A deep view into the nucleus of the Sagittarius dwarf spheroidal galaxy: M54

Author(s)

M. Alfaro-Cuello, N. Kacharov, N. Neumayer, A. Mastrobuono-Battisti, N. Lützgendorf, Anil C. Seth, T. Böker, S. Kamann, R. Leaman, G. van de Ven, P. Bianchini, L. L. Watkins, M. Lyubenova

Abstract

Nuclear star clusters hosted by dwarf galaxies exhibit similar

characteristics to high-mass, metal complex globular clusters. This type

of globular clusters could, therefore, be former nuclei from accreted

galaxies. M54 resides in the photometric center of the Sagittarius dwarf

galaxy, at a distance where resolving stars is possible. M54 offers the

opportunity to study a nucleus before the stripping of their host by the

tidal field effects of the Milky Way. We use a MUSE data set to perform

a detailed analysis of over 6600 stars. We characterize the stars by

metallicity, age, and kinematics, identifying the presence of three

stellar populations: a young metal-rich (YMR), an intermediate-age

metal-rich (IMR), and an old metal-poor (OMP). The evidence suggests

that the OMP population is the result of accretion of globular clusters

in the center of the host, while the YMR population was born in-situ in

the center of the OMP population.

Organisation(s)

Department of Astrophysics

External organisation(s)

Max-Planck-Institut für Astronomie, European Space Agency (ESA), Baltimore, University of Utah, Liverpool John Moores University (LJMU), Université de Strasbourg, European Southern Observatory (Germany)

Journal

Proceedings of the International Astronomical Union

Volume

14

Pages

47-50

No. of pages

4

DOI

https://doi.org/10.1017/S1743921319007907

Publication date

03-2020

Austrian Fields of Science 2012

103003 Astronomy, 103004 Astrophysics

Keywords

ASJC Scopus subject areas

Astronomy and Astrophysics, Space and Planetary Science

Portal url

https://ucris.univie.ac.at/portal/en/publications/a-deep-view-into-the-nucleus-of-the-sagittarius-dwarf-spheroidal-galaxy-m54(9916a1ad-0841-43b5-bc3a-2e12672f2ccc).html