Related papers: FASTAR -- II. Semi-resolved evolutionary stellar p…
Growing evidence suggests that the stellar initial mass function (IMF) varies systematically across galaxies, deviating from the canonical Milky Way form. Such variations would modify the integrated nucleosynthetic yields, and hence the…
The apparent age and mass of a stellar cluster can be strongly affected by stochastic sampling of the stellar initial mass function, when inferred from the integrated color of low mass clusters (less than ~10^4 solar masses). We use…
In this work, we investigate the reliability of spectral synthesis methods in the estimation of the mean stellar age and metallicity, addressing the question of which signal-to-noise ratios (S/N) are needed to determine these quantities. To…
We present a new library of semi-empirical stellar population models that are based on the empirical MILES and semi-empirical sMILES stellar libraries. The models span a large range of age and metallicity, in addition to an [$\alpha$/Fe]…
The strength of gravity-sensitive absorption lines in the integrated light of old stellar populations is one of the few direct probes of the stellar initial mass function (IMF) outside of the Milky Way. Owing to the advent of fully depleted…
We present robust statistical estimates of the accuracy of early-type galaxy stellar masses derived from spectral energy distribution (SED) fitting as functions of various empirical and theoretical assumptions. Using large samples…
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…
We determine an absolute calibration of stellar mass-to-light ratios for the densest \simeq 3% of early-type galaxies in the local universe (redshift z\simeq 0.08) from SDSS DR7. This sample of \sim 4000 galaxies has, assuming a Chabrier…
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…
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…
Stellar population studies of massive early-type galaxies (ETGs) suggest that the stellar initial mass function may not be universal. In particular, the centres of ETGs seem to contain an excess of low-mass dwarf stars compared to our own…
Interpreting galactic luminosity requires assumptions about the galaxy-wide initial mass function (gwIMF), often assumed invariant in most stellar population synthesis (SPS) models. If stars form in clusters with metallicity- and…
We present models for the initial mass function (IMF) for stars forming within molecular clouds. These models use the idea that stars determine their own masses through the action of powerful stellar outflows. This concept allows us to…
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…
Low metallicity stellar populations are very abundant in the Universe, either as the remnants of the past history of the Milky Way or similar spiral galaxies, or the young low metallicity stellar populations that are being observed in the…
Star Formation Rate (SFR) inferences are based in the so-called constant SFR approximation, where synthesis models are require to provide a calibration; we aims to study the key points of such approximation to produce accurate SFR…
Studies of the broad emission-line regions (BLRs) in quasars have revealed solar or higher enrichment levels up to the highest redshifts. In combination with the presence of large amounts of dust in QSOs at $z$ about 6, this implies that…
Our unified chemical and spectrophotometric evolution code allows to simultaneously study the ISM abundances of a series of elements and the spectral properties of the stellar population in our model galaxies. We use stellar evolutionary…
We have analyzed HST/NICMOS2 F110W, F160W, F165M, and F207M band images covering the central 1'x1' of the cluster associated with Mon R2 in order to constrain the Initial Mass Function (IMF) down to 20 Mjup. The flux ratio between the F165M…
The non-detection of zero-metallicity stars in ultra-faint dwarf galaxies (UFDs) can be used to constrain the Initial Mass Function (IMF) of the first (PopIII) stars by means of a statistical comparison between available data and…