scholarly journals Numerical Study of Colliding Winds in Massive Stars

Galaxies ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Amit Kashi ◽  
Amir Michaelis
Keyword(s):  
Accretion Rate ◽  
Numerical Study ◽  
Mass Loss Rate ◽  
Stellar Winds ◽  
Large Set ◽  
Momentum Ratio ◽  
Mass Accretion Rate ◽  
Wind Structure ◽  
Colliding Winds ◽  
Orbital Solution

We run a numerical experiment ejecting stellar winds in a very massive binary system measuring the properties of the resulting colliding wind structure and accreted mass onto the companion under different conditions. Colliding massive binaries interact and create a colliding wind structure with a shape that depends on the momentum ratio, orbital motion, distance between the stars, and other factors. We run simulations of a static LBV-WR binary and in each simulation abruptly varying the mass loss rate of the LBV from the fiducial value. The modified wind front propagates and interacts with the previous colliding wind structure, and modifies its shape. We calculate the emitted X-ray from the interaction and investigate the proprieties of the new shape. We derive the mass accretion rate onto the secondary, and find that it depends on the momentum ratio of the winds. We then add orbital velocity that reduces the mass accretion rate, a similar behaviour as the analytical estimates based on modified Bondi–Hoyle–Lyttleton. Creating a large set of simulations like those presented here can allow constraining parameters for specific colliding wind binaries and derive their stellar parameters and orbital solution.

scholarly journals The relativistic mass accretion rate for accretion disk in the equatorial of rapidly rotating neutron stars

2021 ◽  
Vol 1869 (1) ◽  
pp. 012156
Author(s):  
A Yasrina ◽  
N Widianingrum ◽  
N S Risdianto ◽  
D Andra ◽  
N A Pramono ◽  
...  
Keyword(s):  
Neutron Stars ◽  
Accretion Disk ◽  
Accretion Rate ◽  
Mass Accretion Rate ◽  
Relativistic Mass

scholarly journals Searching for a link between the magnetic nature and other observed properties of Herbig Ae/Be stars

2008 ◽  
Vol 4 (S259) ◽  
pp. 395-396 ◽  
Author(s):  
Swetlana Hubrig ◽  
C. Grady ◽  
M. Schöller ◽  
O. Schütz ◽  
B. Stelzer ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Survey ◽  
Accretion Rate ◽  
Be Stars ◽  
General Correlation ◽  
X Ray ◽  
Mass Accretion Rate ◽  
Debris Disk ◽  
Magnetic Nature

AbstractWe present the results of a new magnetic field survey of Herbig Ae/Be and A debris disk stars. They are used to determine whether magnetic field properties in these stars are correlated with the mass-accretion rate, disk inclinations, companion(s), Silicates, PAHs, or show a more general correlation with age and X-ray emission as expected for the decay of a remnant dynamo.

scholarly journals Rapid Mass Accretion in the Symbiotic Star AG Dra

1987 ◽  
Vol 93 ◽  
pp. 759-762
Author(s):  
T. Iijima
Keyword(s):  
White Dwarf ◽  
Accretion Rate ◽  
Symbiotic Star ◽  
Mass Accretion Rate ◽  
Accretion Process ◽  
Rapid Mass

AbstractThe mass accretion process onto the hot component of AG Dra and its explosive phenomena are discussed. The hot component seems to be a massive white dwarf (M > 1 M⊙). The mass accretion rate is estimated to be about 10−7M⊙/year. Many properties of the explosive phenomena agree with those of mild hydrogen flashes expected from this rapid mass accretion.

scholarly journals Optical and X-ray observations of stellar winds in Wolf-Rayet binaries

1995 ◽  
Vol 163 ◽  
pp. 262-270
Author(s):  
A. M. Cherepashchuk
Keyword(s):  
Chemical Composition ◽  
Core Temperature ◽  
Stellar Winds ◽  
Radial Expansion ◽  
Core Radius ◽  
X Ray ◽  
The Core ◽  
Basic Conclusion ◽  
Helium Stars ◽  
Colliding Winds

New spectrophotometric, photometric and polarimetric observations of V444 Cygni confirm the basic conclusion that the WN5 star has a small core radius (rc < 4 R⊙) and a high core temperature (Tc > 60 000 K), which are characteristic of massive helium stars. Values of rc < 3 — 6 R⊙ and Tc > 70 000 — 90 000 K for the core of the WN7 star in the Cygnus X-3 system agree well with this conclusion. A clumping structure of WR winds is suggested. X-ray observations of colliding winds in WR+O binaries suggest radial expansion and anomalous chemical composition of WR winds.

Formation of the SMC WO+O binary AB8

2018 ◽  
Vol 14 (S346) ◽  
pp. 78-82
Author(s):  
Chen Wang ◽  
Norbert Langer ◽  
Götz Gräfener ◽  
Pablo Marchant
Keyword(s):  
Binary Systems ◽  
Mass Loss Rate ◽  
Vital Role ◽  
Least Square ◽  
High Mass ◽  
Stellar Winds ◽  
High Mass Loss ◽  
Low Metallicity ◽  
Binary Evolution ◽  
Oxygen Ratio

AbstractWolf-Rayet (WR) stars are stripped stellar cores that form through strong stellar wind or binary mass transfer. It is proposed that binary evolution plays a vital role in the formation of WR stars in low metallicity environments due to the metallicity dependance of stellar winds. However observations indicate a similar binary fraction of WR stars in the Small Magellanic Cloud (SMC) compared to the Milky Way. There are twelve WR stars in the SMC and five of them are members of binary systems. One of them (SMC AB8) harbors a WO type star. In this work we explore possible formation channels of this binary. We use the MESA code to compute large grids of binary evolution models, and then use least square fitting to compare our models with the observations. In order to reproduce the key properties of SMC AB8, we require efficient semiconvection to produce a sufficiently large convective core, as well as a longer He-burning lifetime. We also need a high mass loss rate during the WN stage to assist the removal of the outer envelope. In this way, we can reproduce the observed properties of AB8, except for the surface carbon to oxygen ratio, which requires further investigation.

scholarly journals H2O maser emission from the Seyfert 2 galaxy IC 2560: evidence for a super-massive black hole and a probe for mass-accretion rate

2002 ◽  
Vol 206 ◽  
pp. 400-403
Author(s):  
Yuko Ishihara ◽  
Naomasa Nakai ◽  
Naoko Iyomoto ◽  
Kazuo Makishima ◽  
Phil Diamond ◽  
...  
Keyword(s):  
Black Hole ◽  
High Velocity ◽  
Accretion Rate ◽  
Rotating Disk ◽  
Massive Black Hole ◽  
Central Mass ◽  
Maser Emission ◽  
Mass Accretion Rate ◽  
Systemic Velocity ◽  
Velocity Drift

Our observations of H2O masers have detected some high-velocity features and a secular velocity drift of the systemic features in the Seyfert 2 Galaxy IC 2560. The high-velocity features were blue- and red-shifted from the systemic velocity of 220-420 km s−1 and 210-350 km s−1, respectively. The velocity of the systemic features drifted at a secular rate of 2.62 km s−1 yr−1. Assuming the existence of a compact rotating disk as in NGC 4258, IC 2560 possesses a nuclear disk with inner and outer radii of 0.07 pc and 0.26 pc, respectively, and a confined mass of 2.8 × 106M⊙ at the center, making the central density > 2.1 × 109M⊙ pc−3. Such a dense object cannot be a cluster of stars, and this strongly suggests that the central mass is a super-massive black hole. Since the 2-10 keV luminosity of IC 2560 is 1 × 1041 erg s−1, the mass accretion rate of the suggested black hole must be 2 × 10−5M⊙ yr−1.

scholarly journals Influence of the Stellar Winds on the Evolution of the Planetary Nebula Nuclei

1993 ◽  
Vol 155 ◽  
pp. 483-483
Author(s):  
S.K. Górny
Keyword(s):  
Mass Loss ◽  
Planetary Nebula ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Stellar Winds ◽  
Hydrogen Burning ◽  
Wind Theory ◽  
Homogeneous Models ◽  
Image Position ◽  
Zero Points

A grid of homogeneous models of evolution of hydrogen burning planetary nebulae nuclei, assuming different stellar winds and the zero points for the post-AGB evolution, have been constructed from original Schönberners tracks. Following a simplified line-driven wind theory the mass loss rate has been adopted to be

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