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Related papers: The stellar IMF at very low metallicities

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The initial mass function (IMF) succinctly characterizes a stellar population, provides a statistical measure of the end result of the star-formation process, and informs our under- standing of the structure and dynamical evolution of…

Solar and Stellar Astrophysics · Physics 2011-07-25 Kevin R. Covey , Nate Bastian , Michael R. Meyer

The stellar initial mass function (IMF) is commonly interpreted to be a scale-invariant probability density distribution function (PDF) such that many small clusters yield the same IMF as one massive cluster of the same combined number of…

Astrophysics of Galaxies · Physics 2023-02-22 Zhiqiang Yan , Tereza Jerabkova , Pavel Kroupa

Observations of both galaxies in the distant Universe and local starbursts are showing increasing evidence for very hard ionizing spectra that stellar population synthesis models struggle to reproduce. Here we explore the effects of the…

Astrophysics of Galaxies · Physics 2019-01-23 E. R. Stanway , J. J. Eldridge

We present a simple statistical analysis of recent numerical simulations exploring the correlation between the core mass function obtained from the fragmentation of a molecular cloud and the stellar mass function which forms from these…

Solar and Stellar Astrophysics · Physics 2015-05-20 Gilles Chabrier , Patrick Hennebelle

The observed distribution of IMF shapes can be understood as statistical sampling from a universal IMF and variations that result from stellar-dynamical processes. However, young star clusters appear to have an IMF biased towards low-mass…

Astrophysics · Physics 2007-05-23 Pavel Kroupa

(abridged) The stellar initial mass function (IMF) can be conveniently represented as a canonical two-part power law function and is largely invariant for star formation regions evident in the Local Group of galaxies. The IMF is a…

Astrophysics of Galaxies · Physics 2018-12-27 Pavel Kroupa , Tereza Jerabkova

We present an analytical determination of the star formation rate (SFR) in molecular clouds, based on a time-dependent extension of our analytical theory of the stellar initial mass function (IMF). The theory yields SFR's in good agreement…

Astrophysics of Galaxies · Physics 2015-05-30 Patrick Hennebelle , Gilles Chabrier

Dust enables low-mass stars to form from low-metallicity gas by inducing fragmentation of clouds via the cooling by its thermal emission. Dust may, however, be evacuated from star-forming clouds due to radiation force from massive stars. We…

Astrophysics of Galaxies · Physics 2018-05-02 Hajime Fukushima , Hidenobu Yajima , Kazuyuki Omukai

The influence of the first stars on the formation of second-generation objects at high redshift may be determined, in part, by their metal enrichment of surrounding gas. At a critical metallicity, Zcrit, primordial gas cools more…

Astrophysics · Physics 2009-11-13 Fernando Santoro , J. Michael Shull

The stellar initial mass function (IMF) of early-type galaxies is the combination of the IMF of the stellar population formed in-situ and that of accreted stellar populations. Using as an observable the effective IMF $\alpha_{IMF}$, defined…

Astrophysics of Galaxies · Physics 2017-01-18 Alessandro Sonnenfeld , Carlo Nipoti , Tommaso Treu

The observed rest-UV luminosity function at cosmic dawn ($z \sim 8-14$) measured by JWST revealed an excess of UV-luminous galaxies relative to many pre-launch theoretical predictions. A high star-formation efficiency (SFE) and a top-heavy…

The stellar initial mass function (IMF) describes the distribution of stellar masses that form in a given star formation event. The long main-sequence lifetimes of low-mass stars mean that the IMF in this regime (below $\sim 1…

Recent estimates point to abundances of z > 4 sub-millimeter (sub-mm) galaxies far above model predictions. The matter is still debated. According to some analyses the excess may be substantially lower than initially thought and perhaps…

Astrophysics of Galaxies · Physics 2020-03-06 Zhen-Yi Cai , Gianfranco De Zotti , Matteo Bonato

We investigate the formation of extremely metal-poor (EMP) stars that are observed in the Galactic halo and neighboring ultra-faint dwarf galaxies. Their low metal abundances (${\rm [Fe/H]} < -3$) indicate that their parent clouds were…

Astrophysics of Galaxies · Physics 2018-11-14 Gen Chiaki , John H. Wise

Abridged: We have undertaken a series of hydrodynamical simulations of multiple star formation in small turbulent molecular clouds. Our goal is to determine the sensitivity of the properties of the resulting stars and brown dwarfs to…

Astrophysics · Physics 2009-11-10 E. J Delgado-Donate , C. J. Clarke , M. R. Bate

The stellar initial mass function (IMF) is commonly assumed to be an invariant probability density distribution function of initial stellar masses being represented by the canonical IMF. As a consequence the galaxy-wide IMF (gwIMF), defined…

Astrophysics of Galaxies · Physics 2018-11-28 T. Jerabkova , A. H. Zonoozi , P. Kroupa , G. Beccari , Z. Yan , A. Vazdekis , Z. -Y. Zhang

Here we model a star forming factory in which the continuous creation of stars results in a highly concentrated, massive (globular cluster-like) stellar system. We show that under very general conditions a large-scale gravitational…

Extremely metal poor stars have been the focus of much recent attention owing to the expectation that their chemical abundances can shed light on the metal and dust yields of the earliest supernovae. We present our most realistic simulation…

Astrophysics of Galaxies · Physics 2016-09-21 Jeremy S. Ritter , Chalence Safranek-Shrader , Milos Milosavljevic , Volker Bromm

It is believed that the majority of stars form in clusters. Therefore it is likely that the gas physical conditions that prevail in forming clusters, largely determine the properties of stars that form and in particular the initial mass…

Astrophysics of Galaxies · Physics 2015-06-05 Patrick Hennebelle

We present a detailed parameter study of collapsing turbulent cloud cores, varying the initial density profile and the initial turbulent velocity field. We systematically investigate the influence of different initial conditions on the star…

Solar and Stellar Astrophysics · Physics 2015-05-19 Philipp Girichidis , Christoph Federrath , Robi Banerjee , Ralf S. Klessen