Related papers: Very Large Array Observations of Winds from Massiv…

We discuss the determination of fundamental parameters of `normal' hot, massive OB-type stars, namely temperatures, luminosities, masses, gravities and surface abundances. We also present methods used to derive properties of stellar winds…

Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM observations,…

Massive stars lose a large fraction of their mass to radiation-driven winds throughout their entire life. These outflows impact both the life and death of these stars and their surroundings. Theoretical mass-loss rates of hot, massive stars…

Spectroscopic observations have shown for decades that the Wolf-Rayet (WR) phenomenon is ubiquitous among stars with different initial masses. Although much effort to understand the winds from massive WR stars has been presented in the…

In the regime of hot stars, winds were not seen as a common thing until the era of UV astronomy. Since we have access to the UV wavelength range, it has become clear that winds are not an exotic phenomenon limited to some special objects,…

We review basic physics of line-driven stellar winds of OB stars. We discuss elementary processes due to which stellar winds are accelerated on a microscopic level. We show how these microscopic processes may enable the outflow and how they…

This thesis discusses the influence of magnetic fields on the instability of line-driven winds in O-stars and Wolf-Rayet stars. This combination is an important concept to understand the strong, observed winds from Wolf-Rayet stars. In the…

Recent studies of high-redshift galaxies using JWST, such as GN-z11 revealed highly elevated levels of nitrogen (N). This phenomenon extends to gravitationally-lensed galaxies like the Sunburst Arc at z = 2.37, as well as to globular…

Aims: Non-thermal radio emission associated with massive stars is believed to arise from a wind-wind collision in a binary system. However, the evidence of binarity is still lacking in some cases, notably Cyg OB2 #9 Methods: For several…

Detailed knowledge about stellar winds and evolution at different metallicities is crucial for understanding stellar populations and feedback in the Local Group of galaxies and beyond. Despite efforts in the literature, we still lack a…

This paper reports a blind search for magnetospheric emissions from planets around nearby stars. Young stars are likely to have much stronger stellar winds than the Sun, and because planetary magnetospheric emissions are powered by stellar…

Massive stars and their stellar winds are important for a number of feedback processes. The mass lost in the stellar wind can help determine the end-point of the star as a NS or a BH. However, the impact of mass-loss on the post-Main…

Colliding winds of massive stars in binary systems are considered as candidate sites of high-energy non-thermal photon emission. They are already among the suggested counterparts for a few individual unidentified EGRET sources, but may…

We report on the analysis of the Chandra-ACIS data of O, B and WR stars in the young association Cyg OB2. X-ray spectra of 49 O-stars, 54 B-stars and 3 WR-stars are analyzed and for the brighter sources, the epoch dependence of the X-ray…

First attempts are made to derive astrophysical implications of the collision of clumped stellar winds from order of magnitude estimates and preliminary numerical simulations. Compared to colliding smooth winds, we find that the most…

Hot, massive (OB) stars experience strong line-driven stellar winds and mass loss. As the majority of efficient driving lines are metallic, the amount of wind driving and mass loss is dependent on the stellar metallicity Z. In addition,…

Gamma-ray observations of young star clusters have recently provided evidence for particle acceleration occurring at stellar wind termination shocks, fueled by the mechanical energy of stellar winds from massive stars. In this work, we…

Extremely high velocity (EHV) wings, with full widths of 72 to 140 km/s, are seen on the CO J=3-2 lines toward W3 IRS 5, GL 490, NGC 2071, W28 A2, GL 2591, S140, and Cepheus A. The results of our survey suggest that EHV wings are common…

The massive, luminous Population I Wolf-Rayet stars can be considered as stars with the highest known sustained mass loss rates. Around 10% of WR stars may form carbon-rich dust in their dense and inhomogeneous winds. Though we are yet 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,…