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Related papers: Variations in the initial mass function in early-t…

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Deviations from a universal, MW-like, Stellar Initial Mass Function (IMF) have been reported for distant galaxies, although the physical reason behind the observed variations is still matter of ongoing debate. In this paper, we present an…

Astrophysics of Galaxies · Physics 2015-06-19 Fabio Fontanot

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 investigated a volume-limited sample of LAMOST main-sequence stars with masses from 0.25 to 1 $M_{\odot}$ and distances of 150-350 pc to explore how the stellar initial mass function (IMF) varies with metallicity. We corrected the…

Solar and Stellar Astrophysics · Physics 2025-11-07 Dan Qiu , Chao Liu , Jennifer A. Johnson , Jiadong Li , Bo Zhang

We here present the first spatially-resolved study of the IMF in external galaxies derived using a dynamical tracer of the mass-to-light ratio. We use the kinematics of relaxed molecular gas discs in seven early-type galaxies (ETGs)…

Astrophysics of Galaxies · Physics 2016-09-21 Timothy A. Davis , Richard M. McDermid

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

One of the most robust observations of the stellar initial mass function (IMF) is its near-universality in the Milky Way and neighboring galaxies. But recent observations of early-type galaxies can be interpreted to imply a bottom-heavy…

Astrophysics of Galaxies · Physics 2019-03-26 David Guszejnov , Philip F. Hopkins , Andrew S. Graus

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

The stellar initial mass function (IMF) is believed to be non-universal among early-type galaxies (ETGs). Parameterizing the IMF with the so-called IMF mismatch parameter $\alpha_{\rm IMF}$, which is a measure of the stellar mass-to-light…

Astrophysics of Galaxies · Physics 2020-10-14 Carlo Nipoti , Carlo Cannarozzo , Francesco Calura , Alessandro Sonnenfeld , Tommaso Treu

Few topics in astronomy initiate such vigorous discussion as whether or not the initial mass function (IMF) of stars is universal, or instead sensitive to the initial conditions of star formation. The distinction is of critical importance:…

Solar and Stellar Astrophysics · Physics 2010-12-01 Nate Bastian , Kevin R. Covey , Michael R. Meyer

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

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 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…

Using the final MaNGA sample of 10K galaxies, we investigate the dark matter fraction $f_{\rm DM}$ within one half-light radius $R_{\rm e}$ for about 6K galaxies with good kinematics spanning a wide range of morphologies and stellar…

Astrophysics of Galaxies · Physics 2024-04-24 Shengdong Lu , Kai Zhu , Michele Cappellari , Ran Li , Shude Mao , Dandan Xu

Observational studies are showing that the galaxy-wide stellar initial mass function are top-heavy in galaxies with high star-formation rates (SFRs). Calculating the integrated galactic stellar initial mass function (IGIMF) as a function of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Carsten Weidner , Pavel Kroupa , Jan Pflamm-Altenburg , Alexandre Vazdekis

In our previous work, we derive the CR-IGIMF: a new scenario for a variable stellar initial mass function (IMF), which combines numerical results on the role played by cosmic rays in setting the thermal state of star forming gas, with the…

Cosmological simulations are reaching the resolution necessary to study ultra-faint dwarf galaxies. Observations indicate that in small populations, the stellar initial mass function (IMF) is not fully populated; rather, stars are sampled…

Astrophysics of Galaxies · Physics 2020-02-24 Elaad Applebaum , Alyson M. Brooks , Thomas R. Quinn , Charlotte R. Christensen

We explore the assumption, widely used in many astrophysical calculations, that the stellar initial mass function (IMF) is universal across all galaxies. By considering both a canonical Salpeter-like IMF and a non-universal IMF, we are able…

Spatially resolved kinematics of nearby galaxies has shown that the ratio of dynamical- to stellar population-based estimates of the mass of a galaxy ($M_*^{\rm JAM}/M_*$) correlates with $\sigma_e$, if $M_*$ is estimated using the same IMF…

A number of recent studies have proposed that the stellar initial mass function (IMF) of early type galaxies varies systematically as a function of galaxy mass, with higher mass galaxies having bottom heavy IMFs. These bottom heavy IMFs…

In this paper, basic observational properties of elliptical galaxies such as the integrated spectra, the chemical abundances and the enhancement of $\alpha$-elements inferred from broad-band colors and line strength indices $Mg_2$ and $< Fe…

Astrophysics · Physics 2009-09-25 C. Chiosi , A. Bressan , L. Portinari , R. Tantalo