Atomic transition probabilities for 915 spectral lines of neutral and singly ionized dysprosium are reported. Typical uncertainties are less than +/- 10%. Branching fractions, measured using the 1.0 m Fourier transform spectrometer (FTS) at the National Solar Observatory (NSO) and the 2.0 m FTS at the National Institute of Standards and Technology (NIST), are combined with recently published radiative lifetimes, measured using time-resolved laser induced fluorescence on a slow atomic/ionic beam, to determine these transition probabilities. Reference sets of ArI and ArII branching ratios are used in most of the work reported here to establish a radiometric calibration for the Fourier transform spectra from the NSO. A subset of the lines are also measured using the NIST FTS. Most importantly, an independent radiometric calibration based on standard lamps is used with the NIST FTS. The generally good agreement between the independent measurements provides additional confidence in the radiometric calibration and the accuracy of the measurements.
Journal of Quantitative Spectroscopy and Radiative Transfer