Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-10T13:44:25.051Z Has data issue: false hasContentIssue false
  • English
  • Français

The Chemical Enrichment of the Diffuse Gas in the Outer Galaxy and the Abundance Gradient of the Milky Way

Published online by Cambridge University Press:  01 June 2007

Limin Song ,
Todd M. Tripp ,
David V. Bowen  and
Kenneth R. Sembach
Limin Song
Affiliation:
Astronomy Department, University of Massachusetts, Amherst, MA 01002, USA email: limin@astro.umass.edu, tripp@fcrao1.astro.umass.edu
Todd M. Tripp
Affiliation:
Astronomy Department, University of Massachusetts, Amherst, MA 01002, USA email: limin@astro.umass.edu, tripp@fcrao1.astro.umass.edu
David V. Bowen
Affiliation:
Princeton University Observatory, Princeton, NJ 08544, USA email: dvb@astro.princeton.edu
Kenneth R. Sembach
Affiliation:
Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218, USA email: sembach@stsci.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Using data from HST/STIS (Hubble Space Telescope / Space Telescope Imaging Spectrograph) and FUSE (Far Ultraviolet Spectroscopic Explorer) toward two QSOs, H1821+643 and HS0624+6907, we find that the overall metallicity of the Galactic “Outer Arm” is Z=0.3−0.5 Z⊙ with underabundant nitrogen and little depletion by dust. The results are consistent with those based on H II region measurements in the outer galaxy and provide additional constrains on models of the Galactic abundance gradient and Milky Way (MW) chemical evolution. The lower metallicity observed in the outer galaxy is consistent with abundance patterns observed in higher redshift damped Lyα absorbers (DLAs) extrapolated to z=0. The slow metallicity evolution of DLAs could be due to the larger cross sections of the outer regions of galaxies combined with the observed metallicity gradients.

Keywords

abundance gradientmetallicity
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 3 , Symposium S244: Dark Galaxies and Lost Baryons , June 2007 , pp. 381 - 382
Copyright
Copyright © International Astronomical Union 2008

References

Chiappini, C., Matteucci, F. & Romano, D. 2001, ApJ 554, 1044CrossRefGoogle Scholar
Dessauges-Zavadsky, M., Proux, C., Kim, T.-S., D'Odorico, S. & McMahon, R. G. 2003, MNRAS 345, 447CrossRefGoogle Scholar
Ferland, G. J., Korista, K. T., Verner, D. A., Ferguson, J. W., Kingdon, J. B. & Verner, E. M. 1998, PASP 110, 761CrossRefGoogle Scholar
Fitzpatrick, E. L. & Spitzer, L. Jr. 1997, ApJ 475, 623CrossRefGoogle Scholar
Haud, U. 1992, MNRAS 257, 707CrossRefGoogle Scholar
Prochaska, J. X., Gawiser, E., Wolfe, A. M., Castro, S. & Djorgovski, S. G. 2003, ApJ 595, 9CrossRefGoogle Scholar
Savage, B. D. & Sembach, K. R. 1991, ApJ 379, 245CrossRefGoogle Scholar
Wakker, B. P., Kalberla, P. M. W., van Woerden, H., de Boer, K. S. & Putman, M. E. 2001, ApJS 136, 537CrossRefGoogle Scholar