... I note that "Z" plays an important role in what the ALFA surveys will look for: . ... low Z . nearby low mass . ... Arecibo . ... ADBS (Arecibo Dual Beam Survey): Rosenberg & Schneider 2002. ... A few sources with unobvious optical counterparts. ... Coverage wins for volume, but if you do a shallow survey you are sampling only the nearby volume at low masses. ... So need artificial test sources to find completeness. ... Total volume within survey in which source could have been detected. ...
... 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. ...