Determination of Redshifts for Selected IVS Sources. I

TL;DR

This study reports spectroscopic redshift measurements for seven IVS radio sources, aiding in their identification and contributing to refining cosmological parameters through improved distance estimates.

Contribution

It provides the first spectroscopic redshifts for seven IVS sources, enhancing source identification and supporting cosmological model refinement.

Findings

Reliable identification of four sources based on spectra and redshifts

Three sources require further observational study

Redshift data will improve cosmological parameter estimates

Abstract

From observations with the 6-m BTA telescope at SAO RAS, we have determined spectroscopic redshifts of seven optical objects whose coordinates coincide with those of radio sources from the list of IVS (International VLBI Service for Geodesy and Astrometry). When compared to radio data, the obtained spectra and redshifts provide evidence for reliable identification of four observed objects; the other three require further study. The distances to the sources derived from our measurements will make it possible to refine the current estimates for parameters of cosmological models based on proper motions of these objects, which are determined from geodetic VLBI observations.