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The stellar initial mass function (IMF) is a fundamental property of star formation, offering key insight into the physics driving the process as well as informing our understanding of stellar populations, their by-products, and their…

Astrophysics of Galaxies · Physics 2019-03-14 M. W. Hosek , J. R. Lu , M. Andersen , T. Do , D. Kim , N. Z. Rui , P. Boyle , B. F. Williams , S. Chakrabarti , R. L. Beaton

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

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

Using very deep, high spectral resolution data from the SAMI Integral Field Spectrograph we study the stellar population properties of a sample of dwarf galaxies in the Fornax Cluster, down to a stellar mass of $10^{7}$ M$_{\odot}$, which…

The observed stellar initial mass function (IMF) appears to vary, becoming bottom-heavy in the centres of the most massive, metal-rich early-type galaxies. It is still unclear what physical processes might cause this IMF variation. In this…

Astrophysics of Galaxies · Physics 2020-10-07 Timothy A. Davis , Freeke van de Voort

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…

We summarize recent observational and theoretical progress aimed at understanding the origin of the stellar initial mass function (IMF) with specific focus on galactic star-forming regions. We synthesize data from various efforts to…

Recent spectroscopic explorations of large Galactic stellar samples stars have revealed the existence of red giants with [$\alpha$/Fe] ratios that are anomalously high, given their relatively young ages. We revisit the GALAH DR3 survey to…

Solar and Stellar Astrophysics · Physics 2022-12-21 S. Borisov , N. Prantzos , C. Charbonnel

The chemical enrichment and stellar abundance ratios of galaxies which form in a hierarchical clustering scheme are calculated. For this purpose I adopt the star formation histories (SFH) as they are delivered by semi-analytic models in…

Astrophysics · Physics 2009-10-31 D. Thomas

(abridged) The case can be made for a rather universal stellar IMF form that can be approximated by a two-part power-law function in the stellar regime. However, there exists a possible hint for a systematic variation with metallicity. A…

Astrophysics · Physics 2007-05-23 Pavel Kroupa

We test the integrated galactic initial mass function (IGIMF) on the chemical evolution of 16 ultra-faint dwarf (UFD) galaxies discussing in detail the results obtained for three of them: Bo\"otes I, Bo\"otes II and Canes Venatici I, taken…

Astrophysics of Galaxies · Physics 2020-02-28 E. Lacchin , F. Matteucci , F. Vincenzo , M. Palla

We present constraints on the stellar initial mass function (IMF) in two ultra-faint dwarf (UFD) galaxies, Hercules and Leo IV, based on deep HST/ACS imaging. The Hercules and Leo IV galaxies are extremely low luminosity (M_V = -6.2, -5.5),…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 M. Geha , T. M. Brown , J. Tumlinson , J. Kalirai , J. D. Simon , E. Kirby , D. VandenBerg , R. M. Munoz , R. Avila , P. Guhathakurta , H. Ferguson

Samples of early-type galaxies show a correlation between stellar velocity dispersion and the stellar initial mass function (IMF) as inferred from gravity-sensitive absorption lines in the galaxies' central regions. To search for spatial…

Astrophysics of Galaxies · Physics 2016-04-20 Nicholas J. McConnell , Jessica R. Lu , Andrew W. Mann

The stellar initial mass function (IMF) is a key parameter to study galaxy evolution. Here we measure the IMF mass normalization for a sample of 68 field galaxies in the redshift range 0.7 to 0.9 within the Extended Groth Strip. To do this…

Astrophysics of Galaxies · Physics 2014-06-19 Shravan Shetty , Michele Cappellari

Over the past years observations of young and populous star clusters have shown that the stellar IMF appears to be an invariant featureless Salpeter power-law with an exponent alpha=2.35 for stars more massive than a few Msun. A consensus…

Astrophysics · Physics 2009-11-10 Pavel Kroupa , Carsten Weidner

We present a study of the early build-up of dust in high redshift galaxies. The study is based on the analysis of 38 Damped Ly alpha systems (DLAs) for which we derive the fraction of iron atoms in dust form, f_{Fe}. The sample is…

Astrophysics · Physics 2009-11-10 Giovanni Vladilo

Using Chandra X-ray observations of young, post-merger elliptical galaxies, we present X-ray characteristics of age-related observational results, by comparing with typical old elliptical galaxies in terms of metal abundances in the hot…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Dong-Woo Kim , Giuseppina Fabbiano , Antonio Pipino

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

The overabundance of Mg relative to Fe, observed in the nuclei of bright ellipticals, and its increase with galactic mass, poses a serious problem for all current models of galaxy formation. Here we improve on the one-zone chemical…

Astrophysics · Physics 2009-11-13 A. Pipino , J. Silk , F. Matteucci

Observational and theoretical arguments increasingly suggest that the initial mass function (IMF) of stars may depend systematically on environment, yet most galaxy formation models to date assume a universal IMF. Here we investigate…

Astrophysics of Galaxies · Physics 2018-11-26 Thales A. Gutcke , Volker Springel
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