Proposal Identification No.: A2133 Date Received: 2008-Jun-08 19:16:09 Technical Page Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Prop osal Title: ABSTRACT: Large Astronomy Spectroscopy Extragalactic 980 Hours The Alfa Ultra-Deep Survey: Deep HI Observations at 0<z<0.16 The improved spatial and spectral survey capabilities available with ALFA opened a new era of high sensitivity observations for the Arecibo telescope. ... X Part of the observing run. ...

... 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. ...