TRGB Distances to Seyfert Galaxies NGC 1068, NGC 3227, NGC 4051, and NGC 4151
Н. А. Тихонов, O. A. Galazutdinova
Abstract
Abstract—We use archive images from the Hubble Space Telescope to perform stellar photometry of four classic Seyfert galaxies: NGC 1068, NGC 3227, NGC 4051, and NGC 4151. We identified the red giants in the images and use the TRGB method for the first time to determine precise distances to these galaxies. The inferred distances—11.14 ± 0.54, 15.33 ± 0.80, 16.48 ± 0.69, and 14.20 ± 0.88 Mpc—make it possible to more accurately estimate the energy emitted by the nuclei of these active galaxies. We determine the distances to the two main galaxies of the NGC 1068 group, NGC 1068 and NGC 1073, (11.14 ± 0.54 and 11.28 ± 0.70 Mpc), allowing the distance to this small group of galaxies to be estimated as $$D = 11.2$$ Mpc. We show that NGC 1087 is located at a distance of $$D = 17.79 \pm 0.83$$ Mpc and therefore does not belong to the NGC 1068 group.