744/2/86