An Update on Archeops: Flights and Data Products

Archeops is a balloon-borne instrument dedicated to measuring cosmic microwave background (CMB) temperature anisotropies at high angular resolution (∼ 8 arcminutes) over a large fraction (∼ 30%) of the sky in the millimetre domain. The general design is based on Planck High Frequency Instrument (HFI) technology. Bolometers cooled to 0.1 K scan the sky in total power mode along large circles at constant elevation. Archeops is designed to observe a complete annulus on the sky covering all right ascensions between about 25 and 55 degrees during the course of a 24-hour Arctic-night balloon flight, in four frequency bands centered at 143, 217, 353 and 545 GHz. We describe the Archeops flights and the data products obtained during the three successful flights from Trapani (Sicily) to Spain in July 1999, and from Kiruna (Sweden) to Russia in January 2001 and February 2002. We discuss present Archeops results and the future use of Archeops data.