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On the Origin of Metallicity in Lyman-Alpha Forest Systems

Published online by Cambridge University Press:  19 July 2016

M. Chiba
Affiliation:
National Astronomical Observatory, Mitaka, Tokyo 181, JAPAN
B. B. Nath
Affiliation:
Raman Research Institute, Bangalore-560080, INDIA

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Several recent observations indicate that even the low H I column density Lyα absorption lines may not be primordial, as they were previously thought to be. High-resolution observations using the Keck telescope (Cowie et al. 1995; Tytler et al 1995.; Songaila & Cowie 1996) have revealed that a large fraction of Lyα absorption lines with H I column density as low as NHI ~ 1014 cm−2 at redshift z ~ 3 are associated with metal lines (C IV). This fraction, hereafter denoted as fm, is estimated as 0.5-0.75. On the other hand, there is an indication that at low z a large fraction of Lyα absorption lines are directly associated with halos of visible galaxies. This fraction is hereafter denoted as fg. Lanzetta et al. (1995, hereafter LBTW) claimed fg ~ 0.6 at z ≲ 1 (see also Bowen, Pettini & Boyle 1997).

Type
Conference Papers in order of Presentation
Copyright
Copyright © 2002 

References

Bowen, D.V., Pettini, M., & Boyle, B.J. 1997, MNRAS, in press (astro-ph/9707306).Google Scholar
Chiba, M. & Nath, B.B. 1997, ApJ, 483, 638.Google Scholar
Cowie, L.L., Songaila, A., Kim, T.S., & Hu, E.M. 1995, AJ, 109, 1522.Google Scholar
Lanzetta, K.M., Wolfe, A.M., & Turnshek, D.A. 1995, ApJ, 440, 435.CrossRefGoogle Scholar
Lanzetta, K.M., Bowen, D.B., Tytler, D., & Webb, J.K. 1995, ApJ, 442, 538 (LBTW).Google Scholar
Lu, L., Sargent, W.L.W., Barlow, T.A., Churchill, C.W., & Vogt, S.S. 1996, ApJS, 107, 475.CrossRefGoogle Scholar
Mo, H.J. 1994, MNRAS, 269, L49.Google Scholar
Pagel, B.E.J. 1989, Rev. Mexicana Astron. Astrofis., 18, 161.Google Scholar
Rees, M.J. 1986, MNRAS, 218, 25P.CrossRefGoogle Scholar
Schuster, W.J. & Nissen, P.E. 1989, A&A, 222, 69.Google Scholar
Songaila, A., & Cowie, L.L. 1996, AJ, 112, 335.Google Scholar
Thoul, A.A. & Weinberg, D.H. 1996, ApJ, 465, 608.Google Scholar
Tytler, D., Fan, X.-M., Buries, S., Cottrell, L., Davis, C., Kirkman, D., & Zuo, L. 1995, in QSO Absorption Lines, ed. Meylan, G. (Berlin: Springer-Verlag), p. 289.Google Scholar
Womble, D.S., Sargent, W.L.W., & Lyons, R.S. 1996, in Cold gas at High Redshift, eds. Bremer, M., Rottgering, H., van der Werf, P., Carilli, C. (Kluwer), in press.Google Scholar