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The z = 0.8596 damped Ly-alpha absorbing galaxy toward PKS 0454+039We present Hubble Space Telescope (HST) and ground-based data on the Z(sub abs) = 0.8596 metal-line absorption system along the line of sight to PKS 0454+0356. The system is a moderate-redshift damped Ly-alpha system, with N(H I) = (5.7 +/- 0.3) x 10(exp 20)/sq cm as measured from the Faint Object Spectrograph (FOS) spectrum. We also present ground-based images which we use to identify the galaxy which most probably gives rise to the damped system; the most likely candidate is relatively underluminous by QSO absorber standards M(sub B) approximately -19.0 for A(sub 0) = 0.5 and H(sub 0) = 50 km/s/Mpc) and lies approximately 8.5/h kpc in projection from the QSO sight line. Ground-based measurements of Zn II, Cr II, and Fe II absorption lines from this system allow us to infer abundances of (Zn/H) = -1.1, (Cr/H) = -1.2, and (Fe/H) = -1.2 indicating overall metallicity similar to damped systems at z is greater than 2, and that the depletion of Cr and Fe onto dust grains may be even less important than in many of the high-redshift systems of comparable metallicity. Limits previously placed on the 21 cm optical depth in the z = 0.8596 system, together with our new N(H I) measurement, suggest a very high spin temperature for the H I, T(sub s) is greater than 580 K.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Steidel, Charles C. (MIT, Cambridge, MA United States)
Bowen, David V. (Space Telescope Science Inst. Baltimore, MD, Us, United States)
Blades, J. Chris (Space Telescope Science Inst. Baltimore, MD, Us, United States)
Dickenson, Mark (Space Telescope Science Inst. Baltimore, MD, Us, United States)
Date Acquired
August 16, 2013
Publication Date
February 20, 1995
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 440
Issue: 2
ISSN: 0004-637X
Subject Category
Distribution Limits