Related papers: The Initial Mass Function toward the low-mass end …
We investigate the most plausible stellar Initial Mass Function (IMF) and the main origin of the tilt of the Fundamental Plane (FP) for old, massive early-type galaxies. We consider a sample of 13 bright galaxies of the Coma cluster and…
The distribution of core radii of rich clusters in the Large Magellanic Cloud (LMC) systematically increases in both upper limit and spread with increasing cluster age. Cluster-to-cluster variations in the stellar initial mass function…
Studies of the resolved stellar populations of young massive clusters have shown that the slope of the initial mass function appears to be the same everywhere, with no dependence on stellar density or metallicity. At the same time, studies…
Recent papers have found that the inferred slope of the high-mass ($>1.5$ M$_\odot$) IMF for field stars in the solar vicinity has a larger value ($\sim 1.7-2.1$) than the slopes ($\sim 1.2-1.7$; Salpeter= 1.35) inferred from numerous…
It is now well-established that the stellar initial mass function (IMF) can be determined from the absorption line spectra of old stellar systems, and this has been used to measure the IMF and its variation across the early-type galaxy…
We present a luminosity function (LF) for lower main sequence stars in the Galactic bulge near (l,b)=(0,-6) to J=24, corresponding to M_J~9.3. This LF is derived from HST + NICMOS observations with the F110W and F160W filters. The main…
We present observational evidence of the correlation between the high-mass slope of the stellar initial mass function (IMF) in young star clusters and their stellar surface density, $\sigma_{*}$. When the high-mass end of the IMF is…
Among the most central open questions regarding the initial mass function (IMF) of stars is the impact of environment on the shape of the core mass function (CMF) and thus potentially on the IMF. The ALMA-IMF Large Program aims to…
Using deep HST/ACS observations, we demonstrate that the sub-solar stellar initial mass function (IMF) of 6 ultra-faint dwarf Milky Way Satellites (UFDs) is more bottom light than the IMF of the Milky Way disk. Our data have a lower mass…
The supermassive black hole at the center of the Milky Way plays host to a massive, young cluster that may have formed in one of the most inhospitable environments in the Galaxy. We present new measurements of the global properties of this…
Johnson {\it BV} CCD observations have been made of the young Large Magellanic Cloud cluster NGC~2214 and a nearby field using the Anglo-Australian Telescope. It has been suggested in the literature that this elliptical cluster is actually…
Observed variations in the slope of the initial stellar mass function are shown to be consistent with a model in which the protostellar gas is randomly sampled from hierarchical clouds at a rate proportional to the square root of the local…
We present new evidence for a variable stellar initial mass function (IMF) in massive early-type galaxies, using high-resolution, near-infrared spectroscopy from the Folded-port InfraRed Echellette spectrograph (FIRE) on the Magellan Baade…
The spectral absorption lines in early-type galaxies contain a wealth of information regarding the detailed abundance pattern, star formation history, and stellar initial mass function (IMF) of the underlying stellar population. Using our…
Any predictive theory of star formation must explain observed variations (or lack thereof) in the initial mass function. Recent work suggests that we might expect quantitative variations in the IMF as a function of metallicity (Larson 2005)…
We present a new approach in the study of the Initial Mass function (IMF) in external galaxies based on quasar microlensing observations. We use measurements of quasar microlensing magnifications in 24 lensed quasars to estimate the average…
(Abridged) Accurate luminosity functions (LF) for a dozen globular clusters have now been measured at or just beyond their half-light radius using HST. They span almost the entire cluster main sequence below ~ 0.75 Msolar. All these…
The observed masses of the most massive stars do not surpass about 150Msun. This may either be a fundamental upper mass limit which is defined by the physics of massive stars and/or their formation, or it may simply reflect the increasing…
Many results in modern astrophysics rest on the notion that the Initial Mass Function (IMF) is universal. Our observations of HI selected galaxies in the light of H-alpha and the far-ultraviolet (FUV) challenge this notion. The flux ratio…
We investigate the origin of a bottom-heavy stellar initial mass function (IMF) recently observed in elliptical galaxies by using chemical evolution models with a non-universal IMF. We adopt the Kroupa IMF with the three slopes (alpha_1,…