An Observation of Diffuse Soft X-Ray Background and Distribution of Hot Interstellar Medium
Tóm tắt
The diffuse soft X-ray background in 0.07∼ 2.0 keV has been observed along a small circle with the angular width of 10– covering b=—57– ∼ 77– and crossing the galactic plane at l=125– and 283–. Observed spectra are well fitted with models emitted from a thin hot gas with two or multi-temperature components and attenuated by a slab or interspersed neutral gas clouds. However the multi-temperature component model has some difficulties to explain the diffuse component expected from observations of OVI absorption lines. The two temperature component model with interspersed clouds consistently interprets a physical state of the hot interstellar medium. It turned out that the hot interstellar medium interspersed with neutral clouds of a representative hydrogen column density of 1× 1020 cm-2has two temperature components (105.8 K,(1.2-4.5)× 106 K) and a disk-like distribution with the thickness of 580(± 100). {(p/k)/104cm-3 K} -2 pc at the pressure of p/k cm-3 K along the galactic plane. Its pressure (p/k) is obtained to be 1.4(+0.7,-0.5)× 104cm-3 K, assuming that hot gases responsible for the diffuse soft X-rays and OVI ions are in pressure equilibrium. This interpretation qualitatively agrees with the theoretical prediction proposed by McKee and Ostriker.
Tài liệu tham khảo
Allen, C.W.: 1973, Astrophysical Quantities, Athlone press, London.
Berkhuijsen, E.M.: 1973, Astron. Astrophys. 24, 143.
Berkhuijsen, E.M., Haslam, C.G.T. and Salter, C.J.: 1970, Nature 225, 364.
Bloch, J.J., Jahoda, K., McCammon, D., Sanders, W.T. and Snowden: 1986, Astrophys. J. Lett. 308, L59.
Bohlin, R.C.: 1975, Astrophys. J. 200, 139.
Bohlin, R.C., Savage, B.C. and Drake, J.F.: 1978, Astrophys. J. 224, 132.
Bowyer, S.: 1994, Science 263, 55.
Bowyer, S., Lieu, R., Sidher, S.D., Lampton, M. and Kunde, J.: 1995, Nature 375, 212.
Brown, R.L. and Gould, R.J.: 1970, Phys. Rev. D 1, 2252.
Bruhweiler, F.C. and Kondo, Y.: 1982, Astrophys. J. 259, 232.
Burstein, P., Borken, R.J., Kraushaar, W.L. and Sanders, W.T.: 1977, Astrophys. J. 213, 405.
Burrows, D.N. and Mendenhall, J.A.: 1991, Nature 351, 629.
Caillault, J.-P., Helfand, D.J., Nousek, J.A. and Takalo, L.O.: 1986, Astrophys. J. 304, 318.
Cowie, L.L., Jenkins, E.B., Songaila, A. and York, D.G.: 1979, Astrophys. J. 232, 467.
Cowie, L.L. and McKee, C.F.: 1977, Astrophys. J. 211, 135.
Cox, D.P.: 1972a, Astrophys. J. 178, 159.
Cox, D.P.: 1972b, Astrophys. J. 178, 169.
Cox, D.P. and Smith, B.W.: 1974, Astrophys. J. Lett. 189, L105.
Cox, D.P.: 1981, Astrophys. J. 245, 534.
Cox, D.P.: 1996, in: S. Bowyer and R.F. Malina (eds.), Astrophysics in the Extreme Ultraviolet, Kluwer acad. Publ., Dordrecht, 274.
Cox, D.P. and Snowden, S.L.: 1986, Adv. Space Res. 6, 97.
Daltabuit, E. and Meyer, S.: 1972, Astron. Astrophys. 20, 415.
Field, G.B.: 1975, Lectures at 1974 Les Houches Summer School in Theoretical Physics.
Fried, P.M., Nousek, J.A., Sanders, W.T. and Kraushaar, W.L.: 1980, Astrophys. J. 242, 987.
Frisch, P.: 1994, Science 265, 1423.
Frisch, P.C. and York, D.G.: 1983, Astrophys. J. Lett. 271, L59.
Garmire, G.P., Apparo, K.M.V., Burrows, D.N., Fink, R.L. and Kraft, R.P.: 1992, Astrophys. J. 399, 694.
Hayakawa, S., Kato, T., Nagase, F., Yamashita, K., Murakami, T. and Tanaka, Y.: 1977, Astrophys. J. Lett. 213, L109.
Hayakawa, S., Kato, T., Nagase, F., Yamashita, K. and Tanaka, Y.: 1978, Astron. Astrophys. 62, 21.
Iwan, D.C.: 1980, Astrophys. J. 239, 316.
Jakobsen, P. and Kahn, S.M.: 1986, Astrophys. J. 309, 682.
Jenkins, E.B.: 1978a, Astrophys. J. 219, 845.
Jenkins, E.B.: 1978b, Astrophys. J. 220, 107.
Jenkins, E.B. and Meloy, D.A.: 1974, Astrophys. J. Lett. 193, L121.
Jordan, C.: 1969, Mon. Not. R. Astron. Soc. 142, 501.
Kahn, S.M. and Jakobsen, P.: 1988, Astrophys. J. 329, 406.
Kato, T.: 1976, Astrophys. J. Suppl. 30, 397.
Levine, A., Rappaport, S., Halpern, J. and Walter F.: 1977, Astrophys. J. 211, 215.
Long, K.S., Patterson, J.R., Moore, W.E. and Garmire, P.G.: 1977, Astrophys. J. 212, 427.
Marshall, F.J. and Clark, G.W.: 1984, Astrophys. J. 287, 633.
McKee, C.F. and Ostriker, J.P.: 1977, Astrophys. J. 218, 148.
McCammon, D., Bunner, A.N., Colenman, P.L. and Kraushaar, W.L.: 1971, Astrophys. J. Lett. 168, L23.
McCammon, D., Burrows, D.N., Sanders, W.T. and Kraushaar, W.L.: 1983, Astrophys. J. 269, 107.
McCammon, D. and Sanders, W.T.: 1990, Annu. Rev. Astron. Astrophys. 14, 373.
Myers, P.C.: 1978, Astrophys. J. 225, 380.
Nousek, J.A., Fried, P.M., Sanders, W.T. and Krausaar, W.L.: 1982, Astrophys. J. 258, 83.
Paresce, F. and Stern, R.: 1981, Astrophys. J. 248, 89.
Rosner, R., Avni, Y., Bookbinder, J., Giacconi, R., Golub, F.R., Harnden, J., Maxson, C.W., Topka, K. and Vaiana, G.S.: 1981, Astrophys. J. Lett. 249, L5.
Sanders, W.T., Kraushaar, W.L., Nousek, J.A. and Fried, P.M.: 1977, Astrophys. J. Lett. 217, L87.
Sanders, W.T., Edgar, R.J., McCammon, D. and Kraushaar, W.L.: 1996, in: K. Yamashita and T. Watanabe (eds.), UV and X-ray Spectroscopy of Astrophysical and Laboratory Plasmas, Univ. Acad. Press, Tokyo, 131.
Savage, B.D., Bohlin, R.C., Drake, J.F. and Budich, W.: 1977, Astrophys. J. 216, 291.
Schmitt, J.H.M.M., Collura, A., Sciortino, S., Vaiana, G.S., Hardnden, F.R., Jr. and Rosner, R.: 1990, Astrophys. J. 365, 704.
Shapiro, P.R. and Field, G.B.: 1976, Astrophys. J. 205, 762.
Shapiro, P.R. and Moore, R.T.: 1976, Astrophys. J. 207, 460.
Shelton, R.L. and Cox, D.P.: 1994, Astrophys. J. 434, 599.
Snowden, S.L., Cox, D.P., McCammon, D. and Sanders, W.T.: 1990, Astrophys. J. 354, 211.
Snowden, S.L., Mebold, U., Hirth, W., Herbstmeier, U. and Schmitt, J.H.M.M.: 1991, Science 252, 1529.
Snowden, S.L., Freyberg, M.J., Plucinsky, P.P., Schmitt, J.H.M.M., Trumper, J., Voges, W., Edgar, R.J., McCammon, D. and Sanders, W.T.: 1995, Astrophys. J. 454, 643.
Spitzer, L.: 1978, Physical Processes in the Interstellar Medium, John Wiley & Sons, Chapter 11.
Stern, R. and Bowyer, S.: 1979, Astrophys. J. 230, 755.
Tanaka, Y. and Bleeker, J.A.M.: 1977, Space Sci. Rev. 20, 815.
Tsumeni, H. and Inoue: 1980, Publ. Astron. Soc. Jpn. 32, 247.
West, R.G., Willingale, R., Pye, J.P. and Sumner, T.J.: 1996, in: S. Bowyer and R.F. Malina (eds.), Astrophysics in the Extreme Ultraviolet, Kluwer Acad. Publ., Dordrecht, 289.