Inverse dynamical population synthesis: Constraining the initial conditions of young stellar clusters by studying their binary populations

By M. Marks, Pavel Kroupa. 2012

154 citations recorded by the source corpus.

Binary populations in young star clusters show multiplicit y fractions both lower and up to twice as high as those observed in the Galactic field. We follow the evolution of a population of bin ary stars in dense and loose star clusters starting with an in variant initial binary population and a formal multiplicity fracti on of unity, and demonstrate that these models can explain the observed binary properties in Taurus, ρ Ophiuchus, Chamaeleon, Orion, IC 348, Upper Scorpius A, Praesepe, and the Pleiades. The model needs to consider solely different birth densities for these regions. The evolved theore tical orbital-parameter distributions are highly probable parent distributions for the observed ones. We con strain the birth conditions (stellar mass, Mecl, and half-mass radius, rh) for the derived progenitors of the star clusters and the over all present-day binary fractions allowed by the present model. The results compare very well with properties of molecular cloud clumps on the verge of star formation. Combining these with previously and independently obtained constraints on the birth densities of globular clusters, we identify a weak stellar mass ‐ half- mass radius correlation for cluster-forming cloud clumps, rh/pc∝ (Mecl/M⊙) 0.13±0.04 . The ability of the model to reproduce the binary properties in all the investigated young objects, covering present-da y densities from 1− 10 stars pc −3 (Taurus) to 2× 10 4 stars pc −3 (Orion), suggests that environment-dependent dynamical evolution plays an important role in shaping the present-day properti es of binary populations in star clusters, and that the initial binary pr operties may not vary dramatically between different environments.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/375af851cc3b09926a7e186fe418b18a10eaaa69

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Citations in the corpus

The big problems in star formation: The star formation rate, stellar clustering, and the initial mass function (2014, background): “There have been some theoretical attempts to reverse-engineer the binary populations of embedded clusters based on dynamical modeling (Marks & Kroupa 2011, 2012), but these are still works in progress, and have not yet been used in an attempt to make binarity corrections to IMF measurements in…”
Kinematics in Young Star Clusters and Associations with Gaia DR2 (2018, background): “Furthermore, Marks & Kroupa (2012) argue that the low binary fractions observed in young star clusters imply these clusters were more compact upon formation.”
Physical Processes in the Interstellar Medium (2014, background): “The IMF has three properties that appear to be relatively robust in diverse environments (see Figure 20).”
STELLAR POPULATIONS IN THE CENTRAL 0.5 pc OF THE GALAXY. II. THE INITIAL MASS FUNCTION (2013, background): “Lastly, some observations suggest multiplicity properties may evolve over time differently for clusters with different masses or stellar densities (e. g. Kroupa 1995; Duchêne et al. 1999; Köhler et al. 2006; Marks & Kroupa 2012).”
Galaxies as simple dynamical systems: observational data disfavor dark matter and stochastic star formation (2014, background): “ters to form in molecular cloud cores along thin ﬁlaments with radii or cross sections near 0.1 pc [278], which is consistent with the independently obtained radius–mass relation of embedded clusters [279]. The masses of embedded clusters range from groups of a dozen binaries (ˇ10M , which appear to”
The stellar and sub-stellar IMF of simple and composite populations (2011, background): “The above work suggests that even clusters as young as the Pleiades are significantly evolved because clusters of all masses form from highly concentrated embedded morphologies (Kroupa 2005; Marks & Kroupa 2010, 2012; Conroy 2012).”
Stellar Multiplicity (2013, background): “Although it has long been proposed that multiplicity is a smooth function of the stellar density, the statistical precision of current surveys in intermediate regions, such as the Ophiuchus cloud, do not conclusively support his scenario (King et al. 2012a, Marks & Kroupa 2012).”
Evolutionary roads leading to low effective spins, high black hole masses, and O1/O2 rates for LIGO/Virgo binary black holes (2017, background): “Notably, both theoretical arguments (see Klencki et al. 2018, for an overview) and observations of some GCs in the Milky Way (Marks & Kroupa 2012; Marks et al. 2012) seem to point towards a top-heavy IMF12 in lowmetallicity galaxies, which are likely an important formation site of massive BH-BH…”
THE VLA NASCENT DISK AND MULTIPLICITY SURVEY OF PERSEUS PROTOSTARS (VANDAM). II. MULTIPLICITY OF PROTOSTARS IN THE PERSEUS MOLECULAR CLOUD (2016, background): “However, the mainsequence field multiple systems have been shaped by dynamical evolution (Marks & Kroupa 2012, e.g., three-body interactions, interactions with cluster members).”