naa a22 4500 51079047X CHVBK 20180411083318.0 cr unu---uuuuu 180411e20130201xx s 000 0 eng 10.1134/S1063773713010027 doi (NATIONALLICENCE)springer-10.1134/S1063773713010027 Stellar subsystems of the young tidal dwarf galaxy Ho IX [Elektronische Daten] [N. Tikhonov, O. Galazutdinova] Based on archival Hubble Space Telescope ACS/WFC images, we have performed stellar photometry for the young tidal dwarf galaxy Ho IX. We have determined that star formation in Ho IX began 110 Myr ago and ended 20 Myr ago. We have identified 20 young star clusters in the galaxy with ages from 25 to 100 Myr. For the main star-forming region of Ho IX along one direction, we have determined the change in the number density of stars with three ages: 30, 50, and 90 Myr. A relation has been found between the ages of stars and the spatial sizes of the subsystem formed by them. This relation can be explained by expansion of the stellar subsystems. Under this assumption, the expansion velocity is 9.8 km s−1 as the age changes from 50 to 90 Myr. Edge-on low-mass late-type galaxies have similar relations between the ages and sizes of their stellar subsystems. Pleiades Publishing, Ltd., 2013 galactic photometry nationallicence stellar composition of galaxies nationallicence thin and thick disks nationallicence Tikhonov N. Special Astrophysical Observatory, Russian Academy of Sciences, 369167, Nizhnii Arkhyz, Karachai-Cherkessian Republic, Russia aut Galazutdinova O. Special Astrophysical Observatory, Russian Academy of Sciences, 369167, Nizhnii Arkhyz, Karachai-Cherkessian Republic, Russia aut Astronomy Letters SP MAIK Nauka/Interperiodica 39/2(2013-02-01), 104-110 1063-7737 39:2<104 2013 39 11443 https://doi.org/10.1134/S1063773713010027 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S1063773713010027 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tikhonov N. Special Astrophysical Observatory, Russian Academy of Sciences, 369167, Nizhnii Arkhyz, Karachai-Cherkessian Republic, Russia aut NATIONALLICENCE 700 1- Galazutdinova O. Special Astrophysical Observatory, Russian Academy of Sciences, 369167, Nizhnii Arkhyz, Karachai-Cherkessian Republic, Russia aut NATIONALLICENCE 773 0- Astronomy Letters SP MAIK Nauka/Interperiodica 39/2(2013-02-01), 104-110 1063-7737 39:2<104 2013 39 11443 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer