... A2525 Date Received: 2009-Sep-30 01:15:50 Technical Page Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Minimum Useful Time: Prop osal Title: ABSTRACT: Regular Astronomy Spectroscopy Extragalactic 160 Hours 1 hour Do the fundamental constants change with time ? We propose to use the Arecibo L-band receiver to obtain deep, high resolution spectra in the redshifted 18cm satellite OH lines from the z = 0.247 source, PKS1413+135. ...

... 2.3 Data acquisition Spectra generated by the Multibeam correlator contain the usual structure seen in spectra from other H i instruments: a bandpass spectrum which is the sum of the sky , ground and receiver temperatures multiplied by the product of the filters in the receiver chain; superimposed on this is a noise ... Note also that sources extended much beyond ,40 arcmin can be imaged poorly in HIPASS images because of the bandpass sidelobe effect described in Section 3.3. ...