On the rotation of nuclear star clusters formed by cluster inspirals

Tsatsi, Athanasia; Mastrobuono-Battisti, Alessandra; Ven, Glenn van de; Perets, Hagai B.; Bianchini, P.; Neumayer, Nadine

doi:10.1093/mnras/stw2593

Cited by 67 publications

(79 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of the young stellar disc as well as the existence of H ii regions and young stars within the central 100 pc of the Milky Way (Figer et al 2004) suggest that the GC went through recent star formation processes in this region (Genzel et al 2010). However, while the majority of current studies focused on the understanding of the build-up of NSCs through the infall of stellar clusters (Tremaine et al 1975;Capuzzo-Dolcetta 1993;Antonini et al 2012;Arca-Sedda & Capuzzo-Dolcetta 2014;Mastrobuono-Battisti et al 2014;Gnedin et al 2014;Arca-Sedda et al 2015;Antonini et al 2015;Arca-Sedda & Capuzzo-Dolcetta 2017a,b;Tsatsi et al 2017;Abbate et al 2018), very few studies so far explore the long-term effects and evolution of NSCs with insitu star formation (Aharon & Perets 2015;Guillard et al 2016;Baumgardt et al 2018). In particular the potential insitu star formation producing stellar discs such as the one observed in the GC had not been investigated.…”

Section: Introductionmentioning

confidence: 99%

Star formation at the Galactic Centre: coevolution of multiple young stellar discs

Mastrobuono-Battisti

Perets

Gualandris

et al. 2019

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

Studies of the Galactic Centre suggest that in-situ star formation may have given rise to the observed stellar population near the central supermassive black hole (SMBH). Direct evidence for a recent starburst is provided by the currently observed young stellar disc (2-7 Myr) in the central 0.5 pc of the Galaxy. This result suggests that star formation in galactic nuclei may occur close to the SMBH and produce initially flattened stellar discs. Here we explore the possible build-up and evolution of nuclear stellar clusters near SMBHs through in-situ star formation producing stellar discs similar to those observed in the Galactic Centre and other nuclei. We make use of N-body simulations to model the evolution of multiple young stellar discs, and explore the potential observable signatures imprinted by such processes. Each of the five simulated discs is evolved for 100 Myr before the next one is introduced in the system. We find that populations born at different epochs show different morphologies and kinematics. Older and presumably more metal poor populations are more relaxed and extended, while younger populations show a larger amount of rotation and flattening. We conclude that star formation in central discs can reproduce the observed properties of multiple stellar populations in galactic nuclei differing in age, metallicity and kinematic properties.

show abstract

Section: Introductionmentioning

confidence: 99%

Star formation at the Galactic Centre: coevolution of multiple young stellar discs

Mastrobuono-Battisti

Perets

Gualandris

et al. 2019

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

“…Strong rotation is seen in nearby nuclear star clusters (Seth et al 2008b;Seth 2010;Feldmeier et al 2014;Nguyen et al 2017), with V s values ranging between ∼0.3 and 1.3, with both early and late-type galaxies showing strong rotation. This rotation can be created through cluster merging, but the strongest rotation is likely to be due to in situ star formation (e.g., Hartmann et al 2011;Tsatsi et al 2017). Larger scale (∼100 pc) nuclear disks are also common (Launhardt et al 2002;Balcells et al 2007;Chilingarian 2009;Morelli et al 2010;Toloba et al 2014), and stripping of these could also yield rotating UCDs.…”

mentioning

confidence: 99%

Upper Limits on the Presence of Central Massive Black Holes in Two Ultra-compact Dwarf Galaxies in Centaurus A

Voggel

Seth

Neumayer

et al. 2018

ApJ

Self Cite

View full text Add to dashboard Cite

The recent discovery of massive black holes (BHs) in the centers of high-mass ultra-compact dwarf galaxies (UCDs) suggests that at least some are the stripped nuclear star clusters of dwarf galaxies. We present the first study that investigates whether such massive BHs, and therefore stripped nuclei, also exist in low-mass (M<10 7 M e ) UCDs. We constrain the BH masses of two UCDs located in Centaurus A (UCD 320 and UCD 330) using Jeans modeling of the resolved stellar kinematics from adaptive optics data obtained with the SINFONI integral field spectrograph at the Very Large Telescope (VLT/SINFONI). No massive BHs are found in either UCD. We find a 3σ upper limit on the central BH mass in UCD 330 of M • <1.0 × 10 5 M e , which corresponds to 1.7% of the total mass. This excludes a high-mass fraction BH and would only allow low-mass BHs similar to those claimed to be detected in Local Group globular clusters. For UCD 320, poorer data quality results in a less constraining 3σ upper limit of M • <1 × 10 6 M e , which is equal to 37.7% of the total mass. The dynamical massto-light ratios of UCD 320 and UCD 330 are not inflated compared to predictions from stellar population models. The non-detection of BHs in these low-mass UCDs is consistent with the idea that elevated dynamical mass-tolight ratios do indicate the presence of a substantial BH. Although no massive BHs are detected, these systems could still be stripped nuclei. The strong rotation (v/σ of 0.3-0.4) in both UCDs and the two-component light profile in UCD 330 support the idea that these UCDs may be stripped nuclei of low-mass galaxies whose BH occupation fraction is not yet known.

show abstract

“…This finding was confirmed by Fritz et al (2016). In addition, the line-of-sight velocity map shows a perpendicular rotating substructure, which may be the result of star cluster infall (Feldmeier et al 2014;Tsatsi et al 2017). In summary, the Milky Way appears to contain a rather typical example for an NSC, because many of its properties are entirely consistent with the general sample of NSCs in external galaxies (see also Table 2).…”

Section: Properties Of the Milky Way Nuclear Star Clustermentioning

confidence: 65%

“…In a similar vein, successfully reproduced the density profile of the Milky Way NSC from the accretion of globular clusters, but also concluded that the observed luminosity function requires younger stars and therefore suggested that only about half the NSC mass can originate from globular cluster inspirals. The rotation of NSCs was investigated by Tsatsi et al (2017), who found that their models could match the observed flattening (Schödel et al 2014a), and rotation signature (Feldmeier et al 2014) of the Milky Way NSC (Figs. 10 and 11).…”

Section: Globular Cluster Infall and Mergingmentioning

confidence: 99%

Nuclear Star Clusters

Neumayer

2015

Proc. IAU

Self Cite

View full text Add to dashboard Cite

We review the current knowledge about nuclear star clusters (NSCs), the spectacularly dense and massive assemblies of stars found at the centers of most galaxies. Recent observational and theoretical work suggest that many NSC properties, including their masses, densities, and stellar populations vary with the properties of their host galaxies. Understanding the formation, growth, and ultimate fate of NSCs therefore is crucial for a complete picture of galaxy evolution. Throughout the review, we attempt to combine and distill the available evidence into a coherent picture of NSC evolution. Combined, this evidence points to a clear transition mass in galaxies of ∼ 10 9 M where the characteristics of nuclear star clusters change. We argue that at lower masses, NSCs are formed primarily from globular clusters that inspiral into the center of the galaxy, while at higher masses, star formation within the nucleus forms the bulk of the NSC. We also discuss the coexistence of NSCs and central black holes, and how their growth may be linked. The extreme densities of NSCs and their interaction with massive black holes lead to a wide range of unique phenomena including tidal disruption and gravitational wave events. Lastly, we review the evidence that many NSCs end up in the halos of massive galaxies stripped of the stars that surrounded them, thus providing valuable tracers of the galaxies' accretion histories.

show abstract

On the rotation of nuclear star clusters formed by cluster inspirals

Cited by 67 publications

References 47 publications

Star formation at the Galactic Centre: coevolution of multiple young stellar discs

Star formation at the Galactic Centre: coevolution of multiple young stellar discs

Upper Limits on the Presence of Central Massive Black Holes in Two Ultra-compact Dwarf Galaxies in Centaurus A

Nuclear Star Clusters

Contact Info

Product

Resources

About