相关论文: The Initial Mass Function and its Variation

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…

We present a method for investigating variations in the upper end of the stellar Initial Mass Function (IMF) by probing the production rate of ionizing photons in unresolved, compact star clusters with ages <~10 Myr and with different…

The initial mass function (IMF) is a construct that describes the distribution of stellar masses for a newly formed population of stars. It is a fundamental element underlying all of star and galaxy formation, and has been the subject of…

The recent finding that the IGIMF (integrated galaxial initial stellar mass function) composed of all newly formed stars in all young star clusters has, in dependence of the SFR, a steeper slope in the high mass regime than the underlying…

A robust stellar initial mass function (IMF) is crucial in any studies related to star formation. However, the direct measurement of the stellar IMF is confined to the local universe, limited by the resolving power of telescopes. Recently,…

The dichotomy between a universal mass function (IMF) and a variable IMF which depends on local physical parameters characterises observational and theoretical stellar astronomy. In this contribution the available distributions of…

The starburst IMF is probably as much of theoretical interest and practical relevance as it is a subject of observational controversy. In this conference paper we review the most common methods (star counts, dynamical masses, and line…

The long-standing assumption that the stellar initial mass function (IMF) is universal has recently been challenged by a number of observations. Several studies have shown that a "heavy" IMF (e.g., with a Salpeter-like abundance of low mass…

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…

Stars form in clustered environments, but how they form when the available resources are shared is still not well understood. A related question is whether the IMF is in fact universal across galactic environments, a galactic initial mass…

We introduce a new method to measure the dispersion of mmax values of star clusters and show that the observed sample of mmax is inconsistent with random sampling from an universal stellar initial mass function (IMF) at a 99.9% confidence…

Star formation rates (SFR) larger than 1000 Msun/ yr are observed in extreme star bursts. This leads to the formation of star clusters with masses > 10^6 Msun in which crowding of the pre-stellar cores may lead to a change of the stellar…

A stochastic model of fragmentation of molecular clouds has been developed for studying the resulting Initial Mass Function (IMF) where the number of fragments, inter-occurrence time of fragmentation, masses and velocities of the fragments…

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…

The evolution of the global stellar mass function (MF) of star clusters is studied based on a large set of N-body simulations of clusters with a range of initial masses, initial concentrations, in circular or elliptical orbits in different…

The unexpected high incidence of carbon-enhanced, s-process enriched unevolved stars amongst extremely metal-poor stars in the halo provides a significant constraint on the Initial Mass Function (IMF) in the early Galaxy. We argue that…

Fifty years after Ed Salpeter's seminal paper, tremendous progress both on the observational and theoretical sides allow a fairly accurate determination of the Galactic IMF not only down to the hydrogen-burning limit but into the brown…

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…

A method is presented here for investigating variations in the upper end of the stellar Initial Mass Function (IMF) by probing the production rate of ionizing photons in unresolved, compact star clusters with ages<10 Myr and covering a…

The theory for the formation of the first population of stars (Pop III) predicts an initial mass function (IMF) dominated by high-mass stars, in contrast to the present-day IMF, which tends to yield mostly stars with masses less than 1…