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Related papers: Initial mass function variability from the integra…

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The study of young stellar populations has revealed that most stars are in binary or higher order multiple systems. In this study the influence on the stellar initial mass function (IMF) of large quantities of unresolved multiple massive…

Astrophysics · Physics 2009-11-13 C. Weidner , P. Kroupa , T. Maschberger

The solar neighbourhood is populated by nearby, young moving groups (NYMGs) of stars that are candidates to be remnants of individual stellar clusters and associations, currently dispersing in the galactic disc. To derive the initial mass…

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

We analyse intermediate-resolution VLT FLAMES/Giraffe spectra of six ultra-compact dwarf (UCD) galaxies in the Fornax cluster. We obtained velocity dispersions and stellar population properties by full spectral fitting against PEGASE.HR…

Astrophysics · Physics 2009-11-13 Igor Chilingarian , Veronique Cayatte , Gilles Bergond

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

Some ultra-compact dwarf galaxies have large dynamical mass to light (M/L) ratios and also appear to contain an overabundance of LMXB sources, and some Milky Way globular clusters have a low concentration and appear to have a deficit of…

Astrophysics of Galaxies · Physics 2020-03-18 Pavel Kroupa

Based on MUSE integral-field data we present evidence for a radial variation at the low-mass end of the stellar initial-mass function (IMF) in the central regions of the giant early-type galaxy NGC4486 (M87). We used state-of-the-art…

Astrophysics of Galaxies · Physics 2018-05-16 Marc Sarzi , Chiara Spiniello , Francesco La Barbera , Davor Krajnović , Remco van den Bosch

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

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 stellar initial mass function (IMF) plays a crucial role in determining the number of surviving stars in galaxies, the chemical composition of the interstellar medium, and the distribution of light in galaxies. A key unsolved question…

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 optical spectral region of spectra of 1000 stars searching for IMF-sensitive features to constrain the low-mass end of the initial mass function (IMF) slope in elliptical galaxies. We use the MILES stellar library in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Chiara Spiniello , Scott Trager , Léon V. E. Koopmans , Charlie Conroy

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

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

Using integral field spectroscopy, we demonstrate that gravity-sensitive absorption features in the zJ-band (0.9--1.35 \micron) can constrain the low-mass stellar initial mass function (IMF) in the cores of two elliptical galaxies, M85 and…

Astrophysics of Galaxies · Physics 2019-05-01 R. Elliot Meyer , Suresh Sivanandam , Dae-Sik Moon

A universal stellar initial mass function (IMF) should not be expected from theoretical models of star formation, but little conclusive observational evidence for a variable IMF has been uncovered. In this paper, a parameterization of the…

Astrophysics of Galaxies · Physics 2022-06-01 Albert Sneppen , Charles L. Steinhardt , Hagan Hensley , Adam S. Jermyn , Basel Mostafa , John R. Weaver

The production rate of ionizing photons in young < 8 Myr, unresolved stellar clusters in the nearby irregular galaxy NGC 4214 is probed using multi-wavelength Hubble Space Telescope WFC3 data. We normalize the ionizing photon rate by the…

We present a new technique for the determination of the low-mass slope ($\alpha_1$; $M_* < 0.5 M_{\odot}$) of the present day stellar mass function (PDMF) using the pixel space fitting of integrated light spectra. It can be used to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Nikolay Podorvanyuk , Igor Chilingarian , Ivan Katkov

Recent work suggested that the variation of the initial mass function (IMF) of stars depends on the physical conditions, notably, the metallicity and gas density. We investigated the properties of two clusters, namely the main cluster (MC)…

Astrophysics of Galaxies · Physics 2024-04-11 Marie Zinnkann , Henriette Wirth , Pavel Kroupa

Many recent works have attempted to constrain the stellar initial mass function (IMF) inside massive clusters by comparing their dynamical mass estimates to the measured light. These studies have come to different conclusions, with some…

Astrophysics · Physics 2009-11-11 N. Bastian , S. P. Goodwin