Context. Absorption lines of H_(2)and HD molecules observed at high redshift in the line of sight towards quasars are a test ground to search for variation of the proton-to-electron mass ratio μ . For this purpose, results from astronomical observations are compared with a compilation of molecular data of the highest accuracy, obtained in laboratory studies as well as in first-principles calculations. Aims. A comprehensive line list is compiled for H_(2)and HD absorption lines in the Lyman ( B ~(1)Σ_( u )~(+)? X ~(1)Σ_( g )~(+)) and Werner ( C ~(1)Π_( u )? X ~(1)Σ_( g )~(+)) band systems up to the Lyman cutoff at 912 ?. Molecular parameters listed for each line i are the transition wavelength λ _( i ), the line oscillator strength f _( i ), the radiative damping parameter of the excited state Γ_( i ), and the sensitivity coefficient K _( i )for a variation of the proton-to-electron mass ratio. Methods. The transition wavelengths λ _( i )for the H_(2)and HD molecules are determined by a variety of advanced high-precision spectroscopic experiments involving narrowband vacuum ultraviolet lasers, Fourier-transform spectrometers, and synchrotron radiation sources. Results for the line oscillator strengths f _( i ), damping parameters Γ_( i ), and sensitivity coefficients K _( i )are obtained in theoretical quantum chemical calculations. Results. A new list of molecular data is compiled for future analyses of cold clouds of hydrogen absorbers, specifically for studies of μ -variation from quasar data. The list is applied in a refit of quasar absorption spectra of B0642–5038 and J1237+0647 yielding constraints on a variation of the proton-to-electron mass ratio Δ μ / μ consistent with previous analyses.
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