TY - JOUR
T1 - Ongoing hierarchical massive cluster assembly: the LISCA II structure in the Perseus complex
AU - Croce, A. Della
AU - Dalessandro, E.
AU - Livernois, A.
AU - Vesperini, E.
AU - Fanelli, C.
AU - Origlia, L.
AU - Bellazzini, M.
AU - Oliva, E.
AU - Sanna, N.
AU - Varri, A. L.
N1 - 21 pages, 24 figures, 1 table; accepted for publication in A&A
Funding Information:
The authors thank the anonymous referee for the careful reading of the paper and the useful comments and suggestions. A.D.C., E.D. and L.O. acknowledge financial support from the project Light-on-Dark granted by MIUR through PRIN2017-2017K7REXT contract. E.D. acknowledges support from the Indiana University Institute for Advanced Study through the Visiting Fellowship program. This work uses data from the European Space Agency (ESA) space mission Gaia. Gaia data are being processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC is provided by national institutions, in particular, the institutions participating in the Gaia Multi-Lateral Agreement (MLA).
Publisher Copyright:
© The Authors 2023.
PY - 2023/6/6
Y1 - 2023/6/6
N2 - We report on the identification of a massive (∼105 M⊙) substructured stellar system in the Galactic Perseus complex likely undergoing hierarchical cluster assembly. This system comprises nine star clusters (including the well-known clusters NGC 654 and NGC 663) and an extended and low-density stellar halo. Gaia-DR3 and available spectroscopic data show that all its components are physically consistent in 6D phase-space (position, parallax, and 3D motion), and homogeneous in age (14–44 Myr) and chemical content (half-solar metallicity). In addition, the system’s global stellar density distribution is that of typical star clusters and shows clear evidence of mass segregation. We find that the hierarchical structure is mostly contracting toward the center with a speed of up to ≃4 − 5 km s−1, while the innermost regions expand at a lower rate (about ≃1 km s−1) and are dominated by random motions. Interestingly, this pattern is dominated by the kinematics of massive stars, while low-mass stars (M
AB - We report on the identification of a massive (∼105 M⊙) substructured stellar system in the Galactic Perseus complex likely undergoing hierarchical cluster assembly. This system comprises nine star clusters (including the well-known clusters NGC 654 and NGC 663) and an extended and low-density stellar halo. Gaia-DR3 and available spectroscopic data show that all its components are physically consistent in 6D phase-space (position, parallax, and 3D motion), and homogeneous in age (14–44 Myr) and chemical content (half-solar metallicity). In addition, the system’s global stellar density distribution is that of typical star clusters and shows clear evidence of mass segregation. We find that the hierarchical structure is mostly contracting toward the center with a speed of up to ≃4 − 5 km s−1, while the innermost regions expand at a lower rate (about ≃1 km s−1) and are dominated by random motions. Interestingly, this pattern is dominated by the kinematics of massive stars, while low-mass stars (M
KW - galaxies: star clusters
KW - general / open clusters and associations
KW - general / astrometry / stars
KW - kinematics and dynamics / stars: formation
U2 - 10.1051/0004-6361/202346095
DO - 10.1051/0004-6361/202346095
M3 - Article
SN - 0004-6361
VL - 674
SP - 1
EP - 20
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A93
ER -