FAST Ultra-Deep Survey: Data Release for FUDS0

Abstract We have used the Five-hundred-meter Aperture Spherical radio Telescope (FAST) to conduct a blind ultradeep survey for neutral hydrogen (H i ). We present the complete results from the first of six fields (FUDS0). These observations of 95 hr allowed us to achieve a high-sensitivity (∼50 μ Jy beam −1 ) and a high-frequency resolution (22.9 kHz) over an area of 0.72 deg 2 . We detected 128 galaxies in H i distributed over the redshift range of 0 6.67 ≤ log ( M H I / h 70 − 2 M ⊙ ) ≤ 10.92 , and three faint high-velocity clouds, with a peak column density of N H i ≤ 3.1 × 10 17 cm −2 . Of the galaxies, 95 are new detections and six have z > 0.38, where no unlensed H i emission has previously been directly detected. Estimates of completeness and reliability are presented for the catalog. The consistency of continuum and H i flux estimates with the NRAO VLA Sky Survey and the Arecibo Ultra-Deep Survey, respectively, confirms the accuracy of the calibration method and data reduction pipeline developed for the full FAST Ultra-Deep Survey.