ALMACAL I: First dual-band number counts from a deep and wide ALMA submm survey, free from cosmic variance

Understand

We have exploited ALMA calibration observations to carry out a novel, wide and deep submm survey, ALMACAL.

• These calibration data comprise a large number of observations of calibrator fields in a variety of frequency bands and array configurations.
• Gathering together data acquired during multiple visits to many ALMA calibrators, it is possible to reach noise levels which allow the detection of faint dusty, star-forming galaxies (DSFGs) over a significant area.
• In this paper we outline our survey strategy and report the first results.