MOCCA-SURVEY database I. Accreting white dwarf binary systems in globular clusters — IV. cataclysmic variables — properties of bright and faint populations. (arXiv:1811.04937v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Belloni_D/0/1/0/all/0/1">Diogo Belloni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Giersz_M/0/1/0/all/0/1">Mirek Giersz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sandoval_L/0/1/0/all/0/1">Liliana E. Rivera Sandoval</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Askar_A/0/1/0/all/0/1">Abbas Askar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ciecielag_P/0/1/0/all/0/1">Paweł Ciecieląg</a>
We investigate here populations of cataclysmic variables (CVs) in a set of
288 globular cluster (GC) models evolved with the MOCCA code. This is by far
the largest sample of GC models ever analysed with respect to CVs. Contrary to
what has been argued for a long time, we found that dynamical destruction of
primordial CV progenitors is much stronger in GCs than dynamical formation of
CVs, and that dynamically formed CVs and CVs formed under no/weak influence of
dynamics have similar white dwarf mass distributions. In addition, we found
that, on average, the detectable CV population is predominantly composed of CVs
formed via typical common envelope phase (CEP) ($gtrsim70$ per cent), that
only $approx2-4$ per cent of all CVs in a GC is likely to be detectable, and
that core-collapsed models tend to have higher fractions of bright CVs than
non-core-collapsed ones. We also consistently show, for the first time, that
the properties of bright and faint CVs can be understood by means of the pre-CV
and CV formation rates, their properties at their formation times and cluster
half-mass relaxation times. Finally, we show that models following the initial
binary population proposed by Kroupa and set with low CEP efficiency better
reproduce the observed amount of CVs and CV candidates in NGC 6397, NGC 6752
and 47 Tuc. To progress with comparisons, the essential next step is to
properly characterize the candidates as CVs (e.g. by obtaining orbital periods
and mass ratios).
We investigate here populations of cataclysmic variables (CVs) in a set of
288 globular cluster (GC) models evolved with the MOCCA code. This is by far
the largest sample of GC models ever analysed with respect to CVs. Contrary to
what has been argued for a long time, we found that dynamical destruction of
primordial CV progenitors is much stronger in GCs than dynamical formation of
CVs, and that dynamically formed CVs and CVs formed under no/weak influence of
dynamics have similar white dwarf mass distributions. In addition, we found
that, on average, the detectable CV population is predominantly composed of CVs
formed via typical common envelope phase (CEP) ($gtrsim70$ per cent), that
only $approx2-4$ per cent of all CVs in a GC is likely to be detectable, and
that core-collapsed models tend to have higher fractions of bright CVs than
non-core-collapsed ones. We also consistently show, for the first time, that
the properties of bright and faint CVs can be understood by means of the pre-CV
and CV formation rates, their properties at their formation times and cluster
half-mass relaxation times. Finally, we show that models following the initial
binary population proposed by Kroupa and set with low CEP efficiency better
reproduce the observed amount of CVs and CV candidates in NGC 6397, NGC 6752
and 47 Tuc. To progress with comparisons, the essential next step is to
properly characterize the candidates as CVs (e.g. by obtaining orbital periods
and mass ratios).
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