Ongoing hierarchical massive cluster assembly: the LISCA II structure in the Perseus complex

A. Della Croce; E. Dalessandro; A. Livernois; E. Vesperini; C. Fanelli; L. Origlia; M. Bellazzini; E. Oliva; N. Sanna; A. L. Varri

doi:10.1051/0004-6361/202346095

Ongoing hierarchical massive cluster assembly: the LISCA II structure in the Perseus complex

A. Della Croce^*, E. Dalessandro, A. Livernois, E. Vesperini, C. Fanelli, L. Origlia, M. Bellazzini, E. Oliva, N. Sanna, A. L. Varri

^*Corresponding author for this work

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract

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

Original language	English
Article number	A93
Pages (from-to)	1-20
Number of pages	20
Journal	Astronomy and Astrophysics
Volume	674
DOIs	https://doi.org/10.1051/0004-6361/202346095
Publication status	Published - 6 Jun 2023

Keywords / Materials (for Non-textual outputs)

galaxies: star clusters
general / open clusters and associations
general / astrometry / stars
kinematics and dynamics / stars: formation

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10.1051/0004-6361/202346095Licence: Creative Commons: Attribution (CC-BY)

https://arxiv.org/abs/2303.15501Licence: Creative Commons: Attribution (CC-BY)

Rethinking the dynamical paradigm of low-mass stellar systems
Varri, A. L. (Principal Investigator)
Other
1/05/19 → 30/04/23
Project: Research

Cite this

@article{429bd9bd3fc44bdbbeac796c68bb4466,

title = "Ongoing hierarchical massive cluster assembly: the LISCA II structure in the Perseus complex",

abstract = "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{\textquoteright}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 ",

keywords = "galaxies: star clusters, general / open clusters and associations, general / astrometry / stars, kinematics and dynamics / stars: formation",

author = "Croce, \{A. Della\} and E. Dalessandro and A. Livernois and E. Vesperini and C. Fanelli and L. Origlia and M. Bellazzini and E. Oliva and N. Sanna and Varri, \{A. L.\}",

note = "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: {\textcopyright} The Authors 2023.",

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day = "6",

doi = "10.1051/0004-6361/202346095",

language = "English",

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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 -

Ongoing hierarchical massive cluster assembly: the LISCA II structure in the Perseus complex

Abstract

Keywords / Materials (for Non-textual outputs)

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Rethinking the dynamical paradigm of low-mass stellar systems

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