Stellar population of the interacting galaxies M51

TL;DR

This study analyzes the stellar populations in the interacting galaxy system M51 using Hubble data, revealing the distribution, metallicity, and the composition of interaction-induced features like feathers.

Contribution

It provides detailed stellar photometry and metallicity measurements, and compares observed star distributions with models, offering new insights into the effects of galaxy interactions.

Findings

Red supergiant metallicity varies with radius.

Star distribution in NGC5194 aligns with spiral galaxy models.

Feathers mainly consist of intermediate-age stars.

Abstract

Stellar photometry of about one million stars in the system of the interacting galaxies M51 (NGC5194/NGC5195) has been carried out on the basis of the ACS/WFC images of the Hubble Space telescope. The distance to the system has been determined by TRGB method and metallicity of red supergiants along the NGC5194 radius has been measured. A comparison of the spacial distribution of stars in the main galaxy NGC5194 with our empirical model of spiral galaxies showed their similarity, in spite of interaction in system M51. It has been discovered that the "feathers", arising as a result of the interaction of galaxies, mainly consist of stars of intermediate age.