Related papers: Radiating the hydrogen recombination energy during…
Performing a series of hydrodynamic stellar evolutionary simulations with \textsc{Mesa} (Module for Experiments in Stellar Astrophysics), we investigate the excitation and growth of radial pulsations of massive red supergiants (RSGs) with…
We analyze a 3D hydrodynamic simulation of common envelope evolution to understand how energy is transferred between various forms and whether theory and simulation are mutually consistent given the setup. Virtually all of the envelope…
Evolved massive stars are known to undergo outflow with high mass ejections, resulting in the loss of a substantial portion of their envelopes. One proposed mechanism driving these events is the release or deposition of energy within the…
The common envelope phase of binary star evolution plays a central role in many evolutionary pathways leading to the formation of compact objects in short period systems. Using three dimensional hydrodynamical computations, we review the…
Common-envelope evolution is a stage in binary system evolution in which a giant star engulfs a companion. The standard energy formalism is an analytical framework to estimate the amount of energy transferred from the companion's shrinking…
We conduct three-dimensional hydrodynamical simulations, and show that when a secondary star launches jets while performing spiral-in motion into the envelope of a giant star, the envelope is inflated, some mass is ejected by the jets, and…
We solve the recombination equation by taking into account the induced recombinations and a physical cut off in the hydrogen spectrum. The effective recombination coefficient is parametrized as a function of temperature and free electron…
We conduct a three-dimensional hydrodynamical simulation of a common envelope evolution (CEE) where a neutron star (NS) spirals-in inside the envelope of a red supergiant (RSG) star in a predetermined orbit. We find that the jets shed pairs…
Motivated by the recent observation by NICER of a type I X-ray burst from SAX J1808.4-3658 with a distinct "pause" feature during its rise (Bult et al. 2019), we show that bursts which ignite in a helium layer underneath a hydrogen-rich…
The light curves of type-II supernovae (SNe) are believed to be highly affected by recombination of hydrogen that takes place in their envelopes. In this work, we analytically investigate the transition from a fully ionized envelope to a…
This paper continues our study of the behaviour of near infrared helium recombination lines in planetary nebula. We find that the 1.7007um 4^3D-3^3P HeI line is a good measure of the HeI recombination rate, since it varies smoothly with the…
Detached WD+MS PCEBs are perhaps the most suitable objects for testing predictions of close-compact binary-star evolution theories, in particular, CE evolution. The population of WD+MS PCEBs has been simulated by several authors in the past…
The formation of a double white dwarf binary likely involves a common envelope (CE) event between a red giant and a white dwarf (WD) during the most recent episode of Roche lobe overflow mass transfer. We study the role of recombination…
High-resolution numerical simulations including feedback and aimed at calculating the escape fraction (fesc) of hydrogen-ionizing photons often assume stellar radiation based on single-stellar population synthesis models. However, strong…
Using the one-dimensional numerical code MESA, we simulate mass accretion at very high rates onto massive main sequence stars, M=30, 60, 80 Mo, and find that these stars can accrete up to 10% of their mass without expanding much if we…
The binding energy parameter $\lambda$ plays a vital role in common envelope evolution. Though it is well known that $\lambda$ takes different values for stars with different masses and varies during stellar evolution, it has been…
We investigate the possibility of maser amplification in hydrogen recombination lines from the galaxies of first generation, at z<~30. Combining analytical and computational approaches, we show that the transitions between the hydrogen…
A binary neutron star merger has been observed in a multi-messenger detection of gravitational wave (GW) and electromagnetic (EM) radiation. Binary neutron stars that merge within a Hubble time, as well as many other compact binaries, are…
We simulate the influence of the energy that the merger process of two neutron stars (NSs) releases inside a red supergiant (RSG) star on the RSG envelope inner to the merger location. In the triple star common envelope evolution (CEE) that…
Early observations of supernovae (SNe) indicate that enhanced mass loss and pre-SN outbursts may occur in progenitors of many types of SNe. We investigate the role of energy transport via waves driven by vigorous convection during…