Related papers: Binary Stars Can Provide the "Missing Photons" Nee…
The dark ages of the Universe end with the formation of the first generation of stars residing in primeval galaxies. These objects were the first to produce ultraviolet ionizing photons in a period when the cosmic gas changed from a neutral…
Newly formed stars have a profound impact on their environment by depositing energy and momentum into the surrounding gas. However, only a fraction of the stellar feedback is retained in the cloud and observational constraints are needed to…
Nearby companions alter the evolution of massive stars in binary systems. Using a sample of Galactic massive stars in nearby young clusters, we simultaneously measure all intrinsic binary characteristics relevant to quantify the frequency…
We present a new analysis of the ionizing emissivity ($\dot{N}_{\rm{ion}}$, s$^{-1}$ Mpc$^{-3}$) for galaxies during the epoch of reionization and their potential for completing and maintaining reionization. We use extensive SED modelling…
We present a combined analysis of rest-frame far-UV (1000-2000 A) and rest-frame optical (3600-7000 A) composite spectra formed from very deep observations of a sample of 30 star-forming galaxies with z=2.4+/-0.1, selected to be…
The Binary Population and Spectral Synthesis (BPASS) suite of binary stellar evolution models and synthetic stellar populations provides a framework for the physically motivated analysis of both the integrated light from distant stellar…
A large number of high-redshift galaxies have been discovered via their narrow-band Lya line or broad-band continuum colors in recent years. The nature of the escaping process of photons from these early galaxies is crucial to understanding…
We calculate the reionization history for different models of the stellar population and explore the effects of primordial magnetic fields, dark matter decay and dark matter annihilation on reionization. We find that stellar populations…
Extrasolar planets and belts of debris orbiting post-main-sequence single stars may become unbound as the evolving star loses mass. In multiple star systems, the presence or co-evolution of the additional stars can significantly complicate…
We present a semi-analytic model for the thermal and ionization history of the universe at 1000 >~ z >~ 3. This model incorporates much of the essential physics included in full-scale hydrodynamical simulations, such as (1) gravitational…
Binary stars are thought to be a controlling factor in globular cluster evolution, since they can heat the environmental stars by converting their binding energy to kinetic energy during dynamical interactions. Through such interaction, the…
Massive stars at redshifts z > 6 are predicted to have played a pivotal role in cosmological reionization as luminous sources of ultra-violet (UV) photons. However, the remnants of these massive stars could be equally important as X-ray…
The UV escape fraction from high-redshift galaxies plays a key role in models of cosmic reionisation. Because it is currently not possible to deduce the escape fractions during the epoch of reionisation from observations, we have to rely on…
The fraction of ionizing photons escaping from high-redshift star-forming galaxies remains a key obstacle in evaluating whether galaxies were the primary agents of cosmic reionization. We previously proposed using the covering fraction of…
The excursion set reionization framework is widely used, due to its speed and accuracy in reproducing the 3D topology of reionization. However, it is known that it does not conserve photon number. Here, we introduce an efficient, on-the-fly…
Recent observations of galaxies at $z \gtrsim 7$, along with the low value of the electron scattering optical depth measured by the Planck mission, make galaxies plausible as dominant sources of ionizing photons during the epoch of…
Recent data indicates that the cosmic UV emissivity decreased with decreasing redshift z near the end of reionization. Lacking evidence for very massive early stars, this could signal a decline with time in the mass-averaged escape fraction…
In this work we investigate the properties of the sources that reionized the intergalactic medium (IGM) in the high-redshift Universe. Using a semi-analytical model aimed at reproducing galaxies and black holes in the first 1.5 Gyr of the…
Eclipsing binary stars provide highly accurate measurements of the fundamental physical properties of stars. They therefore serve as stringent tests of the predictions of evolutionary models upon which most stellar age determinations are…
Be stars are rapidly rotating B type stars. The origin of their rapid rotation is not certain, but binary interaction remains to be a possibility. In this work we investigate the formation of Be stars resulting from mass transfer in…