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Related papers: On the Origin of the Salpeter Slope for the Initia…

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We investigate the time evolution and spatial variation of the stellar initial mass function (IMF) in star-forming disk galaxies by using chemodynamical simulations with an IMF model depending both on local densities and metallicities…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Kenji Bekki , Gerhardt R. Meurer

We measure the high-mass stellar initial mass function (IMF) from resolved stars in M33 young stellar clusters. Leveraging \textit{Hubble Space Telescope's} high resolving power, we fully model the IMF probabilistically. We first model the…

The stellar initial mass function (IMF) describes the distribution in stellar masses produced from a burst of star formation. For more than fifty years, the implicit assumption underpinning most areas of research involving the IMF has been…

The stellar initial mass function (IMF) is expressed by $\phi(m) \propto m^{-\alpha}$ with the slope $\alpha$, and known as the poorly-constrained but very important function in studies of star and galaxy formation. There are no sensible…

Astrophysics of Galaxies · Physics 2023-04-13 Shohei Aoyama , Masami Ouchi , Yuichi Harikane

We investigate the origin of a bottom-heavy stellar initial mass function (IMF) recently observed in elliptical galaxies by using chemical evolution models with a non-universal IMF. We adopt the Kroupa IMF with the three slopes (alpha_1,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Kenji Bekki

It is now well-established that the stellar initial mass function (IMF) can be determined from the absorption line spectra of old stellar systems, and this has been used to measure the IMF and its variation across the early-type galaxy…

Astrophysics of Galaxies · Physics 2017-03-22 Charlie Conroy , Pieter van Dokkum , Alexa Villaume

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…

Astrophysics · Physics 2007-05-23 Ian A. Bonnell , Richard B. Larson , Hans Zinnecker

The high-mass slope of the stellar initial mass function (IMF), first measured by E. Salpeter in 1955, appears universal across star-forming environments. Its origin remains a central unsolved problem in astrophysics. Using $getsf$, we…

Astrophysics of Galaxies · Physics 2026-05-22 Guo-Yin Zhang , Alexander Men'shchikov , Jin-Zeng Li

In this work, we derive the stellar initial mass function (IMF) from the superposition of mass distributions of dense cores, generated through gravoturbulent fragmentation of unstable clumps in molecular clouds (MCs) and growing through…

Solar and Stellar Astrophysics · Physics 2015-05-20 Todor Veltchev , Ralf S. Klessen , Paul C. Clark

Several recent observational studies have concluded that the initial mass function (IMF) of stars varies systematically with galaxy properties such as velocity dispersion. In this paper, we investigate the effect of linking the circular…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Sean L. McGee , Ryosuke Goto , Michael L. Balogh

The possibility that the stellar initial mass function (IMF) arises mostly from cloud structure is investigated with fractal Brownian motion (fBm) clouds that have power-law power spectra. An fBm cloud with a realistic projected power…

Astrophysics of Galaxies · Physics 2015-05-19 Mohsen Shadmehri , Bruce G. Elmegreen

An essential component of galaxy formation theory is the stellar initial mass function (IMF), that describes the parent distribution of stellar mass in star forming regions. We present observational evidence in a sample of early-type…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 I. Ferreras , F. La Barbera , R. R. de Carvalho , I. G. de la Rosa , A. Vazdekis , J. Falcon-Barroso , E. Ricciardelli

We obtain constraints on the slope of a universal stellar initial mass function (IMF) over a range of cosmic star-formation histories (SFH) using z=0.1 luminosity densities in the range from 0.2 to 2.2 microns. The age-IMF degeneracy of…

Astrophysics · Physics 2011-05-05 I. K. Baldry , K. Glazebrook

Star formation rates (SFR) larger than 1000 Msun/ yr are observed in extreme star bursts. This leads to the formation of star clusters with masses > 10^6 Msun in which crowding of the pre-stellar cores may lead to a change of the stellar…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Carsten Weidner , Pavel Kroupa , Jan Pflamm-Altenburg

The local stellar mass density is observed to be significantly lower than the value obtained from integrating the cosmic star formation history (SFH), assuming that all the stars formed with a Salpeter initial mass function (IMF). Even…

Astrophysics · Physics 2009-11-13 Stephen M. Wilkins , Andrew M. Hopkins , Neil Trentham , Rita Tojeiro

[abridged] Stars are thought to be formed predominantly in clusters. The clusters are formed following a cluster initial mass function (CMF) similar to the stellar initial mass function (IMF). Both the IMF and the CMF favour low-mass…

Astrophysics of Galaxies · Physics 2012-05-31 M. R. Haas , P. Anders

We present observational evidence of the correlation between the high-mass slope of the stellar initial mass function (IMF) in young star clusters and their stellar surface density, $\sigma_{*}$. When the high-mass end of the IMF is…

Astrophysics of Galaxies · Physics 2023-11-03 Sami Dib

The stellar IMF has been found to be an invariant Salpeter power-law (alpha=2.35) above about 1 Msun, but at the same time a massive star typically has more than one companion. This constrains the possible formation scenarios of massive…

Astrophysics · Physics 2009-11-10 Pavel Kroupa

The stellar initial mass function (IMF) is thought to be bottom-heavy in the cores of the most massive galaxies, with an excess of low mass stars compared to the Milky Way. However, studies of the kinematics of quiescent galaxies at 2<z<5…

Astrophysics of Galaxies · Physics 2024-09-10 Pieter van Dokkum , Charlie Conroy

We summarize recent observational and theoretical progress aimed at understanding the origin of the stellar initial mass function (IMF) with specific focus on galactic star-forming regions. We synthesize data from various efforts to…