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KDG 64: a large dwarf spheroidal or a small ultra-diffuse satellite of Messier 81статья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Afanasiev Anton V., Chilingarian Igor V., Grishin Kirill A., Makarov Dmitry, Makarova Lidia, Fabricant Daniel, Nelson Caldwell, Sean Moran
- Журнал: Monthly Notices of the Royal Astronomical Society
- Том: 520
- Номер: 4
- Год издания: 2023
- Издательство: Oxford Journals, Oxford University Press
- Местоположение издательства: Oxford, UK, England
- Первая страница: 6312
- Последняя страница: 6321
- DOI: 10.1093/mnras/stad559
- Аннотация: Low-mass early-type galaxies, including dwarf spheroidals (dSph) and brighter dwarf ellipticals (dE), dominate the galaxy population in groups and clusters. Recently, an additional early-type population of more extended ultra-diffuse galaxies (UDGs) has been identified, sparking a discussion on the potential morphological and evolutionary connections between the three classifications. Here we present the first measurements of spatially resolved stellar kinematics from deep integrated-light spectra of KDG 64 (UGC 5442), a large dSph galaxy in the M 81 group. From these data we infer stellar population properties and dark matter halo parameters using Jeans dynamical modelling. We find an old, metal-poor stellar population with no young stars and a dark matter mass fraction of ∼90 per cent within the half-light radius. These properties and the position of KDG 64 on the Fundamental Plane indicate that it is a local analogue of smaller UDGs in the Coma and Virgo clusters and is probably a transitional dSph-UDG object. Its evolutionary path cannot be uniquely established from the existing data, but we argue that supernovae feedback and tidal heating played key roles in shaping KDG 64.
- Добавил в систему: Афанасьев Антон Валериевич