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Description
The Arecibo L-band Feed Array Zone of Avoidance (ALFAZOA) Shallow Survey is a blind H I survey of the extragalactic sky behind the northern Milky Way conducted with the ALFA receiver on the 305 m Arecibo Radio Telescope. ALFAZOA Shallow covered 900 square degrees at full sensitivity from 30{deg}=<l=<75{deg} and |b|=<10{deg} and an additional 460 square degrees at limited sensitivity at latitudes up to 20{deg}. It has an rms sensitivity of 5-7 mJy and a velocity resolution of 9-20.6 km/s, and detected 403 galaxies out to a recessional velocity of 12000 km/s, with an angular resolution of 3.4' and a positional accuracy between 0.2' and 1.7'. The survey is complete above an integrated line flux of F_HI_=2.0 Jy km/s for half the survey, and above F_HI_= 2.8 Jy km/s for the other half. Of the ALFAZOA H I detections, 43% have at least one possible optical/near-infrared counterpart in the literature, and an additional 16% have counterparts that only included previous H I measurements. There are fewer counterparts in regions of high extinction and for galaxies with lower H I mass. Comparing the results of the survey to the predictions of Erdogdu et al. (2006MNRAS.373...45E), and using their nomenclature, ALFAZOA confirms the position and extent in the ZOA of the C7, C{zeta}, Pegasus, Corona Borealis, and Delphinus structures, but not of the Cygnus void. Two new structures are identified, both connected to the C7 overdensity; one extends to 35{deg}, and the other crosses the ZOA.
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