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Related papers: Deviations from the universal Initial Mass Functio…

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The stellar initial mas function (IMF) has been described as being invariant, bottom heavy or top-heavy in extremely dense star burst conditions. To provide usable observable diagnostic we calculate redshift dependent spectral energy…

Astrophysics of Galaxies · Physics 2018-01-04 Tereza Jerabkova , Pavel Kroupa , Joerg Dabringhausen , Michael Hilker , Kenji Bekki

One of the key observations regarding the stellar initial mass function (IMF) is its near-universality in the Milky Way (MW), which provides a powerful way to constrain different star formation models that predict the IMF. However, those…

Astrophysics of Galaxies · Physics 2018-04-25 David Guszejnov , Philip F. Hopkins , Xiangcheng Ma

The current knowledge on the stellar IMF is documented. It appears to become top-heavy when the star-formation rate density surpasses about 0.1Msun/(yr pc^3) on a pc scale and it may become increasingly bottom-heavy with increasing…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Pavel Kroupa , Carsten Weidner , Jan Pflamm-Altenburg , Ingo Thies , Joerg Dabringhausen , Michael Marks , Thomas Maschberger

I review efforts to determine the form and any lower limit to the initial mass function in the Galactic disk, using observations of low-mass stars and brown dwarfs in the field, young clusters and star forming regions. I focus on the…

Solar and Stellar Astrophysics · Physics 2015-06-05 R. D. Jeffries

We examine variations of the stellar initial mass function (IMF) in extreme environments within the formalism derived by Hennebelle \& Chabrier. We focus on conditions encountered in progenitors of massive early type galaxies and starburst…

Astrophysics of Galaxies · Physics 2015-06-23 G. Chabrier , P. Hennebelle , P. Charlot

Theoretical and indirect observational evidences suggest that stellar initial mass function (IMF) increases with redshift. On the other hand star formation rates (SFR) may be as high as 100 $M_{\odot}$ yr$^{-1}$ in star burst galaxies.…

Astrophysics of Galaxies · Physics 2015-08-06 Tanuka Chattopadhyay , Tuli De , Bharat Warlu , Asis Kumar Chattopadhyay

A wealth of observations recently challenged the notion of a universal stellar initial mass function (IMF) by showing evidences in favour of a variability of this statistical indicator as a function of galaxy properties. I present…

Astrophysics of Galaxies · Physics 2020-06-17 Fabio Fontanot

The stellar initial-mass function (IMF) represents a fundamental quantity in astrophysics and cosmology, describing the mass distribution of stars from low to very-high masses. It is intimately linked to a wide variety of topics, including…

High Energy Astrophysical Phenomena · Physics 2024-09-17 Francesco Gabrielli , Lumen Boco , Giancarlo Ghirlanda , Om Sharan Salafia , Ruben Salvaterra , Mario Spera , Andrea Lapi

The functional form of the galaxy-wide stellar initial mass function is of fundamental importance for understanding galaxies. So far this stellar initial mass function has been assumed to be identical to the IMF observed directly in star…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-11 Jan Pflamm-Altenburg , Carsten Weidner , Pavel Kroupa

Observations indicate that the central portions of the Present-Day Prestellar Core Mass Function (CMF) and the Stellar Initial Mass Function (IMF) both have approximately log-normal shapes, but that the CMF is displaced to higher mass than…

Solar and Stellar Astrophysics · Physics 2013-06-07 K. Holman , S. K. Walch , S. P. Goodwin , A. P. Whitworth

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

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 hypothesis of a universal initial mass function (IMF) -- motivated by observations in nearby stellar systems -- has been recently challenged by the discovery of a systematic variation of the IMF with the central velocity dispersion,…

Analyses of strong gravitational lenses, galaxy-scale kinematics, and absorption line stellar population synthesis (SPS) have all concluded that the stellar initial mass function (IMF) varies within the massive early-type galaxy (ETG)…

Astrophysics of Galaxies · Physics 2017-11-29 Alexa Villaume , Jean Brodie , Charlie Conroy , Aaron J. Romanowsky , Pieter van Dokkum

The stellar initial mass function (IMF) is fundamental for many areas of astrophysics, but its origin remains poorly understood. It may be inherited from the core mass function (CMF) or arise as a result of more chaotic, competitive…

Astrophysics of Galaxies · Physics 2021-08-04 Theo J. O'Neill , Giuliana Cosentino , Jonathan C. Tan , Yu Cheng , Mengyao Liu

The expected metal enrichment of the intra-cluster medium (ICM) and the partition of metals between cluster galaxies and the hot ICM depends on the stellar Initial Mass Function (IMF). The choice of the IMF in simulations of clusters has…

Astrophysics · Physics 2007-05-23 L. Portinari

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

Our understanding of stellar systems depends on the adopted interpretation of the IMF, phi(m). Unfortunately, there is not a common interpretation of the IMF, which leads to different methodologies and diverging analysis of observational…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-02 Miguel Cervino , Carlos Romann-Zuniga , Valentina Luridiana , Amelia Bayo , Nestor Sanchez , Enrique Perez

The spectral absorption lines in early-type galaxies contain a wealth of information regarding the detailed abundance pattern, star formation history, and stellar initial mass function (IMF) of the underlying stellar population. Using our…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Charlie Conroy , Pieter van Dokkum

Context: Stars form in the cold dense cores of interstellar molecular clouds and the detailed knowledge of the spectrum of masses of such cores is clearly a key for the understanding of the origin of the IMF. To date, observations have…

Astrophysics · Physics 2011-06-21 J. Alves , M. Lombardi , C. Lada