A search for high-redshift molecular absorption lines towards millimetre-loud, optically faint quasars |
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| Authors: | M T Murphy S J Curran J K Webb |
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| Institution: | Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA;School of Physics, University of New South Wales, Sydney, NSW 2052, Australia |
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| Abstract: | We describe initial results of a search for redshifted molecular absorption towards four millimetre-loud, optically faint quasars. A wide frequency bandwidth of up to 23 GHz per quasar was scanned using the Swedish–ESO Submillimetre Telescope at La Silla. Using a search list of commonly detected molecules, we obtained nearly complete redshift coverage up to z abs= 5 . The sensitivity of our data is adequate to have revealed absorption systems with characteristics similar to those seen in the four known redshifted millimetre-band absorption systems, but none were found. Our frequency-scan technique nevertheless demonstrates the value of wide-band correlator instruments for searches such as these. We suggest that a somewhat larger sample of similar observations should lead to the discovery of new millimetre-band absorption systems. |
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| Keywords: | techniques: spectroscopic quasars: absorption lines cosmology: observations |
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