Three-dimensional hydrodynamical simulations of colliding stars . III - Collisions and tidal captures of unequal-mass main-sequence stars

1992 ◽  
Vol 389 ◽  
pp. 546 ◽  
Author(s):  
W. Benz ◽  
J. G. Hills
Keyword(s):  
Main Sequence ◽  
Three Dimensional ◽  
Main Sequence Stars ◽  
Unequal Mass ◽  
Hydrodynamical Simulations

scholarly journals Disc formation and jet inclination effects in common envelopes

2020 ◽  
Vol 497 (2) ◽  
pp. 2057-2065 ◽  
Author(s):  
Diego López-Cámara ◽  
Enrique Moreno Méndez ◽  
Fabio De Colle
Keyword(s):  
Main Sequence ◽  
Three Dimensional ◽  
Compact Object ◽  
Main Sequence Stars ◽  
Common Envelope ◽  
Ejection Process ◽  
The Common ◽  
Red Giant ◽  
Hydrodynamical Simulations ◽  
Disc Formation

ABSTRACT The evolution and physics of the common envelope (CE) phase are still not well understood. Jets launched from a compact object during this stage may define the evolutionary outcome of the binary system. We focus on the case in which jets are launched from a neutron star (NS) engulfed in the outer layers of a red giant (RG). We run a set of three-dimensional hydrodynamical simulations of jets with different luminosities and inclinations. The luminosity of the jet is self-regulated by the mass accretion rate and an efficiency η. Depending on the value of η the jet can break out of the previously formed bulge (‘successful jet’) and aligns against the incoming wind, in turn, it will realign in favour of the direction of the wind. The jet varies in size and orientation and may present quiescent and active epochs. The inclination of the jet and the Coriolis and centrifugal forces, only slightly affect the global evolution. As the accretion is hypercritical, and the specific angular momentum is above the critical value for the formation of a disc, we infer the formation of a disc and launching of jets. The discs’ mass and size would be ∼10−2 M⊙ and ≳1010 cm, and it may have rings with different rotation directions. In order to have a successful jet from a white dwarf, the ejection process needs to be very efficient (η ∼ 0.5). For main-sequence stars, there is not enough energy reservoir to launch a successful jet.

scholarly journals Building Blue Stragglers with Stellar Collisions

2007 ◽  
Vol 3 (S246) ◽  
pp. 363-364
Author(s):  
Evert Glebbeek ◽  
Onno R. Pols
Keyword(s):  
Main Sequence ◽  
Main Sequence Star ◽  
Main Sequence Stars ◽  
Blue Stragglers ◽  
Stellar Collisions ◽  
Hydrodynamical Simulations

AbstractThe evolution of stellar collision products in cluster simulations has usually been modelled using simplified prescriptions. Such prescriptions either replace the collision product with an (evolved) main sequence star, or assume that the collision product was completely mixed during the collision.It is known from hydrodynamical simulations of stellar collisions that collision products are not completely mixed, however. We have calculated the evolution of stellar collision products and find that they are brighter than normal main sequence stars of the same mass, but not as blue as models that assume that the collision product was fully mixed during the collision.

scholarly journals The interaction of core-collapse supernova ejecta with a stellar companion

2018 ◽  
Vol 14 (S346) ◽  
pp. 55-58
Author(s):  
Zheng-Wei Liu ◽  
T. M. Tauris ◽  
F. K. Röpke ◽  
T. J. Moriya ◽  
M. Kruckow ◽  
...  
Keyword(s):  
Binary Systems ◽  
Main Sequence ◽  
Three Dimensional ◽  
Core Collapse ◽  
Chemical Contamination ◽  
Binary Separation ◽  
Hydrodynamical Simulations ◽  
Many Core ◽  
The Impact

AbstractThe progenitors of many core-collapse supernovae (CCSNe) are expected to be in binary systems. By performing a series of three-dimensional hydrodynamical simulations, we investigate how CCSN explosions affect their binary companion. We find that the amount of removed stellar mass, the resulting impact velocity, and the chemical contamination of the companion that results from the impact of the SN ejecta, strongly increases with decreasing binary separation and increasing explosion energy. Also, it is foud that the impact effects of CCSN ejecta on the structure of main-sequence (MS) companions, and thus their long term post-explosion evolution, are in general not dramatic.

scholarly journals Long-term evolution of surviving companion stars of Type Iax supernovae

2020 ◽  
Vol 500 (1) ◽  
pp. 301-309
Author(s):  
Zheng-Wei Liu ◽  
Yaotian Zeng
Keyword(s):  
Stellar Evolution ◽  
Main Sequence ◽  
Three Dimensional ◽  
Late Time ◽  
One Dimensional ◽  
Term Evolution ◽  
Post Impact ◽  
Explosion Mechanism ◽  
Hydrodynamical Simulations

ABSTRACT The nature of the progenitors and explosion mechanism of Type Iax supernovae (SNe Iax) remain a mystery. The single-degenerate (SD) systems that involve the incomplete pure deflagration explosions of near-Chandrasekhar-mass white dwarfs (WDs) have recently been proposed for producing SNe Iax in which non-degenerate companions are expected to survive from SN explosions. In this work, we concentrate on the main-sequence (MS) donor SD progenitor systems. By mapping the computed companion models from three-dimensional hydrodynamical simulations of ejecta-companion interaction into a one-dimensional stellar evolution code mesa, we investigate the long-term appearance and observational signatures of surviving MS companions of SNe Iax by tracing their post-impact evolution. Depending on different MS companion models, it is found that the shocked surviving companion stars can significantly expand and evolve to be more luminous (5–$500\, L_{\odot }$) for a time-scale of 10–104 yr. Comparing with the late-time light curve of an observed SN Iax (SN 2005hk), it is suggested that surviving MS companions of SNe Iax would expect to be visible about 1000 d after the explosion when SN itself has been faded.

Chromospheric activity as a function of age in main-sequence stars

1966 ◽  
Vol 24 ◽  
pp. 40-43
Author(s):  
O. C. Wilson ◽  
A. Skumanich
Keyword(s):  
Main Sequence ◽  
The Sun ◽  
Main Sequence Stars ◽  
Tentative Conclusion ◽  
Chromospheric Activity ◽  
General Field ◽  
Large Clusters

Evidence previously presented by one of the authors (1) suggests strongly that chromospheric activity decreases with age in main sequence stars. This tentative conclusion rests principally upon a comparison of the members of large clusters (Hyades, Praesepe, Pleiades) with non-cluster objects in the general field, including the Sun. It is at least conceivable, however, that cluster and non-cluster stars might differ in some fundamental fashion which could influence the degree of chromospheric activity, and that the observed differences in chromospheric activity would then be attributable to the circumstances of stellar origin rather than to age.

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