A Comprehensive Power Spectral Density Analysis of Astronomical Time Series. I. The Fermi-LAT Gamma-Ray Light Curves of Selected Blazars

M.T. acknowledges support by the Polish National Science Center (NSC) through OPUS grant No. 2017/25/B/ST9/01208. The work of N.Z. is supported by the South African Research Chairs Initiative (grant No. 64789) of the Department of Science and Innovation and the National Research Foundation27 of South Africa. V.M. is supported by NSC grant No. 2016/22/E/ST9/00061. J.P.-G. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709) and from Spanish public funds for research under project ESP2017-87676-C5-5-R.