Related papers: Finding He II: Testing Novel Models of Binary Popu…
Many aspects of the evolution of stars, and in particular the evolution of binary stars, remain beyond our ability to model them in detail. Instead, we rely on observations to guide our often phenomenological models and pin down uncertain…
Early observations with JWST indicate an over-abundance of bright galaxies at redshifts $z \gtrsim 10$ relative to Hubble-calibrated model predictions. More puzzling still is the apparent lack of evolution in the abundance of such objects…
Stars are mostly found in binary and multiple systems, as at least 50% of all solar-like stars have companions - a fraction that goes up to 100% for the most massive stars. Moreover, a large fraction of them will interact in some way or…
We performed populations synthesis calculations of single stars and binaries and show that binary evolution is extremely important for Galactic astronomy. We review several binary evolution models and conclude that they give quite different…
Binary stars are as common as single stars. Binary stars are of immense importance to astrophysicists because that they allow us to determine the masses of the stars independent of their distances. They are the cornerstone of the…
Uncertainties in stellar population models, both in terms of stellar evolution and stellar spectra, translate into uncertainties in our interpretation of stellar populations in galaxies, since stars are the source of most of the light we…
The binary fraction of a stellar population can have pronounced effects on its properties, and in particular the number counts of different massive star types, and the relative subtype rates of the supernovae which end their lives. Here we…
The modelling of massive star evolution is a complex task, and is very sensitive to the way physical processes (such as convection, rotation, mass loss, etc.) are included in stellar evolution code. Moreover, the very high observed fraction…
Our uncertainties about binary star systems (and triples and so on) limit our capabilities in literally every single one of the Thematic Areas identified for Astro2020. We need to understand the population statistics of stellar multiplicity…
We utilize medium-resolution JWST/NIRSpec observations of 164 galaxies at $z=2.0-9.3$ from the Cosmic Evolution Early Release Science (CEERS) survey to investigate the evolution of the excitation and ionization properties of galaxies at…
The physical properties of galaxies are encoded within their spectral energy distribution and require comparison with models to be extracted. These models must contain a synthetic stellar population and, where infrared data is to be used,…
Stellar fundamental properties (masses, radii, effective temperatures) can be extracted from observations of eclipsing binary systems with remarkable precision, often better than 2%. Such precise measurements afford us the opportunity to…
This review aims to give an overview of the contribution of the Hubble Space Telescope to our understanding of the detailed properties of Local Group dwarf galaxies and their older stellar populations. The exquisite stable high spatial…
Red giants are increasingly used as stellar population tracers due to their well-understood evolution and the availability of asteroseismic observables. However, stellar binarity can alter observable properties and introduce strong biases.…
Pulsations and binarity are both common features of massive stars. The study of pulsating massive stars in eclipsing binary systems hold great potential for constraining stellar structure and evolution theory. However, prior to the all-sky…
The luminosity and spectral energy distribution (SED) of high-$z$ galaxies are sensitive to the stellar population synthesis (SPS) models. In this paper, we study the effects of different SPS models on the measurements of high-$z$ galaxies…
We study the orbital evolution of wide binary stars in the solar neighborhood due to gravitational perturbations from passing stars. We include the effects of the Galactic tidal field and continue to follow the stars after they become…
The ionizing photon production efficiency, $\xi_{ion}$, is a critical parameter that provides a number of physical constraints to the nature of the early Universe, including the contribution of galaxies to the timely completion of the…
Using cosmological simulations to make useful, scientifically relevant emission line predictions is a relatively new and rapidly evolving field. However, nebular emission lines have been particularly challenging to model because they are…
Stellar populations carry information about the formation of galaxies and their evolution up to the present epoch. A wealth of observational data are available nowadays, which are analysed with stellar population models in order to obtain…