KDG 64: a large dwarf spheroidal or a small ultradiffuse satellite of Messier 81
In: Monthly Notices of the Royal Astronomical Society, Volume 520, Issue 4, pp.6312-6321, 2023; (2022)
Online
report
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 ultradiffuse 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.
Comment: 10 pages, 5 figures, published in MNRAS
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KDG 64: a large dwarf spheroidal or a small ultradiffuse satellite of Messier 81
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Autor/in / Beteiligte Person: | Afanasiev, Anton V. ; Chilingarian, Igor V. ; Grishin, Kirill A. ; Makarov, Dmitry ; Makarova, Lidia ; Fabricant, Daniel ; Caldwell, Nelson ; Moran, Sean |
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Quelle: | Monthly Notices of the Royal Astronomical Society, Volume 520, Issue 4, pp.6312-6321, 2023; (2022) |
Veröffentlichung: | 2022 |
Medientyp: | report |
DOI: | 10.1093/mnras/stad559 |
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