HIDES spectroscopy of bright detached eclipsing binaries from the Kepler field – III. Spectral analysis, updated parameters and new systems

We present the latest results of our spectroscopic observations and refined modelling of a sample of detached eclipsing binaries, selected from the Kepler Eclipsing Binary Catalog, that are also double-lined spectroscopic binaries (SB2s). New high-resolution spectra obtained with the IIIgh-Dispersion Echelle Spectrograph (HIDES), attached to the 1.88-m telescope of the Okayama Astrophysical Observatory, have supplemented the previous observations. This has allowed us to improve the physical parameters of some systems, and to characterize three previously omitted objects. All the obtained radial velocities were combined with Kepler photometry, in order to derive a full set of orbital and physical parameters. Ten out of eleven SB2s have their component spectra tomographically disentangled, and spectral analysis was performed with ISPEC, in order to derive the effective temperatures of components and the metallicities of the systems. By comparing our results with theoretical models, we assess the age and evolutionary status of the studied objects. We find a good match to all systems but one. We have derived distances from the parameters determined in this way, and we compare them with those from the Gaia Data Release 2. For systems previously studied by other authors, our new results lead to better consistency between observations and models.