Related papers: Reverse dynamical evolution of Eta Chamaeleontis
Eta Chamaeleontis is a unique young (~9 Myr) association with 18 systems concentrated in a radius of ~35 arcmin, i.e. 1pc at the cluster distance of 97pc. No other members have been found up to 1.5 degrees from the cluster centre. The…
We report new results in our continuing study of the unique compact (1 pc extent), nearby (d = 97 pc), young (t = 9 Myr) stellar cluster dominated by the B9 star eta Chamaeleontis. An optical photometric survey spanning 1.3 x 1.3 pc adds…
We study the dynamical evolution of the young star cluster Arches and its dependence on the assumed initial stellar mass function (IMF). We perform many direct $N$-body simulations with various initial conditions and two different choices…
We undertake a systematic analysis of the early (< 0.5 Myr) evolution of clustering and the stellar initial mass function in turbulent fragmentation simulations. These large scale simulations for the first time offer the opportunity for a…
We report the outcome of the deep optical/infrared photometric survey of the central region (33 X 33 arcmin or 0.9 pc^2) of the eta Chamaeleontis pre-main sequence star cluster. The completeness limits of the photometry are I = 19.1, J =…
We present IRS spectra and revised MIPS photometry for the 18 members of the Eta Chamaeleontis cluster. Aged 8 Myr, the Eta Cha cluster is one of the few nearby regions within the 5-10 Myr age range, during which the disk fraction decreases…
The universality or non-universality of the initial mass function (IMF) has significant implications for determining star formation rates and star formation histories from photometric properties of stellar populations. We reexamine whether…
Few topics in astronomy initiate such vigorous discussion as whether or not the initial mass function (IMF) of stars is universal, or instead sensitive to the initial conditions of star formation. The distinction is of critical importance:…
I present a new census of the stellar population in the Chamaeleon I star-forming region. Using optical and near-IR photometry and followup spectroscopy, I have discovered 50 new members of Chamaeleon I, expanding the census of known…
The stellar initial mass function (IMF) seems to be variable and not universal, as argued in the literature in the last three decades. Several relations among the low-mass end of the IMF slope and other stellar population, photometric or…
When star clusters are formed at low star-formation rates (SFRs), their stellar initial mass function (IMF) can hardly be filled continuously with stars at each mass. This lack holds for massive stars and is observationally verified by the…
The initial-final mass relation (IFMR) represents the total mass lost by a star during the entirety of its evolution from the zero age main sequence to the white dwarf cooling track. The semi-empirical IFMR is largely based on observations…
The mass of unresolved young star clusters derived from spectro-photometric data may well be off by a factor of 2 or more once the migration of massive stars driven by mass segregation is accounted for. We quantify this effect for a large…
We present a combined analysis of the low-mass Initial Mass Function (IMF) for seven star forming regions. We first demonstrate that the ratios of stars to brown dwarfs are consistent with a single underlying IMF. Assuming the underlying…
Young, massive stellar clusters offer a prime setting to explore brown dwarf (BD) formation under high densities and intense UV radiation. Trumpler 14 (Tr 14), a 1 Myr-old cluster located at a distance of 2.4 kpc, and particularly rich in…
In the star formation process, the vital impact of environmental factors such as feedback from massive stars and stellar density on the form of the initial mass function (IMF) at low-mass end is yet to be understood. Hence a systematic,…
The stellar initial mass function (IMF) is among the most fundamental distributions in astrophysics, defined as the mass spectrum of stars produced in a single star-formation event. Even in the solar neighbourhood, where measurements can be…
We review recent advances in our understanding of the origin of the initial mass function (IMF). We emphasize the use of numerical simulations to investigate how each physical process involved in star formation affects the resulting IMF. We…
The initial mass function (IMF), binary fraction and distributions of binary parameters (mass ratios, separations and eccentricities) are indispensable input for simulations of stellar populations. It is often claimed that these are poorly…
Binary populations in young star clusters show multiplicity fractions both lower and up to twice as high as those observed in the Galactic field. We follow the evolution of a population of binary stars in dense and loose star clusters…