Mg II Detection in the Lyman Alpha Forest: Metal Rich Cloud or LSB/Dwarf Galaxy?

Abstract

We report the detection of Mg II absorption in two Lyman alpha forest clouds along the line of sight to PKS 0454+039. These clouds, at redshifts z=0.6248 and z=0.9315, respectively, also have strong Fe II absorption. We present results on the z=0.9315 cloud. The upper limit on log N(HI) is 16.5 cm^-2. Based upon UV background photoionization models, we infer that the cloud has super-solar metallicity. Photoionization by a late-type stellar population is ruled out.

2 pages, 1 EPS figures, conf_iap.sty To appear in 13th IAP Workshop (1-5 July 1997) "Evolution of the Intergalactic Medium from QSO Absorption Line Systems" eds. P. Petitjean & S. Charlot