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HI 21cm absoprtion in two low redshift damped Ly-alpha systems

W. Lane·A. Smette·F. Briggs·S. Rao·D. Turnshek·G. Meylan
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Abstract

We report the discovery of two low redshift HI 21cm absorbers, one at z = 0.2212 towards the z_{em} = 0.630 quasar OI 363 (B0738+313), and the other at z = 0.3127 towards PKS B1127-145 (z_{em} = 1.187). Both were found during a survey of MgII selected systems at redshifts 0.2 < z < 1 using the new UHF-high system at the Westerbork Synthesis Radio Telescope (WSRT). New HST/FOS observations also identify both systems as damped Ly-alpha (DLa) absorbers. By comparing the column density from the DLa line with that from the HI 21cm line, we calculate the spin temperature, and find that T_s is approximately 1000 K for both of these low redshift absorbers. We briefly discuss some implications of this result.

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W. Lane, A. Smette, F. Briggs, S. Rao, D. Turnshek, G. Meylan. 1998-03-20. HI 21cm absoprtion in two low redshift damped Ly-alpha systems. https://doi.org/10.1086/300422

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