Searching for nuclear stellar discs in simulations of star cluster mergers

Portaluri, Elisa; Corsini, E. M.; Morelli, L.; Hartmann, Markus; Bontà, E. Dalla; Debattista, Victor P.; Pizzella, A.

doi:10.1093/mnras/stt738

Cited by 12 publications

(13 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The scaling relations between NSCs and their host galaxies suggest a connected evolution, but the formation mechanisms of NSCs are not yet completely understood, and there are two main pathways that are discussed (see review by Neumayer et al 2020). NSCs (and nuclear stellar disks) might form from the subsequent merger of gas-free GCs that spiral inward due to dynamical friction (Tremaine et al 1975;Capuzzo-Dolcetta 1993;Capuzzo-Dolcetta & Miocchi 2008;Agarwal & Milosavljević 2011;Portaluri et al 2013;Arca-Sedda & Capuzzo-Dolcetta 2014). This scenario directly connects NSC formation to the GC population and is usually invoked to explain the presence of metal-poor stellar populations found especially in the NSCs of dwarf galaxies (Rich et al 2017;Alfaro-Cuello et al 2019;Fahrion et al 2020c;Johnston et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Diversity of nuclear star cluster formation mechanisms revealed by their star formation histories

Fahrion,

Lyubenova,

van de Ven

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Nuclear star clusters (NSCs) are the densest stellar systems in the Universe and are found in the centres of all types of galaxies. They are thought to form via mergers of star clusters such as ancient globular clusters (GCs) that spiral to the centre as a result of dynamical friction or through in-situ star formation directly at the galaxy centre. There is evidence that both paths occur, but the relative contribution of either channel and their correlation with galaxy properties are not yet constrained observationally. We aim to derive the dominant NSC formation channel for a sample of 25 nucleated galaxies, mostly in the Fornax galaxy cluster, with stellar masses between M gal ∼ 10 8 and 10 10.5 M and NSC masses between M NSC ∼ 10 5 and 10 8.5 M . Using Multi-Unit Spectroscopic Explorer (MUSE) data from the Fornax 3D survey and the ESO archive, we derive star formation histories, mean ages and metallicities of NSCs, and compare them to the host galaxies. In many low-mass galaxies, the NSCs are significantly more metal-poor than their hosts with properties similar to GCs. In contrast, in the massive galaxies, we find diverse star formation histories and cases of ongoing or recent in-situ star formation. Massive NSCs (> 10 7 M ) occupy a different region in the mass-metallicity diagram than lower mass NSCs and GCs, indicating a different enrichment history. We find a clear transition of the dominant NSC formation channel with both galaxy and NSC mass. We hypothesise that while GC-accretion forms the NSCs of the dwarf galaxies, central star formation is responsible for the efficient mass build up in the most massive NSCs in our sample. At intermediate masses, both channels can contribute. The transition between these formation channels seems to occur at galaxy masses M gal ∼ 10 9 M and NSC masses M NSC ∼ 10 7 M .

show abstract

Section: Introductionmentioning

confidence: 99%

Diversity of nuclear star cluster formation mechanisms revealed by their star formation histories

Fahrion,

Lyubenova,

van de Ven

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Mechanisms that have been proposed for driving gas to small radii in such systems include nested bars (Shlosman, Frank & Begelman 1989), the magnetorotational instability (Milosavljević 2004), and cloud-cloud mergers (Bekki 2007). Agarwal & Milosavljević (2011) proposed that NDs can form out of the debris of infalling star clusters and Portaluri et al (2013) showed that the available photometric and kinematic data are still consistent with this idea. However, detailed modelling (De Lorenzi et al 2013) and comparison to simulations (Hartmann et al 2011) of the kinematics of the nuclear star cluster in NGC 4244 (Seth et al 2008) reveal that gas dissipation had to have played a major role in the formation of its nuclear cluster, indicating that some gas must be able to reach the inner ∼ 10 parsecs.…”

Section: Introductionmentioning

confidence: 99%

The formation of stellar nuclear discs in bar-induced gas inflows

Cole

Debattista

Erwin

et al. 2014

Monthly Notices of the Royal Astronomical Society

Self Cite

123

View full text Add to dashboard Cite

The role of gas in the mass assembly at the nuclei of galaxies is still subject to some uncertainty. Stellar nuclear discs bridge the gap between the large-scale galaxy and the central massive objects that reside there. Using a high resolution simulation of a galaxy forming out of gas cooling and settling into a disc, we study the formation and properties of nuclear discs. Gas, driven to the centre by a bar, settles into a rotating star-forming nuclear disc (ND). This ND is thinner, younger, kinematically cooler, and more metal-rich than the surrounding bar. The ND is elliptical and orthogonal to the bar. The complex kinematics in the region of the ND are a result of the superposition of older stars streaming along the bar and younger stars circulating within the ND. The signature of the ND is therefore subtle in the kinematics. Instead the ND stands out clearly in metallicity and age maps. We compare the model to the density and kinematics of real galaxies with NDs finding qualitative similarities. Our results suggest that gas dissipation is very important for forming nuclear structures.

show abstract

“…Given the available data, ND formation through dissipationless processes cannot be excluded. Agarwal and Milosavljević (2011) proposed that NDs form out of the debris of infalling star clusters and Portaluri et al (2013) showed that such a scenario is consistent with the available kinematic and photometric data. It has also been demonstrated that NDs can be formed from accreted dwarf satellites settling into rotationally supported NDs (Eliche-Moral et al 2011).…”

Section: Fig 53mentioning

confidence: 53%

Galactic Bulges

2016

Astrophysics and Space Science Library

View full text Add to dashboard Cite

978-3-319-19377-9 ISBN 978-3-319-19378-6 (eBook) DOI 10.1007/978-3-319-19378-6 Library of Congress Control Number: 2015949217 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2016 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made.Cover Illustration: In the cover the 3.6 images of one nearby galaxy, NGC 4565, is shown. The images are from the Spitzer Survey of Stellar Structure in Galaxies (PI Kartik Sheth).Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media (www.springer.com) PrefaceThe main motivation for this book was our impression that when observers talk about bulges in galaxies, they do not necessarily mean the same thing as people making theoretical models. Even among the observers, it is not always clear what they mean by classical and pseudobulges. According to most researchers, classical bulges are highly relaxed systems typically formed in galaxy mergers or by coalescence of massive gas clumps at high redshifts, whereas pseudobulges have more disc-like properties. Some people divide pseudobulges further into discy pseudobulges, defined as small central discs in the plane of the galactic disc, and boxy/peanut bulges which are actually dynamically heated, vertically thick inner parts of bars. Galaxies can also have central star clusters, usually called nuclear clusters, which structures are not called bulges in this book (see the review by Cole and Debattista). In recent years significant progress has been made both on the theoretical and observational sides, including galactic and extragalactic research. In this book we try to bring all these communities closer to each other.Most probably many of us share the Copernican approach trying to understand the universe with some simple beautiful theory. Such an attempt is the current paradigm of structure formation, i.e., the hierarchical growth of dark matter halos ( CDM), and the subsequent formatio...

show abstract

Searching for nuclear stellar discs in simulations of star cluster mergers

Cited by 12 publications

References 49 publications

Diversity of nuclear star cluster formation mechanisms revealed by their star formation histories

Diversity of nuclear star cluster formation mechanisms revealed by their star formation histories

The formation of stellar nuclear discs in bar-induced gas inflows

Galactic Bulges

Contact Info

Product

Resources

About