A synthetic view at large scale of local molecular clouds

  • F. Lebrun
Part I: Nearby Molecular Clouds as Part of Larger Structure
Part of the Lecture Notes in Physics book series (LNP, volume 237)


Local molecular clouds can be studied in many ways at various wavelenghts from radio waves to γ rays. None of these observations leads alone to a single and unambigous interpretation. Simplifying assumptions are generarally made which limit the degree of confidence of the results obtained. As an example it is often assumed, especially in the local interstellar medium, that some quantities are constant. Among them I can list, the gas to dust ratio, N(H2)/Wco ratio, the HI spin temperature, the cosmic-ray density, etc...

Synthetic studies may then help resolving some of the ambiguities resulting from these assumptions. An example is discussed based on the comparison of galaxy counts, ~ rays, U-V absorption lines, CO, star counts and reddening. Furthermore, these observations are also very often complementary. The 21 cm sky surveys provide an accurate and nearly fully sampled map of atomic hydrogen, but does not depict the H2 distribution. Gamma rays can trace both species but are not very accurate. The reddening measurements cannot provide a fully sample sky survey and are also not very accurate but are probably the only way of estimating cloud distances in the solar neighbourhood (d < 500 pc), which are essential for estimating sizes and masses.


Column Density Solar Neighbourhood Spin Temperature Gould Belt Local Interstellar Medium 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Baran, G.P. and Thaddeus, P. 1977, B.A.A.S., 9, 353.Google Scholar
  2. Barnard, E.E. 1927, Photographic Atlas of Selected Regions of the Milky Way, ed. E.B. Frost, M.R. Calvert (Washington dc: Carnegie Institute of Washington).Google Scholar
  3. Bloemen, J.B.G.M. 1984, Astr.AP., in press.Google Scholar
  4. Bloemen, J.B.G.M. et al. 1984, Astr.Ap., 139, 37.Google Scholar
  5. Bignami, G.F., and Morfill, G.E. 1980, Astr.Ap., 87, 85.Google Scholar
  6. Bohlin, R.C., Savage, B.D., and Drake, J.F. 1978, Ap.J., 224, 132.Google Scholar
  7. Burstein, D. and Heiles, C. 1978, Ap.J. 225, 40.Google Scholar
  8. Caraveo, P. et al. 1980, Astr.Ap., 91, L3.Google Scholar
  9. Caraveo, P. et al. 1981, Proc.17th Int.Cosmic Ray Conf., Paris 1, 139Google Scholar
  10. Casse, M. and Paul, J.A. 1980, Ap.J., 237, 236.Google Scholar
  11. Cernicharo, J. and Bachiller, R. 1984, Astr.Ap.Suppl., in press.Google Scholar
  12. Crovisier, J., Kazes, I., and Aubry, D. 1978, Astr.Ap.Suppl., 32, 205.Google Scholar
  13. Crovisier, J., Kazes, I., and Aubry, D. 1980, Astr.Ap.Suppl., 41, 229.Google Scholar
  14. Dame, T.M. and Thaddeus P. 1984, in preparation.Google Scholar
  15. Dickey, J.M., Salpeter, E.E., and Terzian, Y. 1978, AP.J.Suppl., 36, 77.Google Scholar
  16. Dickman, R.L. 1978, Ap.J.Suppl., 37, 407.Google Scholar
  17. Encrenaz, P.J., Falgarone E. and Lucas R. 1975, Astr.Ap. 44, 73.Google Scholar
  18. Fichtel, C.E., Simpson, G.A., and Thompson, D.J. 1978, Ap.J., 222, 833.Google Scholar
  19. Garzoli, S.L., and Varsavsky, C.M. 1966, Ap.J., 145, 79.Google Scholar
  20. Heiles, C. 1967, Ap.J.Google Scholar
  21. Heiles,C. and Habing H.J. 1974, Astr.Ap.Suppl., 14, 1.Google Scholar
  22. Heiles, C. 1976, Ap.J., 204, 379.Google Scholar
  23. Heiles, C. and Cleary, M.N. 1979, Aust.J.Phys.Suppl., 47, 1.Google Scholar
  24. Heiles, C., Chu Y.-H., Reynolds, R.J., Yegingil I., Troland T.H. 1980, Ap.J., 242, 533.Google Scholar
  25. Hubble, E.P. 1933, Mt.W.Contr., 21, 139.Google Scholar
  26. Jenkins, E.B., and Savage B.D. 1974, Ap.J., 187, 243.Google Scholar
  27. Knapp, G.R. and Kerr F.J. 1974, Astr.Ap., 35, 361.Google Scholar
  28. Kutner, M.L. 1973, Molecules in the Galactic Environment, ed. M.A. Gordon and L.E Snyder (Wiley, New York)Google Scholar
  29. Lebrun, F. and Paul, J.A. 1978, Astr.Ap., 65, 187.Google Scholar
  30. Lebrun, F. and Paul, J.A. 1983, Ap.J., 266, 276.Google Scholar
  31. Lebrun, F. and Huang, Y.-L. 1984, Ap.J., 281, 634.Google Scholar
  32. Lebrun, F. et al. 1982, Astr.Ap., 107, 390.Google Scholar
  33. Lebrun, F. et al. 1983, Ap.J., 274, 231.Google Scholar
  34. Lilley, A.E. 1955, Ap.J., 121, 559.Google Scholar
  35. Lucke, P.B. 1978, Astr.Ap. 64, 367.Google Scholar
  36. Lundmark, K. 192: Upp.Obs.Medd., 12, 1.Google Scholar
  37. Lynds, B.T. 1962, Ap.J.Suppl., 7, 1.Google Scholar
  38. Maddalena, R.J., Morris, M., Moscowitz, J., and Thaddeus P., in preparation.Google Scholar
  39. McCammon, D. et al. 1983, Ap.J., 269, 107.Google Scholar
  40. McCuskey, S.W. 1938, Ap.J., 88, 209.Google Scholar
  41. Meyers, P.C. 1975, Ap.J. 198, 331.Google Scholar
  42. Morfill, G.E., Volk, H.J., Drury, L., Forman, M., Bignami, G.F. and Caraveo, P.A. 1981, Ap.J., 246, 810.Google Scholar
  43. Neckel Th. and Klare G. 1980, Astr.Ap.Suppl., 42, 251.Google Scholar
  44. Paresce, F. 1984, A.J., 89, 1022.Google Scholar
  45. Penzias, A.A., Jefferts, K.B., and Wilson, R.W. 1971, Ap.J., 165, 229.Google Scholar
  46. Perry C.L. and Johnston L. 1962, Ap.J., 50, 451.Google Scholar
  47. Racine, R. 1969, A.J., 74, 1073.Google Scholar
  48. Rossano, G.S. 1978, A.J., 83, 234.Google Scholar
  49. Ryter C., Cesarsky, C.J. and Audouze, J. 1975, Ap.J., 198, 103.Google Scholar
  50. Sanders, D.B., Solomon P.M. and Scoville N.Z. 1984, Ap.J. 276, 182.Google Scholar
  51. Savage, B.D. and Jenkins E.B. 1972, Ap.J. 172, 491.Google Scholar
  52. Shane, C.D. and Wirtanen C.A. 1967, Pub.Lick.Obs., 22, 1.Google Scholar
  53. Strong, A.W. and Wolfendale, A.W. 1981, Phil.Trans.Roy.Soc.Lond.A. 301, 541.Google Scholar
  54. Strong, A.W. and Lebrun, F. 1982, Astr.Ap., 105, 159.Google Scholar
  55. Strong, A.W., Murray, J.D., Riley, P.A., and Osborne, J.L. 1982, M.N.R.A.S., 201, 495.Google Scholar
  56. Strong, A.W. et al. 1982, Astr.Ap., 115, 404.Google Scholar
  57. Strong, A.W. 1963, M.N.R.A.S. 202, 1025.Google Scholar
  58. Strong, A.W. 1984, Astr.Ap., in press.Google Scholar
  59. Sturch, C. 1969, A.J., 67,37.Google Scholar
  60. Swanenburg B.N. et al. 1981, Ap.J. 243, L69.Google Scholar
  61. Tucker, K.D., Dickman, R.L., Encrenaz, P.J. and Kutner, M.L. 1976, Ap.J., 210, 679.Google Scholar
  62. van Hoof, A. 1969, B.A.N.Suppl., 3, 137.Google Scholar
  63. van Rhijn, P.J. 1929, Publ.Kapteyn Astron.Lab., 43.Google Scholar
  64. Weaver, H.,Williams, R.W. 1973, Astr.Ap.Suppl., 8, 1Google Scholar
  65. Wesselius P.R. and Sancisi R. 1971, Astr.Ap., 11, 246.Google Scholar
  66. Wilson, R.W., Jefferts, K.B., and Penzias, A.A. 1970, Ap.J., 161, L43.Google Scholar
  67. Wouterloot, J. 1984, Astr.Ap., 135, 32.Google Scholar

Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • F. Lebrun
    • 1
  1. 1.Service d'Astrophysique, C.E.N. SaclayGif/Yvette CEDEXFrance

Personalised recommendations