Investigation of QSO spectra having measured Lα from GALEX FUV

Active Galactic Nuclei, especially quasars, have not been thoroughly investigated in far UV range. There are few observations in this range, and most of this range is available for objects with high redshifts, whose UV range is shifted to the optical one. But on the other hand, there is GALAXY Evolution Explorer (GALEX) space UV telescope catalog, where 82,992,086 near-UV (NUV, 1750–2800 ˚A) and far-UV (FUV, 1350–1750 ˚A) flux measurements in UV bands are available. In order to find a connection between the fluxes of two of the most important emission lines, λ5007 (OIII) and λ1216 (Lα) in the spectra of quasars, we created a sample of quasars with measured Lα. For this, we took the Milliquas 2023 catalog, which contains 1,021,800 objects. From these objects, we selected those having redshifts lying between 0.15 < z < 0.40, so that Lα spectral line is located in GALEX FUV window. As a result, we have 42,150 objects. These sources were identified with SDSS DR16 and GALEX DR6+DR7, and as a result we have 11,697 identifications which have data from both SDSS and GALEX. Using a pilot survey (for 177 objects), we found a preliminary connection between Lα and OIII lines.