A discontinuity in the low-mass IMF - the case of high multiplicity
arXiv:0808.2644 · doi:10.1111/j.1365-2966.2008.13827.x
Abstract
The empirical binary properties of brown dwarfs (BDs) differ from those of normal stars suggesting BDs form a separate population. Recent work by Thies & Kroupa revealed a discontinuity of the initial mass function (IMF) in the very-low-mass star regime under the assumption of a low multiplicity of BDs of about 15 per cent. However, previous observations had suggested that the multiplicity of BDs may be significantly higher, up to 45 per cent. This contribution investigates the implication of a high BD multiplicity on the appearance of the IMF for the Orion Nebula Cluster, Taurus-Auriga, IC 348 and the Pleiades. We show that the discontinuity remains pronounced even if the observed MF appears to be continuous, even for a BD binary fraction as high as 60%. We find no evidence for a variation of the BD IMF with star-forming conditions. The BD IMF has a power-law index alpha = +0.3 and about two BDs form per 10 low-mass stars assuming equal-mass pairing of BDs.
7 pages, 5 figures. Updated to match published version
References in corpus (6)
- Brown dwarf formation by gravitational fragmentation of massive, extended protostellar discs
- Visual Binaries in the Orion Nebula Cluster
- A Survey for Spectroscopic Binaries Among Very Low-Mass Stars
- The Spatial Distribution of Brown Dwarfs in Taurus
- A Multiplicity Census of Young Stars in Chamaeleon I
- Brown dwarf formation by binary disruption
Cited by in corpus (16)
- A Statistical Analysis of SEEDS and Other High-Contrast Exoplanet Surveys: Massive Planets or Low-Mass Brown Dwarfs?
- Exploring the consequences of pairing algorithms for binary stars
- Tidally induced brown dwarf and planet formation in circumstellar discs
- The influence of multiple stars on the high-mass stellar initial mass function and age-dating of young massive star clusters
- Characterizing the Brown Dwarf Formation Channels from the Initial Mass Function and Binary-star Dynamics
- Spectroscopy of Hyades L dwarf candidates
- Sampling methods for stellar masses and the mmax-Mecl relation in the starburst dwarf galaxy NGC 4214
- Formation of freely floating sub-stellar objects via close encounters
- Revisiting the universality of (multiple) star formation in present-day star formation regions
- The dynamical evolution of low-mass hydrogen-burning stars, brown dwarfs and planetary-mass objects formed through disc fragmentation
- Physical parameters of late M-type members of Chamaleon I and TW Hydrae Association: Dust settling, age dispersion and activity
- On the origin of planetary-mass objects in NGC1333
- Using binary statistics in Taurus-Auriga to distinguish between brown dwarf formation processes
- Effects of physical conditions on the stellar initial mass function: The low-metallicity star-forming region Sh 2-209
- Spatial differences between stars and brown dwarfs: a dynamical origin?
- OGLE-2017-BLG-1038: A Possible Brown-dwarf Binary Revealed by Spitzer Microlensing Parallax