相关论文: Confidence Limits of Evolutionary Synthesis Models

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…

It is frequently debated in literature whether a "standard" Initial Mass Function (IMF) - meaning an IMF of the kind usually adopted to explain the chemical evolution in the local Solar Neighbourhood - can account for the observed metal…

Binary population synthesis provides a direct way of studying the effects of different choices of binary evolution models and initial parameter distributions on present-day binary compact merger populations, which can then be compared to…

We obtain constraints on the slope of a universal stellar initial mass function (IMF) over a range of cosmic star-formation histories (SFH) using z=0.1 luminosity densities in the range from 0.2 to 2.2 microns. The age-IMF degeneracy of…

This paper studies the propagation of finite-sample uncertainty under nonlinear transformations commonly used in statistical decision systems. In particular, we consider process capability indices, which are widely used in manufacturing…

We present results from Tree+SPH simulations of a galaxy cluster, aimed at studying the metal enrichment of the intra--cluster medium (ICM). The simulation code includes a fairly advanced treatment of star formation, as well as the release…

Evolutionary synthesis models are the prime method to construct models of stellar populations, and to derive physical parameters from observations. One of the assumptions for such models so far has been the time-independence of the stellar…

Diffusion models have become the go-to method for many generative tasks, particularly for image-to-image generation tasks such as super-resolution and inpainting. Current diffusion-based methods do not provide statistical guarantees…

During the last few years, the Geneva stellar evolution group has released new grids of stellar models, including the effect of rotation and with updated physical inputs (Ekstr\"om et al. 2012; Georgy et al. 2013a,b). To ease the comparison…

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…

In this work we explore the effects of adopting an initial mass function (IMF) variable in time on the chemical evolution of the Galaxy. In order to do that we adopt a chemical evolution model which assumes two main infall episodes for the…

The effects of the orbital diffusion of stars and clusters on the galactic abundance gradient have been modelled. For a single generation of field stars, the results confirm previous analyses based upon the assumption of a linear gradient…

We review recent high spatial resolution millimeter continuum and spectral line observations of (proto-)cluster regions. These observations reveal that the mass distribution of prestellar cores is consistent with the initial mass function…

The stellar IMF has been found to be an invariant Salpeter power-law (alpha=2.35) above about 1 Msun, but at the same time a massive star typically has more than one companion. This constrains the possible formation scenarios of massive…

Recent results on the non-universality of the Initial Mass Function (IMF) have shown strong evidence of IMF variations with galaxy velocity dispersion, with a corresponding impact on other stellar population parameters, line indices and…

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…

Few topics in astronomy initiate such vigorous discussion as whether or not the initial mass function (IMF) of stars is universal, or instead sensitive to the initial conditions of star formation. The distinction is of critical importance:…

The highest-mass stars have the lowest frequency in the stellar IMF, and they are also the most easily observed stars. Thus, the counting statistics for OB stars provide important tests for the fundamental nature and quantitative parameters…

Low-mass stars (M<0.4Msun) are thought to comprise the bulk of the stellar mass of galaxies but they constitute only of order a percent of the bolometric luminosity of an old stellar population. Directly estimating the number of low-mass…

The integrated galaxial initial mass function (IGIMF) is the relevant distribution function containing the information on the distribution of stellar remnants, the number of supernovae and the chemical enrichment history of a galaxy. Since…