The Commensal Radio Astronomy FasT Survey (CRAFTS; Li et al. 2018) is one of the Five-hundred-meter Aperture Spherical radio Telescope (FAST) key projects. CRAFTS simultaneously records wide-band spectral line data, narrow-band spectral line data, and high temporal resolution time-domain data, enabling diverse scientific objectives. The wide-band spectral line data cover a spectral window in the 1.0–1.5 GHz frequency range with a frequency resolution of 7.6 kHz. Its primary scientific objectives include the study of extra-galactic neutral hydrogen (HI), cosmic large-scale structures, Galactic radio recombination lines, and fast radio bursts (FRB). By simultaneously conducting HI mapping and FRB searches, CRAFTS has significantly enhanced FAST's survey efficiency.
Having operated for five years since 2020, CRAFTS has completed 27% of its planned sky coverage. With the preliminary processing of its wide-band spectral line data nearing completion, the CRAFTS team has pre-released the data cube to facilitate scientific research in the aforementioned research fields. This pre-release, launched on April 1, 2025 via ScienceDB (Science Data Bank, a public data repository for scientific research), initially includes 14 observational sessions totaling 70 hours. Data coverage will expand progressively over the next few weeks, with concurrent quality improvements. Due to radio interference in the early data sets, this pre-release only includes approximately 900 hours of data collected from July 31, 2021 to January 30, 2025 (frequency range of 1323 MHz to 1419 MHz), yielding ~1.5 TB calibrated data. Remaining data will be fully released in subsequent phases. All datasets are freely accessible without collaboration requirements.
CRAFTS is led by Professor Di Li (Tsinghua University/NAOC), with wide-band data processing led by NAOC, in partnership with Zhejiang Lab and Guizhou Normal University.
Release web-page: https://hiverse.zero2x.org/wide
Data link: https://doi.org/10.57760/sciencedb.Fastro.00024
Sky coverage of the CRAFTS observations. This pre-release includes 14 observational sessions totaling 70 hours. Data within the blue regions will be released incrementally over the next few weeks. The gray regions are excluded from this release and are anticipated to be fully released in the next official data release. Zenith Angle (ZA) refers to the angle between the telescope’s pointing direction and the zenith (directly overhead, at an elevation of 90°). FAST can observe up to a ZA of 40° (two black parallels), and keep its efficiency within 26.4° (two red parallels).
References:
Li, et al. 2018, IEEE Microwave Magazine, Vol 19, Issue 3, pp112-119