Large-scale surveys with the Arecibo multibeam system

The Arecibo 305 m antenna is the largest filled-aperture radio telescope in the world. As such, it has extraordinary potential for high-sensitivity surveys. A new 7-element, 1225-1525 MHz, dual-polarization focal plane array receiver was installed in April 2004. The Arecibo L-band Focal Plane Array (ALFA) increases mapping speeds and so enables large-scale surveys for galactic astronomy, including HI and recombination lines and continuum, extragalactic astronomy using HI, and pulsars. We discuss some key characteristics of the new systems and the surveys that are being proposed. Additional information on ALFA and associated scientific consortia is available at http://alfa.naic.edu/.