Do star clusters form in a completely mass-segregated way?

  title={Do star clusters form in a completely mass-segregated way?},
  author={V'aclav Pavl'ik and Pavel Kroupa and Ladislav {\vS}ubr},
  journal={Astronomy \& Astrophysics},
Context. ALMA observations of the Serpens South star-forming region suggest that stellar protoclusters may be completely mass segregated at birth. Independent observations also suggest that embedded clusters form segregated by mass. Aims. As the primordial mass segregation seems to be lost over time, we aim to study on which timescale an initially perfectly mass-segregated star cluster becomes indistinguishable from an initially not mass-segregated cluster. As an example, the Orion Nebula… 

Primordial mass segregation of star clusters with primordial binaries

Context. Observations of young star-forming regions suggest that star clusters are born completely mass segregated. These initial conditions are, however, gradually lost as the star cluster evolves

Primordial mass segregation of star clusters: The role of binary stars

  • V'aclav Pavl'ik
  • Physics
    Contributions of the Astronomical Observatory Skalnaté Pleso
  • 2020
Observational results of young star-forming regions suggest that star clusters are completely mass segregated at birth. As a star cluster evolves dynamically, these initial conditions are gradually

Do ultracompact dwarf galaxies form monolithically or as merged star cluster complexes?

Some ultra-compact dwarf galaxies (UCDs) have elevated observed dynamical V-band massto-light (M/LV) ratios with respect to what is expected from their stellar populations assuming a canonical

The Lifetimes of Star Clusters Born with a Top-heavy IMF

Several observational and theoretical indications suggest that the initial mass function (IMF) becomes increasingly top-heavy (i.e., overabundant in high-mass stars with mass ) with decreasing

Unifying low- and high-mass star formation through density-amplified hubs of filaments

Context. Star formation takes place in giant molecular clouds, resulting in mass-segregated young stellar clusters composed of Sun-like stars, brown dwarfs, and massive O-type(50–100 M⊙) stars. Aims.

The possible role of stellar mergers for the formation of multiple stellar populations in globular clusters

Many possible scenarios for the formation of multiple stellar populations (MSPs) in globular clusters (GCs) have been discussed so far, including the involvement of asymptotic giant branch stars,

Physics and evolution of the most massive stars in 30 Doradus

The identification of stellar-mass black-hole mergers with up to 80 Msun as powerful sources of gravitational wave radiation led to increased interest in the physics of the most massive stars. The

Uncovering a 260 pc wide, 35-Myr-old filamentary relic of star formation

Several recent studies have shown that the Vela OB2 region hosts a complex constellation of sub-populations with ages in the range 10 to 50 Myr. Such populations might represent the best example of

Assessing membership projection errors in star forming regions

Context. Young stellar clusters harbour complex spatial structures emerging from the star formation process. Identifying stellar over-densities is a key step in better constraining how these

How fast do young star clusters expel their natal gas? Estimating the upper limit of the gas expulsion time-scale

Formation of massive stars within embedded star clusters starts a complex interplay between their feedback, inflowing gas and stellar dynamics, which often includes close stellar encounters.



Evidence for Primordial Mass Segregation in Globular Clusters

We have studied the dissolution of initially mass-segregated and unsegregated star clusters due to two-body relaxation in external tidal fields, using Aarseth’s collisional N-body code NBODY4 on

The effect of primordial mass segregation on the size scale of globular clusters

We use direct $N$-body calculations to investigate the impact of primordial mass segregation on the size scale and mass-loss rate of star clusters in a galactic tidal field. We run a set of

Distribution of Serpens South protostars revealed with ALMA

Context. Clusters are common sites of star formation, whose members display varying degrees of mass segregation. The cause may be primordial or dynamical, or a combination both. If mass segregation

Star Formation in Space and Time: The Orion Nebula Cluster

We examine the pattern of star birth in the Orion Nebula cluster (ONC), with the goal of discerning the cluster's formation mechanism. Outside the Trapezium, the distribution of stellar masses is

Evidence for feedback and stellar-dynamically regulated bursty star cluster formation: the case of the Orion Nebula Cluster

(abridged) A scenario for the formation of multiple co-eval populations separated in age by about 1 Myr in very young clusters (VYCs, ages less than 10 Myr) and with masses in the range 600-20000

A Preliminary Study of the Orion Nebula Cluster Structure and Dynamics

We use optical and near-infrared star counts to explore the structure and dynamics of the Orion Nebula Cluster (ONC). This very young (<1 Myr) cluster is not circularly symmetric in projection but is

Possible smoking-gun evidence for initial mass segregation in re-virialized post-gas expulsion globular clusters

We perform a series of direct N-body calculations to investigate the effect of residual gas expulsion from the gas-embedded progenitors of present-day globular clusters (GCs) on the stellar mass


The Orion A molecular cloud is one of the most well-studied nearby star-forming regions, and includes regions of both highly clustered and more dispersed star formation across its full extent. Here,


Observations suggest that there is a significant fraction of O stars in the field of the Milky Way that appear to have formed in isolation or in low-mass clusters (<100 ). The existence of these

The formation of a bound star cluster: from the orion nebula cluster to the pleiades

Summary Direct N-body calculations are presented of the formation of Galactic clusters using GasEx, which is a variant of the code Nbody6. The calculations focus on the possible evolution of the