English
Related papers

Related papers: The chemical evolution of galaxies with a variable…

200 papers

Much of our knowledge of galaxies comes from analysing the radiation emitted by their stars. It depends on the stellar initial mass function (IMF) describing the distribution of stellar masses when the population formed. Consequently…

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

Recent studies proposed that cosmic rays (CR) are a key ingredient in setting the conditions for star formation, thanks to their ability to alter the thermal and chemical state of dense gas in the UV-shielded cores of molecular clouds. In…

Astrophysics of Galaxies · Physics 2018-02-14 Fabio Fontanot , Gabriella De Lucia , Lizhi Xie , Michaela Hirschmann , Gustavo Bruzual , Stephane Charlot

Star-formation rates (SFRs) of galaxies are commonly calculated by converting the measured Halpha luminosities (L_Halpha) into current SFRs. This conversion is based on a constant initial mass function (IMF) independent of the total SFR. As…

Astrophysics · Physics 2007-09-12 Jan Pflamm-Altenburg , Carsten Weidner , Pavel Kroupa

We consider the present-day photometric and chemical properties of elliptical galaxies, adopting the bimodal star formation scenario of Elbaz, Arnaud & Vangioni-Flam (1995). These models utilise an initial mass function (IMF) biased heavily…

Astrophysics · Physics 2015-06-24 Brad K. Gibson

Over the past years observations of young and populous star clusters have shown that the stellar initial mass function (IMF) can be conveniently described by a two-part power-law with an exponent alpha_2 = 2.3 for stars more massive than…

Astrophysics of Galaxies · Physics 2010-11-10 Carsten Weidner , Jan Pflamm-Altenburg , Pavel Kroupa

We study the origin and cosmic evolution of the mass-metallicity relation (MZR) in star-forming galaxies based on a full, numerical chemical evolution model. The model was designed to match the local MZRs for both gas and stars…

Astrophysics of Galaxies · Physics 2018-09-26 Jianhui Lian , Daniel Thomas , Claudia Maraston

Recent observational and theoretical studies indicate that the stellar initial mass function (IMF) varies systematically with the environment (star formation rate - SFR, metallicity). Although the exact dependence of the IMF on those…

Astrophysics of Galaxies · Physics 2020-04-08 Martyna Chruslinska , Tereza Jerabkova , Gijs Nelemans , Zhiqiang Yan

We present high-resolution simulations of tidal dwarf galaxies (TDG) to investigate their early chemo-dynamical evolution and test their survivability. In this work the simulation setup is introduced and the response of TDGs to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 S. Ploeckinger , G. Hensler , S. Recchi , N. Mitchell , P. Kroupa

Metals enhance the cooling efficiency of molecular clouds, promoting fragmentation. Consequently, increasing the metallicity may boost the formation of low-mass stars. Within the integrated galaxy initial mass function (IGIMF) theory, this…

We test whether the universal initial mass function (UIMF) or the integrated galaxial IMF (IGIMF) can be employed to explain the metallicity distribution (MD) of giants in the Galactic bulge. We make use of a single-zone chemical evolution…

Astrophysics · Physics 2009-11-13 Silvia K. Ballero , Pavel Kroupa , Francesca Matteucci

If all stars form in clusters and both the stars and the clusters follow a power law distribution which favours the creation of low mass objects, then the numerous low mass clusters will be deficient in high mass stars. Therefore, the mass…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 M. R. Haas , P. Anders

Observations with JWST have revealed an unexpected high abundance of bright z>10 galaxy candidates. We explore whether a stellar initial mass function (IMF) that becomes increasingly top-heavy towards higher redshifts and lower gas-phase…

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…

Observations show that galaxies follow a mass-metallicity relation over a wide range of masses. One currently favoured explanation is that less massive galaxies are less able to retain the gas and stellar ejecta and thus may lose the…

Astrophysics · Physics 2008-11-26 J. Koeppen , C. Weidner , P. Kroupa

Recent evidence based independently on spectral line strengths and dynamical modelling point towards a non-universal stellar Initial Mass Function (IMF), probably implying an excess of low-mass stars in elliptical galaxies with a high…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Carsten Weidner , Ignacio Ferreras , Alexandre Vazdekis , Francesco La Barbera

The alpha element to iron peak element ratio, for example [Mg/Fe], is a commonly applied indicator of the galaxy star formation timescale (SFT) since the two groups of elements are mainly produced by different types of supernovae that…

Astrophysics of Galaxies · Physics 2019-12-11 Zhiqiang Yan , Terea Jerabkova , Pavel Kroupa

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

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

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…