Stellar content of the interacting galaxies IC 1727 and NGC 672

作者：Tikhonov N A^*; Galazutdinova O A; Lebedev V S

来源：Astronomy Letters, 2014, 40(1): 11-21.

DOI：10.1134/S106377371401006X

• galactic photometry
• stellar content of galaxies
• interacting galaxies
• star formation in galaxies

Based on archival Hubble Space Telescope ACS/WFC images, we have performed stellar photometry for an isolated pair of interacting galaxies, IC 1727 and NGC 672, and constructed their Hertzsprung-Russell diagrams. The galaxy IC 1727 exhibits a strong asymmetry in the apparent distribution of young stars. The distribution of old stars is smoother and less asymmetric. In the galaxy NGC672, there is no noticeable asymmetry in the distribution of stars of different ages. Based on the TRGB method, we have determined an accurate distance to each galaxy for the first time: D = 7.14 +/- 0.10 Mpc for IC 1727 and D = 7.22 +/- 0.10 Mpc for NGC 672, confirming that these galaxies are closely spaced. The luminosity functions of red supergiants and peripheral AGB stars in both galaxies have positionally coincident local maxima, suggesting the simultaneous enhancement of star formation in the two galaxies occurred in the intervals 20-30 and 450-700 Myr ago. The results obtained point to an enhancement of star formation processes in the interacting galaxies.

• 出版日期2014-1