... Things to think about ­ INTMIT, deconvolution Lister Staveley-Smith ­ X-ALFA March 15, 2003 1 HIPASS Bright Galaxy Catalog (BGC) Koribalski et al. ... Arecibo beam Parkes beam HIPASS spectrum HIPASS J0620-57 = ESO161-G001/NGC 2222/NGC 2221 (ATCA observation) Lister Staveley-Smith ­ X-ALFA March 15, 2003 8 The ALFA advantage ­ an example ! Cosmic variance for HIPASS BGC dwarfs #10 Mpc cells Dwarf galaxies Lister Staveley-Smith ­ X-ALFA March 15, 2003 9 Cosmic Variance in HIPASS BGC Zwaan et al. ...

... 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. ...