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Abundances in the Gaseous Galactic Halo

Published online by Cambridge University Press:  14 August 2015

Ulysses J. Sofia
Ulysses J. Sofia*
Affiliation:
Villanova University Department of Astronomy and Astrophysics, Villanova, PA 19085 USA

Abstract

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The well measured gas-phase abundances in the low halo suggest that this region of the Galaxy has total (gas plus dust) metal abundances which are close to those in the solar neighborhood. The gas-phase abundances in the halo are generally higher than those seen in the disk, however, this affect is likely due to the destruction of dust in the halo clouds. Observations of high velocity clouds (HVCs) in the halo suggest that these clouds have metal abundances which are substantially lower than those measured for the local interstellar medium. These determinations, however, are often of lower quality than those for the low halo because of uncertainties in the hydrogen abundances along the sightlines, in the incorporation of elements into dust, and in the partial ionization of the clouds.

Type
II. Joint Discussions
Information
Highlights of Astronomy , Volume 11 , Issue 1: Highlights of Astronomy. As presented at the XXIIIrd General Assembly of the IAU (Part A), 1997 , 1998 , pp. 86 - 89
Copyright
Copyright © Kluwer 1998

References

Bowen, D.V. and Blades, J.C. 1993, ApJ, 403, L55 Google Scholar
Cardelli, J.A., Savage, B.D., Bruhweiler, F.C., Smith, A.M., Ebbets, D.C., Sembach, K.R. and Sofia, U.J. 1991, ApJ, 377, L57 Google Scholar
Cardelli, J.A., Savage, B.D., Sofia, U.J., Keenan, F.P. and Dufton, P.L. 1994, ApJ, 420, L29 Google Scholar
Cardelli, J.A., Sembach, K.R. and Savage, B.D. 1995, ApJ, 440, 221 Google Scholar
Danly, L., Lockman, F.J., Meade, M. and Savage, B.D. 1992, ApJS, 81, 125 Google Scholar
Fitzpatrick, E.L. 1996, ApJ, 473, L55 Google Scholar
Jenkins, E.B. 1987, in Interstellar Processes, eds. Hollenbach, D.J. and Thronson, H.A. Jr., Klewer Academic Publishers, Dordrecht, 533 Google Scholar
Jenkins, E.B. 1996, ApJ, 471, 292 Google Scholar
Jenkins, E.B. and Wallerstein, G. 1996, ApJ, 462, 758 Google Scholar
Lockman, F.J. and Gehman, C.S. 1991, ApJ, 382, 182 Google Scholar
Lu, L., Savage, B.D. and Sembach, K.R. 1994, ApJ, 426, 563 Google Scholar
Roth, K.C. and Blades, J.C. 1995, ApJ, 445, L95 Google Scholar
Savage, B.D., Cardelli, J.A. and Sofia, U.J. 1992, ApJ, 401, 706 Google Scholar
Savage, B.D., Lu, L., Weymann, R.J., Morris, S.L. and Giffiland, R. 1993, ApJ 404, 124 Google Scholar
Savage, B.D. and Massa, D. 1987, ApJ, 314, 380 Google Scholar
Savage, B.D. and Sembach, K.R. 1991, ApJ, 379, 245 Google Scholar
Savage, B.D. and Sembach, K.R. 1995, ApJ, 434, 145 Google Scholar
Schwartz, U.J., Wakker, B.P. and van Woerden, H. 1995, A&A, 302, 364 Google Scholar
Sembach, K.R. and Savage, B.D. 1996, ApJ. 457, 211 Google Scholar
Sembach, K.R., Stridel, C.C., Macke, R.J. and Meyer, D.M. 1995, ApJ, 445, L27 Google Scholar
Snow, T.P. and Witt, A.N. 1996, ApJ, 468, L65 Google Scholar
Sofia, U.J., Cardelli, J.A. and Savage, B.D. 1994, ApJ, 430, 650 Google Scholar
Sofia, U.J., Savage, B.D. and Cardelli, J.A. 1993, ApJ, 413, 251 Google Scholar
Spitzer, L. and Fitzpatrick, E.L. 1993, ApJ, 409, 299 Google Scholar
Spitzer, L. and Fitzpatrick, E.L., 1995, ApJ, 445, 196 Google Scholar
Wakker, B.P. and Schwartz, U.J. 1991, A&A, 250, 484 Google Scholar