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Related papers: IMF biases and how to correct them

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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…

(shortened) In this contribution an average or Galactic-field IMF is defined, stressing that there is evidence for a change in the power-law index at only two masses: near 0.5 Msun and 0.08 Msun. Using this supposed universal IMF, the…

Astrophysics · Physics 2011-09-29 Pavel Kroupa

We present near-infrared $J$, $H$, and $K$ images of four embedded stellar clusters in the Galaxy. We find a significant fraction of pre-main-sequence stars present in at least one of the clusters. For the clusters dominated by…

Astrophysics · Physics 2008-11-26 A. Leistra , A. Cotera , J. Liebert

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

Mass measurements and absorption line studies indicate that the stellar initial mass function (IMF) is bottom-heavy in the central regions of many early-type galaxies, with an excess of low mass stars compared to the IMF of the Milky Way.…

Astrophysics of Galaxies · Physics 2021-12-22 Pieter van Dokkum , Charlie Conroy

In this work, we want to find out if the IMF can be determined from colour images, integrated colours, or mass-to-light ratios, especially at high redshift, where galaxies cannot be resolved into individual stars, which would enable us to…

Astrophysics · Physics 2008-11-26 P. Westera , M. Samland , S. J. Kautsch , R. Buser , K. Ammon

Research on the high-mass end of the initial mass function (IMF) has been limited due to a scarcity of samples. Recently, Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), as the most efficient spectroscopic telescope, has…

Astrophysics of Galaxies · Physics 2025-05-21 Qida Li , Jianping Xiong , Zhenwei Li , Dan Qiu , Chao Liu , Zhanwen Han , Xuefei Chen

The birth of stars and the formation of galaxies are cornerstones of modern astrophysics. While much is known about how galaxies globally and their stars individually form and evolve, one fundamental property that affects both remains…

Astrophysics of Galaxies · Physics 2019-02-20 A. M. Hopkins

The dependence of the stellar initial mass function (IMF) on star-formation environment, particularly at low metallicities and high redshifts, remains poorly constrained. Ultra-faint dwarf galaxies (UFDs) are local fossils of high-redshift…

The debate about the universality of the stellar initial mass function (IMF) revolves around two competing lines of evidence. While measurements in the Milky Way, an archetypal spiral galaxy, seem to support an invariant IMF, the observed…

Recent observational evidence for initial mass function (IMF) variations in massive quiescent galaxies at $z = 0$ challenges the long-established paradigm of a universal IMF. While a few theoretical models relate the IMF to birth cloud…

Astrophysics of Galaxies · Physics 2017-08-30 Kirsten Blancato , Shy Genel , Greg Bryan

It is usually assumed that the stellar initial mass function (IMF) takes a universal form and that there exists a direct mapping between this and the distribution of natal core masses (the core mass function, CMF). The IMF and CMF have been…

It has been shown before that the high mass-to-light ratios of ultra compact dwarf galaxies (UCDs) can be explained if their stellar initial mass function (IMF) was top-heavy, i.e. that the IMF was skewed towards high mass stars. In this…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jörg Dabringhausen , Pavel Kroupa , Jan Pflamm-Altenburg , Steffen Mieske

The dichotomy between a universal mass function (IMF) and a variable IMF which depends on local physical parameters characterises observational and theoretical stellar astronomy. In this contribution the available distributions of…

Astrophysics · Physics 2011-09-20 Lorenzo Zaninetti

It has frequently been suggested that the stellar IMF in galaxies was top-heavy at early times. This would be plausible physically if the IMF depends on a mass scale such as the Jeans mass that was higher at earlier times because of the…

Astrophysics · Physics 2009-10-30 Richard B. Larson

We use recent microlensing observations toward the central bulge of the Galaxy to probe the overall stellar plus brown dwarf initial mass function (IMF) in these regions well within the brown dwarf domain. We find that the IMF is consistent…

Astrophysics of Galaxies · Physics 2023-02-22 Gilles Chabrier , Romain Lenoble

The stellar initial mass function (IMF) integrated over an entire galaxy is an integral over all separate star-formation events. Since most stars form in star clusters with different masses the integrated IMF becomes an integral of the…

Astrophysics · Physics 2007-05-23 C. Weidner , P. Kroupa

Recent studies seem to suggest that the stellar initial mass function (IMF) in early-type galaxies might be different from a classical Kroupa or Chabrier IMF, i.e. contain a larger fraction of the total mass in low-mass stars. From a…

Astrophysics of Galaxies · Physics 2016-08-05 Clio Bertelli Motta , Paul C. Clark , Simon C. O. Glover , Ralf S. Klessen , Anna Pasquali

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…

High Energy Astrophysical Phenomena · Physics 2015-10-07 S. E. de Mink , K. Belczynski

Crucial for star formation is the interplay between gravity and turbulence. The observed cloud virial parameter, $\alpha_{\mathrm{vir}}$, which is the ratio of twice the turbulent kinetic energy to the gravitational energy, is found to vary…

Astrophysics of Galaxies · Physics 2025-01-07 Sajay Sunny Mathew , Christoph Federrath , Amit Seta