2022ApJS..259...47L

This paper reports computational results on hydrogen Lyman β, γ, and Balmer β spectral lines in the presence of parallel magnetic and electric fields. A two-dimensional B-spline approach is adopted in the current calculations. This approach was originally developed to treat high-lying states but was found to be also effective for low-lying states. Wavelengths and oscillator strengths are presented for a total of 31 transitions in magnetic and electric fields with field strengths ranging, respectively, from 23.5 to 2350 MG and from 0 to 10⁸ V m^–1. These spectral data are compared to available results from other theoretical methods, and good agreement is clearly visible. Our calculations show that in the scope of field strengths we are concerned with, Lyman β and γ spectral lines lie in the ultraviolet region, while the Balmer β lines lie in the ultraviolet and visible-light regions. Furthermore, Zeeman spectral lines related to atomic states in the n = 4 manifold may be blue- or redshifted by a strong electric field, dependent on the transitions as well as on magnetic field strengths. Atomic spectral data of the 31 transitions listed are applicable for modeling discrete spectra of magnetic white dwarfs when a strong electric field exists in the hydrogen-dominated atmospheres of these celestial objects.