A Two-level Radial-velocity Zero-point Calibration for LAMOST MRS with Gaia and APOGEE and a Value-added RV Catalogue

This dataset is the value-added radial-velocity (RV) catalogue accompanying the paper "A Two-level Radial-velocity Zero-point Calibration for LAMOST MRS with Gaia and APOGEE and a Value-added RV Catalogue" (Zhang & Yuan). We provide two-level RV zero-point (RVZP) corrected radial velocities for the LAMOST DR12 v1.1 Medium-Resolution Survey (MRS) blue-arm application sample. The correction combines a spectrograph-exposure term (in (lmjm, planid, spid) units) and a fiber-time term (in (spid, fiberid, time_tag) units), estimated against Gaia DR3 magnitude-colour-corrected RVs and APOGEE DR17 RVs using a weighted-median estimator. For high-S/N spectra, the scatter relative to APOGEE DR17 decreases from ~1.1 km/s to ~0.52 km/s after the full two-level correction.Please cite the accompanying paper when using this catalogue.