The Lost Dwarfs of Centaurus a and the Formation of Its Dark Globular Clusters

Bovill, Mia Sauda; Puzia, Thomas H.; Ricotti, Massimo; Taylor, Matthew A.

doi:10.3847/0004-637x/832/1/88

Cited by 10 publications

(10 citation statements)

References 113 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3. This result, therefore, suggests the presence of a significant population of BHs in present-day GCs as often envisaged in the literature (e.g., in Strader et al 2012;Taylor et al 2015;Bovill et al 2016;Sollima et al 2016;Peuten et al 2016), which are typically of subsolar metallicity, irrespective of the strength of the external field under which they orbit.…”

Section: The Impact Of Stellar-mass Black Holes On Star Cluster Evolusupporting

confidence: 73%

Stellar-mass black holes in young massive and open stellar clusters and their role in gravitational-wave generation

Banerjee

2017

Mon. Not. R. Astron. Soc.

148

View full text Add to dashboard Cite

Stellar-remnant black holes (BH) in dense stellar clusters have always drawn attention due to their potential in a number of phenomena, especially the dynamical formation of binary black holes (BBH), which potentially coalesce via gravitational-wave (GW) radiation. This study presents a preliminary set of evolutionary models of compact stellar clusters with initial masses ranging over 1.0 × 10 4 M − 5.0 × 10 4 M , and halfmass radius of 2 or 1 pc, that is typical for young massive and starburst clusters. They have metallicities between 0.05Z − Z . Including contemporary schemes for stellar wind and remnant formation, such model clusters are evolved, for the first time, using the state-of-the-art direct N-body evolution program NBODY7 , until their dissolution or at least for 10 Gyr. That way, a self-regulatory behaviour in the effects of dynamical interactions among the BHs is demonstrated. In contrast to earlier studies, the BBH coalescences obtained in these models show a prominence in triple-mediated coalescences while being bound to the clusters, compared to those occurring among the BBHs that are dynamically ejected from the clusters. A broader mass spectrum of the BHs and lower escape velocities of the clusters explored here might cause this difference, which is yet to be fully understood. Among the BBH coalescences obtained here, there are ones that resemble the detected GW151226, LVT151012, and GW150914 events and also ones which are even more massive. A preliminary estimate suggests few 10s-100s of BBH coalescences per year, originating due to dynamics in stellar clusters, that can be detected by the LIGO at its design sensitivity.

show abstract

Section: The Impact Of Stellar-mass Black Holes On Star Cluster Evolusupporting

confidence: 73%

Stellar-mass black holes in young massive and open stellar clusters and their role in gravitational-wave generation

Banerjee

2017

Mon. Not. R. Astron. Soc.

148

View full text Add to dashboard Cite

show abstract

“…Similar suggestions have been made to explain the elevated mass to luminousity ratio in UCDs (Chilingarian et al 2011). Dark stellar clusters around Centaurus A are also believed to be remnants of a stripped dwarf (Bovill et al 2016).…”

Section: Introductionsupporting

confidence: 72%

Formation of massive globular clusters with dark matter and its implication on dark matter annihilation

Wirth,

Bekki,

Hayashi

2020

Preprint

View full text Add to dashboard Cite

Recent observational studies of γ-ray emission from massive globular clusters (GCs) have revealed possible evidence of dark matter (DM) annihilation within GCs. It is, however, still controversial whether the emission comes from DM or from milli-second pulsars. We here present the new results of numerical simulations, which demonstrate that GCs with DM can originate from nucleated dwarfs orbiting the ancient Milky Way (MW). The simulated stripped nuclei (i.e., GCs) have the central DM densities ranging from 0.1 to several M pc −3 , depending on the orbits and the masses of the host dwarf galaxies. However, GCs born outside the central regions of their hosts can have no/little DM after their hosts are destroyed and the GCs become the Galactic halo GCs. These results suggest that only GCs originating from stellar nuclei of dwarfs can possibly have DM. We further calculate the expected γ-ray emission from these simulated GCs and compare them to observations of ω Cen. Given the large range of DM densities in the simulated GCs, we suggest that the recent possible detection of DM annihilation from GCs should be more carefully interpreted.

show abstract

“…Given the rather small probability of formation of BH X-ray binaries, the presence of such candidates may indicate the existence of a much larger population of stellar-mass BHs in GCs (see Strader et al 2012 and references therein). In fact, the recently-discovered very high mass-to-light-ratio GCs or "dark star clusters" (DSC; Banerjee & Kroupa 2011;Taylor et al 2015;Bovill et al 2016;Sollima et al 2016) provide additional indications of the possible presence of large populations of dark remnants in GCs.…”

Section: Introductionmentioning

confidence: 99%

Stellar-mass black holes in young massive and open stellar clusters and their role in gravitational-wave generation – II

Banerjee

2017

Monthly Notices of the Royal Astronomical Society

164

108

View full text Add to dashboard Cite

The study of stellar-remnant black holes (BH) in dense stellar clusters is now in the spotlight, especially due to their intrinsic ability to form binary black holes (BBH) through dynamical encounters, that potentially coalesce via gravitational-wave (GW) radiation. In this work, which is a continuation from a recent study (Paper I), additional models of compact stellar clusters with initial masses 10 5 M and also those with small fractions of primordial binaries ( 10%) are evolved for long term, applying the direct N-body approach, assuming state-of-the-art stellar-wind and remnantformation prescriptions. That way, a substantially broader range of computed models than that in Paper I is achieved. As in Paper I, the general-relativistic BBH mergers continue to be mostly mediated by triples that are bound to the clusters rather than happen among the ejected BBHs. In fact, the number of such in situ BBH mergers, per cluster, tend to increase significantly with the introduction of a small population of primordial binaries. Despite the presence of massive primordial binaries, the merging BBHs, especially the in situ ones, are found to be exclusively dynamically assembled and hence would be spin-orbit misaligned. The BBHs typically traverse through both the LISA's and the LIGO's detection bands, being audible to both instruments. The "dynamical heating" of the BHs keeps the Electron-Capture-Supernova (ECS) neutron stars (NS) from effectively mass segregating and participating in exchange interactions; the dynamically-active BHs would also exchange into any NS binary within 1 Gyr. Such young massive and open clusters have the potential to contribute to the dynamical BBH merger detection rate to a similar extent as their more massive globular-cluster counterparts.

show abstract

The Lost Dwarfs of Centaurus a and the Formation of Its Dark Globular Clusters

Cited by 10 publications

References 113 publications

Stellar-mass black holes in young massive and open stellar clusters and their role in gravitational-wave generation

Stellar-mass black holes in young massive and open stellar clusters and their role in gravitational-wave generation

Formation of massive globular clusters with dark matter and its implication on dark matter annihilation

Stellar-mass black holes in young massive and open stellar clusters and their role in gravitational-wave generation – II

Contact Info

Product

Resources

About