Related papers: Steeper, Flatter, or Just "Salpeter"? Evidence fro…
We have used a suite of simplified spectrophotometric spiral galaxy evolution models to argue that there are substantial variations in stellar mass-to-light ratios (M/Ls) within and among galaxies, amounting to factors of between 3 and 7 in…
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…
When calculating IMFs for young clusters, one has to take into account that (a) most massive stars are born in multiple systems (b) most IMFs are derived from data that cannot resolve such systems, and (c) multiple chance superpositions…
The stellar initial mass function (IMF) in star clusters is reviewed. Uncertainties in the observations are emphasized. We suggest there is a distinct possibility that cluster IMFs vary systematically with density or pressure. Dense…
There are various ways of measuring the slope of the upper end of the IMF. Arguably the most direct of these is to place stars on the H-R diagram and compare their positions with stellar evolutionary models. Even so, the masses one infers…
We present deep spectroscopy with the Keck telescope of eight galaxies in the luminous X-ray cluster MS1054-03 at z=0.83. The data are combined with imaging observations from the Hubble Space Telescope (HST). The spectroscopic data are used…
The stellar initial mass function (IMF) is predicted to depend upon the temperature of gas in star-forming molecular clouds. The introduction of an additional parameter, $T_{IMF}$ , into photometric template fitting, allows galaxies to be…
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…
We present gravitational lens models for 20 strong gravitational lens systems observed as part of the Sloan WFC Edge-on Late-type Lens Survey (SWELLS) project. Fifteen of the lenses are taken from paper I while five are newly discovered…
The stellar initial mass function (IMF) integrated over an entire galaxy is an integral over all separate star-formation events. Since most stars form in star clusters with different masses the integrated IMF becomes an integral of the…
The stellar initial mass function is of great significance for the study of star formation and galactic structure. Observations indicate that the IMF follows a power-law form. This work derived that when the expected number of stars formed…
We present composite 3.6 and 4.5 micron luminosity functions for cluster galaxies measured from the Spitzer Deep, Wide-Field Survey (SDWFS) for 0.3<z<2. We compare the evolution of m* for these luminosity functions to models for passively…
A survey of results concerning the IMF derived from star counts is presented, including work up to, but not including, that presented in these proceedings. The situation regarding low-mass stars in the field and in clusters, high-mass stars…
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…
Theoretical and indirect observational evidences suggest that stellar initial mass function (IMF) increases with redshift. On the other hand star formation rates (SFR) may be as high as 100 $M_{\odot}$ yr$^{-1}$ in star burst galaxies.…
We attempt to evaluate whether the integrated galactic IMF (IGIMF) is expected to be steeper than the IMF within individual clusters through direct evaluation of whether there is a systematic dependence of maximum stellar mass on cluster…
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…
The Stellar Initial Mass Function (IMF) characterizes the mass distribution of newly formed stars in various cosmic environments, serving as a fundamental assumption in astrophysical research. Recent findings challenge the prevalent notion…
Recent work has suggested that the stellar initial mass function (IMF) is not universal, but rather is correlated with galaxy stellar mass, stellar velocity dispersion, or morphological type. In this paper, we investigate variations of the…
We present new Keck spectroscopy of early-type galaxies in three galaxy clusters at z~0.5. We focus on the fundamental plane (FP) relation, and combine the kinematics with structural parameters determined from HST images. The galaxies obey…