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Related papers: Upper End IMF Variations Deduced from HI-Selected …

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Ultra compact dwarf galaxies (UCDs) are dense stellar systems at the border between massive star-clusters and small galaxies. Their on average high optical mass-to-light (M/L) ratio cannot be explained by stellar populations with the…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-19 Jörg Dabringhausen , Pavel Kroupa

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 review recent determinations of the present day and initial mass functions in various components of the Galaxy, disk, spheroid, young and globular clusters. As a general feature, the IMF is well described by a power-law form for $m\ga 1…

Astrophysics · Physics 2008-11-26 Gilles Chabrier

Observations have not yielded convincing results concerning the form of the stellar initial mass function (IMF) or its variations in space and time, so it is proposed that theoretical models may provide useful guidance. Several classes of…

Astrophysics · Physics 2009-09-25 John Scalo

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

Observations and theory of the IMF are briefly reviewed. Slight variations have been observed, although they are difficult to prove unambiguously. Most detailed theoretical models reproduce the IMF, but because they use different…

Astrophysics · Physics 2007-05-23 Bruce G. Elmegreen

We have undertaken the largest systematic study of the high-mass stellar initial mass function (IMF) to date using the optical color-magnitude diagrams (CMDs) of 85 resolved, young (4 Myr < t < 25 Myr), intermediate mass star clusters…

(abridged) The {stellar IMF} has been found to be essentially invariant. While some apparent differences are seen, the uncertainties inherent to this game do not allow a firm conclusion to be made that the IMF varies systematically with…

Astrophysics · Physics 2015-11-11 Pavel Kroupa , Carsten Weidner

Statistical sampling from the stellar initial mass function (IMF) for all star-forming regions in the Galaxy would lead to the prediction of ~1000 Msun stars unless there is a rapid turn-down in the IMF beyond several hundred solar masses.…

Astrophysics · Physics 2009-10-31 Bruce G. Elmegreen

We show data from the Survey of Ionization in Neutral Gas Galaxies (SINGG) and Survey of Ultraviolet emission in Neutral Gas Galaxies (SUNGG) which survey the star formation properties of HI selected galaxies as traced by H-alpha and…

Astrophysics · Physics 2009-11-13 Gerhardt R. Meurer , O. Ivy Wong , Daniel J. Hanish

The recently inferred variations in the stellar initial mass function (IMF) among local high-mass early-type galaxies may require a reinterpretation of observations of galaxy populations and may have important consequences for the…

Astrophysics of Galaxies · Physics 2018-07-17 Christopher Barber , Robert A. Crain , Joop Schaye

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

Recent results form the James Webb Space Telescope (JWST) report space densities for bright and massive galaxies at z>7 that far exceed expectations of theoretical models of galaxy formation, prompting a revision of our understanding of the…

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

Large high-quality samples of HII regions and their parent Giant Molecular Clouds (GMC) are now available for local galaxies. It is therefore possible to investigate links between the CO and H$\alpha$ luminosity functions and whether…

Astrophysics of Galaxies · Physics 2026-04-29 Jonathan Braine , Edvige Corbelli

We present a uniform analysis of the stellar initial mass function (IMF) from integrated light spectroscopy of 15 compact stellar systems (11 globular clusters in M31 and 4 ultra compact dwarfs in the Virgo cluster, UCDs) and two brightest…

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

I present a comparison between published dynamical (ATLAS3D) and spectroscopic (Conroy & van Dokkum) constraints on the stellar initial mass function (IMF) in early-type galaxies, using the 34 galaxies in common between the two works. Both…

Astrophysics of Galaxies · Physics 2015-06-19 Russell J. Smith

Using new UV magnitudes for a sample of early-type galaxies, ETGs, with published stellar mass-to-light ratios, Upsilon_*, we find a correlation between UV color and Upsilon_* that is tighter than those previously identified between…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Dennis Zaritsky , Armando Gil de Paz , Alexandre Y. K. Bouquin

We extend our initial study of the connection between the UV colour of galaxies and both the inferred stellar mass-to-light ratio, $\Upsilon_*$, and a mass-to-light ratio referenced to Salpeter initial mass function (IMF) models of the same…

Astrophysics of Galaxies · Physics 2015-06-23 Dennis Zaritsky , Armando Gil de Paz , Alexandre Y. K. Bouquin