THE INFLUENCE OF INTERACTIONS OF DISTANT GALAXIES ON THEIR NON-THERMAL RADIO EMISSION

Abstract

It has been established that a strong linear correlation exists between the thermal far-infrared (FIR) and non-thermal radio emissions of star-forming galaxies. Recent research on this correlation at high redshifts has revealed that it is evolving as red- shifts increase. This paper explores potential physical factors contributing to this cor- relation’s evolution, with one likely explanation being galaxy interactions. Galaxie’s morphology serves as an indicator of past or ongoing interactions, as irregular galaxy shapes are often the result of collisions or close encounters. To investigate this hypoth- esis, a sample of dusty star-forming galaxies from the COSMOS field, up to a redshift of z = 3.5, was carefully selected. The sample was divided into two subsets based on morphological types: disk and irregular galaxies. The evolution of the correlation with redshift was analyzed separately for each subset. The study did not find any indication of redshift evolution in the FIR-radio correlation for both disk and irregu- lar galaxy subsets. However, the analysis did reveal that irregular galaxies exhibited a lower mean correlation parameter, qFIR, suggesting that they might influence the correlation’s evolution if their prevalence in the sample increases at higher redshifts.