ORT OBSERVATIONS OF THE DAMPED LYMAN-ALPHA SYSTEM TOWARDS PKS-0201+113

Citation
N. Kanekar et Jn. Chengalur, ORT OBSERVATIONS OF THE DAMPED LYMAN-ALPHA SYSTEM TOWARDS PKS-0201+113, Monthly Notices of the Royal Astronomical Society, 292(4), 1997, pp. 831-834
Citations number
15
ISSN journal
00358711
Volume
292
Issue
4
Year of publication
1997
Pages
831 - 834
Database
ISI
SICI code
0035-8711(1997)292:4<831:OOOTDL>2.0.ZU;2-8
Abstract
We report a deep radio search with the Ooty Radio Telescope (ORT) for the redshifted 21-cm absorption line from the damped Lyman a system se en at redshift 3.388 against the quasar PKS 0201 + 113. This is curren tly the most distant system for which a detection of the 21-cm absorpt ion line has been claimed. The present observations have a sensitivity comparable to the earlier ones and detect no statistically significan t absorption. We use the non-detection to place an upper limit of simi lar to 0.011 on the optical depth of the damped Lyman a absorber. This corresponds to a lower limit of similar to 5600K to the spin temperat ure of the system. This is considerably higher than the previous upper limit of similar to 1380 K.