Orbital and physical parameters of eclipsing binaries from the ASAS catalogue - V. Investigation of subgiants and giants: the case of ASAS J010538-8003.7, ASAS J182510-2435.5 and V1980 Sgr

We present absolute physical and orbital parameters for three double-lined detached eclipsing binary systems from the All Sky Automated Survey (ASAS) catalogue with subgiant and giant components. These parameters were derived from archival V-band ASAS photometry and new radial velocities. The radial velocities were calculated from high-quality optical spectra we obtained with the 8.2-m Subaru/HDS (High Dispersion Spectrograph), ESO (European Southern Observatory) 3.6 m/HARPS (High Accuracy Radial velocity Planet Searcher), 1.9m Radcliffe/GIRAFFE, Cerro Tololo Inter-American Observatory (CTIO) 1.5m/CHIRON and 1.2m Euler/CORALIE using the two-dimensional cross-correlation technique (TODCOR) and synthetic template spectra chosen for every system separately as references. The physical and orbital parameters of the systems were derived with the phoebe and jktebop codes. We checked the evolutionary status of the systems with several sets of isochrones and determined distances for each system. The derived uncertainties for individual masses of ASAS J010538-8003.7, ASAS J182510-2435.5 and V1980 Sgr components vary from 0.7 per cent to 3.6 per cent while the radii are in the range 1 to 24 per cent. For all of the investigated systems such a detailed orbital and physical analysis is presented for the first time.