Abstract
We outline a method to explore the column density of the Local Interstellar Medium (LISM) using absorptions in the resonance H and K lines of Mgii. The intrinsic strengths of these lines in the temperature and density conditions prevailing in warm clouds (T eff<104 K) in the LISM allows them to be used to explore many lines of sight where lines such a NaD and Caii H and K are too weak, but where Lα is saturated. The number of measurable lines-of-sight is greatly enhanced by using cool stars as the background emitters, but this implies reliable separation of the LISM components from stellar chromospheric selfabsorptions. We explain how to do this, and how to use a combination of column density and radial velocity data to measure the spatial extent and the physical parameters of the single cloud in which the Sun is embedded. This proves to be an oblate spheroid, of characteristic diameter 8 pc, withT eff ∼ 104 K,n(Hi) of 0.1 cm−3 and a mass <5M ⊙, streaming in the LSR from a point 1″=4°,B″=+16° with velocity equal to 16 km s−1, and is surrounded by the much hotter lower density ionized gas of the local supernova bubble.
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Anderson, R. C. and Weiler, E. J.: 1978,Astrophys. J. 224, 143.
Beckman, J. E., Crivellari, L., and Selvelli, P. L.: 1982,Astron. Astrophys. Suppl. 47, 295.
Beckman, J. E., Crivellari, L., Franco, M. L., Molaro, P., and Vladilo, G.: 1984, in ‘Local Interstellar Medium’,IAU Colloq. 81, 67.
Bruhweiler, F. C., Oegerle, W., Weiler, E., Stencel, R., and Kondo, Y.: 1984,Future of Ultraviolet Astronomy Based on Six Years of IUE Research, NASA Publ. CP-2349, p. 200.
Bruhweiler, F. C. and Vidal-Madjar, A.: 1987, in Y. Kondo (ed.),Scientific Accomplishements of the IUE, D. Reidel Publ. Co., Dordrecht, Holland, p. 467.
Chassefière, E., Bertaux, J. L., Lallement, R., and Kurt, V. G.: 1986,Astron. Astrophys. 160, 229.
Cox, D. P. and Snowden, S. L.: 1986,Adv. Space Res. 6, 97.
Crivellari, L., Franco, M. L., Molaro, P., Vladilo, G., and Beckman, J. E.: 1983,Astron. Astrophys. Suppl. 52, 135.
Ferlet, R., Lallement, R., and Vidal-Madjar, A.: 1986,Astron. Astrophys. 163, 204.
Franco, M. L., Crivellari, L., Molaro, P., Vladilo, G., Ramella, M., Morossi, C., Allochio, C., and Beckman, J. E.: 1984,Astron. Astrophys. Suppl. 58, 693.
Frisch, P.: 1986,Adv. Space Res. 16, 345.
Frisch, P., York, D. G., and Fowler, J. R.: 1987,Astrophys. J. 320, 842.
Génova, R., Beckman, J. E., Molaro, P. and Vladilo, G.: 1986,Adv. Space Res. 6, 53.
Génova, R., Molaro, P., Vladilo, G., and Beckman, J. E.: 1989,Astrophys. J. (submitted).
Kondo, Y., Talent, D. L., Barker, E. S., Dufour, R. J., and Modisette, J. L.: 1978,Astron. Astrophys. 220, L97.
Kulkarni, S. R. and Heiles, C.: 1987, in D. J. Hollenbach and H. A. Thronson, Jr. (eds.),Interstellar Processes, D. Reidel Publ. Co., Dordrecht, Holland, p. 87.
Lallement, R., Vidal-Madjar, A., and Ferlet, R.: 1986,Astron. Astrophys. 168, 225.
Landsman, W. B., Murthy, J., Hency, R. C., Moos, H. W., Linsky, J. L., Vidal-Madjar, A., and Gry, C.: 1986,Adv. Space Res. 6, 87.
Molaro, P., Vladilo, G., and Beckman, J. E.: 1986,Astron. Astrophys. 161, 339.
stokes, G. M.: 1978,Astrophys. J. Suppl. 36, 115.
Vidal-Madjar, A., Ferlet, R., Gry, C., and Lallement, R.: 1986,Astron. Astrophys. 155, 407.
Vladilo, G., Beckman, J. E., Crivellari, L., Franco, M. L., and Molaro, P.: 1985,Astron. Astrophys. 144, 81.
Vladilo, G., Molaro, P., Crivellari, L., Foing, B. H., and Beckman, J. E., and Génova, R.: 1987,Astron. Astrophys. 185, 233.
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Génova, R., Beckman, J.E., Vladilo, G. et al. The local interstellar medium: A test-bed for the galactic ISM. Astrophys Space Sci 156, 243–249 (1989). https://doi.org/10.1007/BF00646373
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DOI: https://doi.org/10.1007/BF00646373