2026-10-12T17:02:35Z https://www.scidb.cn/oai

10.57760/sciencedb.40938 2026-06-29T15:53:10Z

2026-06-29 南山26米射电望远镜Planck早期冷核H₂CO 6 cm吸收线观测数据集 doi:10.57760/sciencedb.40938 en This dataset contains H₂CO  4.8 GHz, approximately 6 cm, absorption-line observations toward 73 Planck Early Cold Cores obtained with the Nanshan 26-m radio telescope. The observations were conducted between October 2022 and December 2024 and include single-pointing observations of all 73 targets, together with mapping observations of four high signal-to-noise core regions.The dataset includes source names, equatorial and Galactic coordinates, H₂CO spectra, central velocities, integrated intensities, peak brightness temperatures, line widths, rms noise levels, and spectral fitting parameters. For sources with resolved hyperfine structure, excitation temperatures, optical depths, and H₂CO column densities are also provided. Thermal and non-thermal velocity dispersions, sound speeds, and Mach numbers derived using complementary NH₃ kinetic-temperature measurements are included where available.H₂CO absorption was detected in 51 of the 73 sources, corresponding to a detection rate of 69.9%, and 24 sources exhibit resolved hyperfine-structure components. The dataset can be used to investigate the physical conditions, excitation properties, turbulence, kinematics, and early gravitational evolution of cold molecular gas in Planck Early Cold Cores, thereby providing observational constraints on the initial conditions of star formation. Planck Early Cold Cores; H₂CO; 6 cm absorption line; Hyperfine structure ye er na er · yi ma na li PUBLIC https://creativecommons.org/licenses/by/4.0/ dataset Science Data Bank