scholarly journals How galaxies form: Mass assembly from chemical abundances in the era of large surveys

2009 ◽  
Vol 5 (S265) ◽  
pp. 461-469
Author(s):  
Rosemary F.G. Wyse
Keyword(s):  
Mass Transfer ◽  
Large Scale ◽  
Binary Systems ◽  
Milky Way ◽  
Dynamical Evolution ◽  
Close Binary ◽  
Chemical Abundances ◽  
Milky Way Galaxy ◽  
Deep Imaging ◽  
Mass Assembly

AbstractThe chemical abundances in the atmosphere of a star provide unique information about the gas from which that star formed, and, modulo processes that are not important for the vast majority of stars, such as mass transfer in close binary systems, are conserved through a star's life. Correlations between chemistry and kinematics have been used for decades to trace dynamical evolution of the Milky Way Galaxy. I discuss how it should be possible to refine and extend such analyses, provided planned large-scale deep imaging surveys have matched spectroscopic surveys.

scholarly journals Stellar multiplicity in the Milky Way Galaxy

2017 ◽  
Vol 13 (S334) ◽  
pp. 366-367
Author(s):  
E. Stonkutė ◽  
R. P. Church ◽  
S. Feltzing ◽  
J. A. Johnson
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Milky Way ◽  
Galactic Disc ◽  
Chemical Abundances ◽  
Milky Way Galaxy ◽  
The Galaxy ◽  
Tentative Evidence ◽  
Evolution Algorithm ◽  
Binary Evolution

AbstractWe present our models of the effect of binaries on high-resolution spectroscopic surveys. We want to determine how many binary stars will be observed, whether unresolved binaries will contaminate measurements of chemical abundances, and how we can use spectroscopic surveys to better constrain the population of binary stars in the Galaxy. Using a rapid binary-evolution algorithm that enables modelling of the most complex binary systems we generate a series of large binary populations in the Galactic disc and evaluate the results. As a first application we use our model to study the binary fraction in APOGEE giants. We find tentative evidence for a change in binary fraction with metallicity.

scholarly journals Evolutionary Aspects of Circumstellar Matter in Binary Systems

1973 ◽  
Vol 51 ◽  
pp. 216-259 ◽  
Author(s):  
Miroslav Plavec
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Binary Stars ◽  
Large Scale ◽  
Binary Systems ◽  
Main Sequence ◽  
Circumstellar Matter ◽  
Close Binary ◽  
X Ray ◽  
Contact Stage

Several groups of close binary stars are considered in an attempt to explain their present state as a consequence of a large-scale mass transfer or mass loss in the past: Algol-like semidetached binaries, some shell stars (AX Mon), some binary X-ray sources (Cen X-3, Her X-1), the recurrent nova T CrB, helium-rich binaries v Sgr and KS Per, and the symbiotic variables.Algol-like binaries like U Sge cannot be products of a conservative case A of mass transfer; rather, mass loss from system and/or a temporary contact stage must be invoked. Nova T CrB as well as the symbiotic variables probably contain a mass-losing giant and a helium star, which again may be a product of a previous mass transfer of type B. Similarly, some of the X-ray sources may actually be binaries undergoing a second process of mass transfer. The systems v Sgr and KS Per may contain helium stars expanding to the right of the helium main sequence, while the other component may be a rather inactive main-sequence star. Some shell stars may be products of mass transfer. Mass loss from convective envelopes is also discussed.Loss of mass and of angular momentum from many binary systems must be anticipated. Behavior of the mass-accreting stars may often be decisive for the appearance and evolution of the system.

scholarly journals The early gaseous and stellar mass assembly of Milky Way-type galaxy halos

2015 ◽  
Vol 11 (S317) ◽  
pp. 235-240
Author(s):  
Gerhard Hensler ◽  
Mykola Petrov
Keyword(s):  
Galaxy Formation ◽  
Large Scale ◽  
Milky Way ◽  
Evolutionary Model ◽  
Satellite System ◽  
Chemical Abundances ◽  
Cosmological Context ◽  
Dynamical Simulations ◽  
Satellite Galaxies ◽  
Mass Assembly

AbstractHow the Milky Way has accumulated its mass over the Hubble time, whether significant amounts of gas and stars were accreted from satellite galaxies, or whether the Milky Way has experienced an initial gas assembly and then evolved more-or-less in isolation is one of the burning questions in modern astronomy, because it has consequences for our understanding of galaxy formation in the cosmological context. Here we present the evolutionary model of a Milky Way-type satellite system zoomed into a cosmological large-scale simulation. Embedded into Dark Matter halos and allowing for baryonic processes these chemo-dynamical simulations aim at studying the gas and stellar loss from the satellites to feed the Milky Way halo and the stellar chemical abundances in the halo and the satellite galaxies.

scholarly journals Identifying the formation mechanism of redback pulsars

2020 ◽  
Vol 493 (2) ◽  
pp. 2171-2177 ◽  
Author(s):  
M A De Vito ◽  
O G Benvenuto ◽  
J E Horvath
Keyword(s):  
Mass Transfer ◽  
Neutron Star ◽  
Formation Mechanism ◽  
Binary Systems ◽  
Close Binary ◽  
Formation Mechanisms ◽  
Orbital Periods ◽  
The Moment ◽  
Strong Evaporation ◽  
Theoretical Results

ABSTRACT We analyse the evolution of close binary systems containing a neutron star that lead to the formation of redback pulsars. Recently, there has been some debate on the origin of such systems and the formation mechanism of redbacks may still be considered as an open problem. We show that the operation of a strong evaporation mechanism, starting from the moment when the donor star becomes fully convective (or alternatively since the formation of the neutron star by accretion-induced collapse), produces systems with donor masses and orbital periods in the range corresponding to redbacks with donors appreciably smaller than their Roche lobes, i.e. they have low filling factors (lower than 0.75). Models of redback pulsars can be constructed assuming the occurrence of irradiation feedback. They have been shown to undergo cyclic mass transfer during the epoch at which they attain donor masses and orbital periods corresponding to redbacks, and stay in quasi-Roche lobe overflow conditions with high filling factors. We show that, if irradiation feedback occurs and radio ejection inhibits further accretion on to the neutron star after the first mass transfer cycle, the redback systems feature high filling factors. We suggest that the filling factor should be considered as a useful tool for discriminating among those redback formation mechanisms. We compare theoretical results with available observations and conclude that observations tend to favour models with high filling factors.

Close binary systems before and after mass transfer

1982 ◽  
Vol 87 (1-2) ◽  
pp. 377-401 ◽  
Author(s):  
F. Vansina ◽  
J. P. De Grève
Keyword(s):  
Mass Transfer ◽  
Binary Systems ◽  
Close Binary ◽  
Close Binary Systems ◽  
Before And After
Sign in / Sign up

Export Citation Format

Share Document