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Islam in Satire : Representations, Taste Cultures, and Liquid Racism
MOCCA-SURVEY Database I: Assessing GW kick retention fractions for BH-BH mergers in globular clusters
Anisotropy of gravitational wave (GW) emission results in a net momentum gained by the black hole (BH) merger product, leading to a recoil velocity up to ∼103 km s−1, which may kick it out of a globular cluster (GC). We estimate GW kick retention fractions of merger products assuming different models for BH spin magnitude and orientation. We check how they depend on BH–BH merger time and propertie
MOCCA-Survey Database I. Unravelling black hole subsystems in globular clusters
In this paper, we discuss how the structural and observational properties of globular clusters (GCs) can be used to infer the presence of a black hole system (BHS) inhabiting their inner regions. We propose a novel way to define the BHS size as the radius from the GC centre within which half of the mass is in stellar mass BHs and the remaining half is in other stars. Using this definition, similar
The origin of the first neutron star textendash neutron star merger
The first neutron star-neutron star (NS-NS) merger was discovered on August 17, 2017 through gravitational waves (GW170817) and followed with electromagnetic observations. This merger was detected in an old elliptical galaxy with no recent star formation. We perform a suite of numerical calculations to understand the formation mechanism of this merger. We probe three leading formation mechanisms o
MOCCA-Survey Database I: Galactic globular clusters harbouring a black hole subsystem
There have been increasing theoretical speculations and observational indications that certain globular clusters (GCs) could contain a sizeable population of stellar mass black holes (BHs). In this paper, we shortlist at least 29 Galactic GCs that could be hosting a subsystem of BHs (BHS). In a companion paper, we analysed results from a wide array of GC models (simulated with the MOCCA code for c
MOCCA-SURVEY Database. I. Eccentric Black Hole Mergers during Binary-Single Interactions in Globular Clusters
We estimate the population of eccentric gravitational wave (GW) binary black hole (BBH) mergers forming during binary–single interactions in globular clusters (GCs), using ~800 GC models that were evolved using the MOCCA code for star cluster simulations as part of the MOCCA-Survey Database I project. By re-simulating BH binary–single interactions extracted from this set of GC models using an N-bo
COCOA Code for Creating Mock Observations of Star Cluster Models
We introduce and present results from the cocoa (Cluster simulatiOn Comparison with ObservAtions) code that has been developed to create idealized mock photometric observations using results from numerical simulations of star cluster evolution. cocoa is able to present the output of realistic numerical simulations of star clusters carried out using Monte Carlo or N-body codes in a way that is usef
On the initial binary population for star cluster simulations
Colour–magnitude diagrams (CMDs) are powerful tools that might be used to infer stellar properties in globular clusters (GCs), for example, the binary fraction and their mass ratio (q) distribution. In the past few years, observations have revealed that q distributions of GC main-sequence binaries are generally flat, and a distribution characterized by a strong increase towards q ≈ 1 is not typica
The dynamical origin of multiple populations in intermediate-age clusters in the Magellanic Clouds
MOCCA-SURVEY database I. Accreting white dwarf binary systems in globular clusters - III. Cataclysmic variables - implications of model assumptions
In this third of a series of papers related to cataclysmic variables (CVs) and related objects, we analyse the population of CVs in a set of 12 globular cluster models evolved with the MOCCA Monte Carlo code, for two initial binary populations (IBPs), two choices of common-envelope phase (CEP) parameters, and three different models for the evolution of CVs and the treatment of angular momentum los
Prospects for detection of intermediate-mass black holes in globular clusters using integrated-light spectroscopy
The detection of intermediate-mass black holes (IMBHs) in Galactic globular clusters (GCs) has so far been controversial. In order to characterize the effectiveness of integrated-light spectroscopy through integral field units, we analyse realistic mock data generated from state-of-the-art Monte Carlo simulations of GCs with a central IMBH, considering different setups and conditions varying IMBH
MOCCA-SURVEY Database I: Is NGC 6535 a dark star cluster harbouring an IMBH?
We describe the dynamical evolution of a unique type of dark star cluster model in which the majority of the cluster mass at Hubble time is dominated by an intermediate-mass black hole (IMBH). We analysed results from about 2000 star cluster models (Survey Database I) simulated using the Monte Carlo code MOnte Carlo Cluster simulAtor and identified these dark star cluster models. Taking one of the
MOCCA-SURVEY database I. Accreting white dwarf binary systems in globular clusters II. Cataclysmic variables - progenitors and population at birth
MOCCA-SURVEY Database - I. Coalescing binary black holes originating from globular clusters
MOCCA-SURVEY database I. Accreting white dwarf binary systems in globular clusters I. Cataclysmic variables textendash present-day population
The dragon simulations: globular cluster evolution with a million stars
Introducing the dragon simulation project, we present direct N-body simulations of four massive globular clusters (GCs) with 106 stars and 5 per cent primordial binaries at a high level of accuracy and realism. The GC evolution is computed with nbody6++gpu and follows the dynamical and stellar evolution of individual stars and binaries, kicks of neutron stars and black holes (BHs), and the effect
MOCCA code for star cluster simulation: comparison with optical observations using COCOA
Cataclysmic variables in globular clusters . First results on the analysis of the MOCCA simulations database
In this first investigation of the MOCCA database with respect to cataclysmic variables, we found that for models with Kroupa initial distributions, considering the standard value of the efficiency of the common-envelope phase adopted in BSE, no single cataclysmic variable was formed only via binary stellar evolution, i. e., in order to form them, strong dynamical interactions have to take place.
Formation mechanisms of IMBH in globular clusters
We very briefly discuss proposed in the literature possible scenarios for intermediate mass black holes formation in globular clusters. We also discuss the results of the MOCCA simulations of about 2000 models (BigSurvey) regarding the distribution of events connected with electromagnetic and gravitational radiations, namely: mass transfer on IMBH, collisions and mergers with IMBH and mergers with