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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

Using self-consistent chemodynamical simulations including star formation, supernova feedback, and chemical enrichment, I show the dependence of cosmic star formation and chemical enrichment histories on the initial mass function (IMF). The…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Chiaki Kobayashi

In models of galaxy formation in a hierarchical Universe, elliptical galaxies form through the merging of smaller disk systems. These models yield a number of testable predictions if reliable techniques for determining the relative ages and…

Astrophysics · Physics 2007-05-23 Daniel Thomas , Guinevere Kauffmann

Most structural and evolutionary properties of galaxies strongly rely on the stellar initial mass function (IMF), namely the distribution of the stellar mass formed in each episode of star formation. As the IMF shapes the stellar population…

Astrophysics of Galaxies · Physics 2023-01-31 Jiadong Li , Chao Liu , Zhi-Yu Zhang , Hao Tian , Xiaoting Fu , Jiao Li , Zhi-Qiang Yan

There is substantial evidence that the initial mass function (IMF) may be a function of the local star formation conditions. In particular, the IMF is predicted to flatten with increasing local luminosity density, with the formation of…

Astrophysics · Physics 2009-10-30 Jason A. Taylor

Variations in the stellar initial mass function (IMF) have been invoked to explain the spectroscopic and dynamical properties of early-type galaxies. However, no observations have yet been able to disentangle the physical driver. We analyse…

We describe the use of our chemical evolution model to reproduce the abundance patterns observed in a catalog of elliptical galaxies from the SDSS DR4. The model assumes ellipticals form by fast gas accretion, and suffer a strong burst of…

Astrophysics of Galaxies · Physics 2018-01-10 Carlo Maria De Masi , Francesca Matteucci , Fiorenzo Vincenzo

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

Peaks and lulls in the star formation rate (SFR) over the history of the Galaxy produce plateaux and declines in the present day mass function (PDMF) where the main-sequence lifetime overlaps the age and duration of the SFR variation. These…

Astrophysics · Physics 2009-11-13 Bruce G. Elmegreen , John Scalo

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,…

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

Previous studies of the stellar mean metallicity and [Mg/Fe] values of massive elliptical (E)~galaxies suggest that their stars were formed in a very short timescale which cannot be reconciled with estimates from stellar population…

Astrophysics of Galaxies · Physics 2021-11-03 Zhiqiang Yan , Tereza Jerabkova , Pavel Kroupa

JWST observations have revealed that massive galaxies formed and evolved far faster than predicted by galaxy formation models, with many having already assembled a large mass in stars $\sim12$ billion years ago [1-7]. However, masses of…

The stellar initial mass function (IMF) is a fundamental property in the measurement of stellar masses and galaxy star formation histories. In this work we focus on the most massive galaxies in the nearby universe…

Astrophysics of Galaxies · Physics 2022-06-29 Meng Gu , Jenny Greene , Andrew B. Newman , Christina Kreisch , Matthew Quenneville , Chung-Pei Ma , John P. Blakeslee

Growing evidence in recent years suggests a systematic variation of the stellar initial mass function (IMF), being top-heavy for starburst galaxies and possibly bottom-heavy for massive ellipticals. Galaxy chemical evolution simulations…

Astrophysics of Galaxies · Physics 2019-09-11 Zhiqiang Yan , Tereza Jerabkova , Pavel Kroupa , Alejandro Vazdekis

In the local Universe, massive early-type galaxies exhibit enhanced [Mg/Fe] ratios, which has been traditionally interpreted as the result of a rapid ($\tau \lesssim 1$ Gyr) collapse. However, recent claims of a non-universal, steep initial…

Astrophysics of Galaxies · Physics 2015-12-16 I. Martín-Navarro

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

We examine the cosmic evolution of a stellar initial mass function (IMF) in galaxies that varies with the Jeans mass in the interstellar medium, paying particular attention to the K-band stellar mass to light ratio (M/L_K) of present-epoch…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Desika Narayanan , Romeel Davé

We derive a semi-empirical galactic initial mass function (IMF) from observational constraints. We assume that the star formation rate in a galaxy can be expressed as the product of the IMF, $\psi (m)$, which is a smooth function of mass…

Astrophysics of Galaxies · Physics 2015-05-20 Antonio Parravano , Christopher F. McKee , David J. Hollenbach

Semi-analytical evolution models of galaxies are a useful and computationally inexpensive tool for fast assessment of individual properties and their evolution. In this work, specifically the influence of a metallicity and star-formation…

Astrophysics of Galaxies · Physics 2026-04-23 Lukas Hof , Pavel Kroupa , Gerhard Hensler , Jan Pflamm-Altenburg