ALMA deep field in SSA22: Survey design and source catalog of a 20 arcmin2 survey at 1.1 mm

To search for dust-obscured star-formation activity in the early Universe, it is essential to obtain a deep and wide submillimeter/millimeter map. The advent of the Atacama Large Millimeter/submillimeter Array (ALMA) has enabled us to obtain such maps with sufficiently high spatial resolution to be free from source confusion. We present a new 1.1 mm-wave map obtained by ALMA in the SSA22 field. The field contains a remarkable proto-cluster at z = 3.09; therefore, it is an ideal region to investigate the role of a large-scale cosmic web on dust-obscured star formation. The typical 1 sigma depth of our map is 73 mu Jy beam(-1) with a 0.'' 5 resolution. Combining the present survey with earlier, archived observations, we map an area of 20 arcmin(2) (71 comoving Mpc(2) at z = 3.09). Within the combined survey area we have detected 35 sources at a signal-to-noise ratio (S/N) > 5, with flux densities of S-1.1 mm = 0.43-5.6 mJy, equivalent to star-formation rates of greater than or similar to 100-1000 M-circle dot yr(-1) at z = 3.09, for a Chabrier initial mass function: 17 sources out of 35 are new detections. The cumulative number counts show an excess by a factor of three to five compared to blank fields. The excess suggests enhanced, dust-enshrouded star-formation activity in the proto-cluster on a 10 comoving Mpc scale, indicating accelerated galaxy evolution in this overdense region.