Early-Type (E, S0) Galaxies in the Catalog of Isolated Galaxies (KIG)

We use the data of modern digital sky surveys (PanSTARRS-1, SDSS) combined with H I-line and far ultraviolet (GALEX) surveys to reclassify 165 early-type galaxies from the Catalog of Isolated Galaxies (KIG). As a result, the number of E- and S0-type galaxies reduced to 91. Our search for companions of early-type KIG galaxies revealed 90 companions around 45 host galaxies with line-of-sight velocity differences $$\left| {dV} \right| < 500$$ km s–1 and linear projected separations $${{R}_{p}} < 750$$ kpc. We found no appreciable differences in either integrated luminosity or color of galaxies associated with the presence or absence of close neighbors. We found a characteristic orbital mass-to-luminosity ratio for 26 systems “KIG galaxy–companion” to be $${{{{M}_{ \odot }}} \mathord{\left/ {\vphantom {{{{M}_{ \odot }}} {{{L}_{K}}}}} \right. \kern-0em} {{{L}_{K}}}} = {{(74 \pm 26){{M}_{ \odot }}} \mathord{\left/ {\vphantom {{(74 \pm 26){{M}_{ \odot }}} {{{L}_{ \odot }}}}} \right. \kern-0em} {{{L}_{ \odot }}}}$$ , which is consistent with the $${{{{M}_{{{\text{orb}}}}}} \mathord{\left/ {\vphantom {{{{M}_{{{\text{orb}}}}}} {{{L}_{K}}}}} \right. \kern-0em} {{{L}_{K}}}}$$ estimates for early-type isolated galaxies in the 2MIG catalog ( $${{63{{M}_{ \odot }}} \mathord{\left/ {\vphantom {{63{{M}_{ \odot }}} {{{L}_{ \odot }}}}} \right. \kern-0em} {{{L}_{ \odot }}}}$$ ), and also with the $${{{{M}_{{{\text{orb}}}}}} \mathord{\left/ {\vphantom {{{{M}_{{{\text{orb}}}}}} {{{L}_{K}}}}} \right. \kern-0em} {{{L}_{K}}}}$$ estimates for E- and S0-type galaxies in the Local Volume: $$38 \pm 22$$ (NGC 3115), $$82 \pm 26$$ (NGC 5128), $$65 \pm 20$$ (NGC 4594). The high halo-to-stellar mass ratio for E- and S0-type galaxies compared to the average $${{(20 \pm 3){{M}_{ \odot }}} \mathord{\left/ {\vphantom {{(20 \pm 3){{M}_{ \odot }}} {{{L}_{ \odot }}}}} \right. \kern-0em} {{{L}_{ \odot }}}}$$ ratio for bulgeless spiral galaxies is indicative of a significant difference between the dynamic evolution of early- and late-type galaxies.