Related papers: Accretion-Induced Collimated Fast Wind Model for E…
The Galactic microquasar SS433 occasionally exhibits a major flare when the intensity of its emission increases significantly and rapidly. We present an analysis of high-resolution, almost-nightly optical spectra obtained before, during and…
The inner parsec of our Galaxy contains tens of Wolf-Rayet stars whose powerful outflows are constantly interacting while filling the region with hot, diffuse plasma. Theoretical models have shown that, in some cases, the collision of…
A large fraction of stars in binary systems are expected to undergo mass and angular momentum exchange at some point in their evolution, which can drastically alter the chemical and dynamical properties and fates of the systems. Interaction…
Recurring outbursts associated with matter flowing onto compact stellar remnants (black-holes, neutron stars, white dwarfs) in close binary systems, provide strong test beds for constraining the poorly understood accretion process. The…
Several studies suggest that the emission properties of a star can be affected by its interaction with a nearby planet. However, the actual observability of these effects remains a subject of debate. An example is the HD189733A system,…
Context: The colliding-wind binary Eta Car exhibits soft X-ray thermal emission that varies strongly around periastron, and non-thermal emission seen in hard X-rays and gamma-rays. Aims: To definitively identify Eta Car as the source of the…
Collimated fast winds (CFWs) have been proposed to operate during the post-AGB evolutionary phase (and even earlier during the late AGB phase), responsible for the shaping of pre-planetary nebulae (PPNs) and young planetary nebulae (PNs).…
I develop a detailed empirical model for the chromosphere and wind of 31 Cyg based on a previously published analysis of IUE spectra from the 1993 eclipse and on the thermodynamics of how the wind must be driven. I then use this model to…
Stellar winds are a major source of uncertainty in understanding the life and deaths of massive stars. Across studies in the field, prescriptions for stellar winds differ substantially in both their physical assumptions and implementation,…
In this paper we present observations of eta Carinae in the 1.3 mm and 7 mm radio continuum, during the 2003.5 low excitation phase. The expected minimum in the light curves was confirmed at both wavelengths and was probably due to a…
Eta Car is one of the most intriguing luminous blue variables in the Galaxy. Observations and models at different wavelengths suggest a central binary with a 5.54 yr period residing in its core. 2D and 3D radiative transfer and hydrodynamic…
The luminous blue variable Eta Carinae is surrounded by a complex and highly structured nebula of ejected material. The best-studied and axisymmetric components of this outflow consist of bipolar lobes (the ``homunculus'') and an equatorial…
We present SPH simulations of protoclusters including the effects of winds from massive stars. Using a particle-injection method, we investigate the effect of structure close to the wind sources and the short-timescale influence of winds on…
Eta Carinae (Eta Car) is one of the most massive binary stars in the Milky Way. It became the second-brightest star in the sky during its mid-19th century "Great Eruption," but then faded from view (with only naked-eye estimates of…
The massive evolved Wolf-Rayet stars sometimes occur in colliding-wind binary systems in which dust plumes are formed as a result of the collision of stellar winds. These structures are known to encode the parameters of the binary orbit and…
How T Tauri stars remain slowly rotating while still accreting material is a long-standing puzzle. Current models suggest that these stars may lose angular momentum through magnetospheric ejections of disk material (MEs) and…
We investigate the generation of intrinsically asymmetric or {\it one-sided} outflows or jets from disk accretion onto rotating stars with complex magnetic fields using axisymmetric (2.5D) magnetohydrodynamic simulations. The intrinsic…
Stellar winds may be important for angular momentum transport from accreting T Tauri stars, but the nature of these winds is still not well-constrained. We present some simulation results for hypothetical, hot (~1e6 K) coronal winds from T…
A fraction of the radiation produced by an accretion disk may be Thomson scattered by a wind flowing away from the disk. Employing a simple plane-parallel model of the wind, we calculate the polarization of the scattered radiation and find…
If massive stars form by disk accretion, then bipolar outflows should be generated as in the case of low-mass star formation. High accretion rates lead to high outflow rates and make the wind density very large near the protostar. We…