scholarly journals The Tarantula Massive Binary Monitoring

2020 ◽  
Vol 634 ◽  
pp. A118 ◽  
Author(s):  
L. Mahy ◽  
H. Sana ◽  
M. Abdul-Masih ◽  
L. A. Almeida ◽  
N. Langer ◽  
...  
Keyword(s):  
Binary Systems ◽  
Tidal Mixing ◽  
Spectroscopic Binaries ◽  
Type Star ◽  
Evolutionary Models ◽  
Test Bed ◽  
Contact Phase ◽  
Single Star ◽  
Massive Binary Systems ◽  
The Individual

Context. Accurate stellar parameters of individual objects in binary systems are essential to constrain the effects of binarity on stellar evolution. These parameters serve as a prerequisite to probing existing and future theoretical evolutionary models. Aims. We aim to derive the atmospheric parameters of the 31 double-lined spectroscopic binaries in the Tarantula Massive Binary Monitoring sample. This sample, composed of detached, semi-detached and contact systems with at least one of the components classified as an O-type star, is an excellent test-bed to study how binarity can impact our knowledge of the evolution of massive stars. Methods. In the present paper, 32 epochs of FLAMES/GIRAFFE spectra are analysed by using spectral disentangling to construct the individual spectra of 62 components. We then apply the CMFGEN atmosphere code to determine their stellar parameters and their helium, carbon, and nitrogen surface abundances. Results. Among the 31 systems that we study in the present paper, we identify between 48 and 77% of them as detached, likely pre-interacting systems, 16% as semi-detached systems, and between 5 and 35% as systems in or close to contact phase. Based on the properties of their components, we show that the effects of tides on chemical mixing are limited. Components on longer-period orbits show higher nitrogen enrichment at their surface than those on shorter-period orbits, in contrast to expectations of rotational or tidal mixing, implying that other mechanisms play a role in this process. For semi-detached systems, components that fill their Roche lobe are mass donors. They exhibit higher nitrogen content at their surface and rotate more slowly than their companions. By accreting new material, their companions spin faster and are likely rejuvenated. Their locations in the N − v sin i diagram tend to show that binary products are good candidates to populate the two groups of stars (slowly rotating, nitrogen-enriched objects and rapidly rotating non-enriched objects) that cannot be reproduced through single-star population synthesis. Finally, we find no peculiar surface abundances for the components in (over-)contact systems, as has been suggested by evolutionary models for tidal mixing. Conclusions. This sample, consisting of 31 massive binary systems, is the largest sample of binaries composed of at least one O-type star to be studied in such a homogeneous way by applying spectral disentangling and atmosphere modelling. The study of these objects gives us strong observational constraints to test theoretical binary evolutionary tracks.

scholarly journals The Tarantula Massive Binary Monitoring

2020 ◽  
Vol 634 ◽  
pp. A119 ◽  
Author(s):  
L. Mahy ◽  
L. A. Almeida ◽  
H. Sana ◽  
J. S. Clark ◽  
A. de Koter ◽  
...  
Keyword(s):  
Binary Systems ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Spectroscopic Binaries ◽  
Systematic Analysis ◽  
Orbital Parameters ◽  
The Individual ◽  
30 Doradus ◽  
Dynamical Masses

Context. A high fraction of massive stars are found to be binaries but only a few of them are reported as photometrically variable. By studying the populations of double-lined spectroscopic binaries in the 30 Doradus region, we found a subset of them that have photometry from the OGLE project and that display variations in their light curves related to orbital motions. Aims. The goal of this study is to determine the dynamical masses and radii of the 26 binary components in order to investigate the mass-discrepancy problem and to provide an empirical mass-luminosity relation for the Large Magellanic Cloud (LMC). Methods. We use the PHOEBE programme to perform a systematic analysis of the OGLE V and I light curves obtained for 13 binary systems in the 30 Doradus region. We adopt the effective temperatures, and orbital parameters derived previously to obtain the inclinations of the systems and the parameters of the individual components. Results. Three systems display eclipses in their light curves, while the others only display ellipsoidal variations. We classify two systems as over-contact, five as semi-detached, and four as detached. The two remaining systems have uncertain configurations due to large uncertainties on their inclinations. The fact that systems display ellipsoidal variations has a significant impact on the inclination errors. From the dynamical masses, luminosities, and radii, we provide LMC-based empirical mass-luminosity and mass-radius relations, and we compare them to other relations given for the Galaxy, the LMC, and the Small Magellanic Cloud. These relations differ for different mass ranges, but do not seem to depend on the metallicity regimes. We also compare the dynamical, spectroscopic, and evolutionary masses of the stars in our sample. While the dynamical and spectroscopic masses agree with each other, the evolutionary masses are systematically higher, at least for stars in semi-detached systems. This suggests that the mass discrepancy can be partly explained by past or ongoing interactions between the stars.

scholarly journals Non-synchronous rotations in massive binary systems

2018 ◽  
Vol 618 ◽  
pp. A174
Author(s):  
C. Putkuri ◽  
R. Gamen ◽  
N. I. Morrell ◽  
S. Simón-Díaz ◽  
R. H. Barbá ◽  
...  
Keyword(s):  
Binary Systems ◽  
Massive Stars ◽  
Spectroscopic Binaries ◽  
Evolutionary Status ◽  
Multiple Systems ◽  
Orbital Parameters ◽  
Link Type ◽  
Tidal Forces ◽  
Relative Separation ◽  
Massive Binary Systems

Context. Most massive stars are in binary or multiple systems. Several massive stars have been detected as double-lined spectroscopic binaries and among these, the OWN Survey has detected a non-negligible number whose components show very different spectral line broadening (i.e., projected rotational velocities). This fact raises a discussion about the contributing processes, such as angular-momentum transfer and tidal forces. Aims. We seek to constrain the physical and evolutionary status of one of such systems, the O+O binary HD 93343. Methods. We analyzed a series of high-resolution multiepoch optical spectra to determine the orbital parameters, projected rotational velocities, and evolutionary status of the system. Results. HD 93343 is a binary system comprised of two O7.5 Vz stars that each have minimum masses of approximately 22 M⊙ in a wide and eccentric orbit (e = 0.398±0.004; P = 50.432±0.001 d). Both stars have very similar stellar parameters, and hence ages. As expected from the qualitative appearance of the combined spectrum of the system, however, these stars have very different projected rotational velocities (~65 and ~325 km s−1, respectively). Conclusions. The orbits and stellar parameters obtained for both components seem to indicate that their youth and relative separation is enough to discard the effects of mass transfer and tidal friction. Thus, non-synchronization should be intrinsic to their formation.

scholarly journals Evolution of Progenitor Stars of Type Ibc Supernovae and Long Gamma-Ray Bursts

2007 ◽  
Vol 3 (S250) ◽  
pp. 231-236
Author(s):  
Sung-Chul Yoon ◽  
Norbert Langer ◽  
Matteo Cantiello ◽  
Stan E. Woosley ◽  
Gary A. Glatzmaier
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Massive Star ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Evolutionary Models ◽  
Single Star ◽  
Solar Metallicity ◽  
Progenitor Stars

AbstractWe discuss how rotation and binary interactions may be related to the diversity of type Ibc supernovae and long gamma-ray bursts. After presenting recent evolutionary models of massive single and binary stars including rotation, the Tayler-Spruit dynamo and binary interactions, we argue that the nature of SNe Ibc progenitors from binary systems may not significantly differ from that of single star progenitors in terms of rotation, and that most long GRB progenitors may be produced via the quasi-chemically homogeneous evolution at sub-solar metallicity. We also briefly discuss the possible role of magnetic fields generated in the convective core of a massive star for the transport of angular momentum, which is potentially important for future stellar evolution models of supernova and GRB progenitors.

scholarly journals Probing high-mass stellar evolutionary models with binary stars

2014 ◽  
Vol 9 (S307) ◽  
pp. 200-205
Author(s):  
A. Tkachenko
Keyword(s):  
Detailed Analysis ◽  
Stellar Evolution ◽  
Binary Stars ◽  
Binary Systems ◽  
State Of The Art ◽  
Binary Star ◽  
Research Field ◽  
High Mass ◽  
Evolutionary Models ◽  
Massive Binary Systems

AbstractMass discrepancy is one of the problems that is pending a solution in (massive) binary star research field. The problem is often solved by introducing an additional near core mixing into evolutionary models, which brings theoretical masses of individual stellar components into an agreement with the dynamical ones. In the present study, we perform a detailed analysis of two massive binary systems, V380 Cyg and σ Sco, to provide an independent, asteroseismic measurement of the overshoot parameter, and to test state-of-the-art stellar evolution models.

scholarly journals Evolutionary Models for Type Ib/c Supernova Progenitors

2015 ◽  
Vol 32 ◽  
Author(s):  
Sung-Chul Yoon
Keyword(s):  
Binary Systems ◽  
Early Time ◽  
Light Curves ◽  
Evolutionary Models ◽  
Stellar Rotation ◽  
Test Bed ◽  
Host Galaxies ◽  
Physical Processes ◽  
Binary Evolution ◽  
Single And Binary Systems

AbstractSNe Ib/c mark the deaths of hydrogen-deficient massive stars. The evolutionary scenarios for SNe Ib/c progenitors involve many important physical processes including mass loss by winds and its metallicity dependence, stellar rotation, and binary interactions. This makes SNe Ib/c an excellent test bed for stellar evolution theory. We review the main results of evolutionary models for SN Ib/c progenitors available in the literature and their confrontation with recent observations. We argue that the nature of SN Ib/c progenitors can be significantly different for single and binary systems, and that binary evolution models can explain the ejecta masses derived from SN Ib/c light curves, the distribution of SN Ib/c sites in their host galaxies, and the optical magnitudes of the tentative progenitor candidate of iPTF13bvn. We emphasise the importance of early-time observations of light curves and spectra, accurate measurements of helium mass in SN Ib/c ejecta, and systematic studies about the metallicity dependence of SN Ib/c properties, to better constrain theories.

scholarly journals The evolution of massive binary systems

2020 ◽  
pp. 1-13
Author(s):  
Jelena Petrovic
Keyword(s):  
Binary Systems ◽  
Gamma Ray ◽  
Massive Stars ◽  
Compact Objects ◽  
Close Binary ◽  
Extensive Literature ◽  
Single Star ◽  
Close Binary Systems ◽  
Massive Binary Systems ◽  
Massive Close Binary

The evolution of massive stars in close binary systems is significantly different from single star evolution due to a series of interactions between the two stellar components. Such massive close binary systems are linked to various astrophysical phenomena, for example Wolf-Rayet stars, supernova type Ib and Ic, X-ray binaries and gamma-ray bursts. Also, the emission of gravitational waves, recently observed by the LIGO-Virgo detectors, is associated with mergers in binary systems containing compact objects, relics of massive stars - black holes and neutron stars. Evolutionary calculations of massive close binary systems were performed by various authors, but many aspects are not yet fully understood. In this paper, the main concepts of massive close binary evolution are reviewed, together with the most important parameters that can influence the final outcome of the binary system evolution, such as rotation, magnetic fields, stellar wind mass loss and mass accretion efficiency during interactions. An extensive literature overview of massive close binary models in the light of exciting observations connected with those systems is presented.

scholarly journals Metallicity dependence of Type Ib/c and IIb supernova progenitors in binary systems

2015 ◽  
Vol 11 (A29B) ◽  
pp. 212-212
Author(s):  
Sung-Chul Yoon
Keyword(s):  
Mass Loss ◽  
Binary Stars ◽  
Binary Systems ◽  
Evolutionary Models ◽  
Single Star ◽  
Theoretical Predictions ◽  
Solar Metallicity ◽  
Low Metallicity ◽  
Hydrogen Lines ◽  
High Metallicity

AbstractType Ib/c supernovae (SNe Ib/c) are characterized by the lack of prominent hydrogen lines in thespectra, implying that their progenitors have lost most of their hydrogen envelopes by the time of the iron corecollapse. Binary interactions provide an important evolutionary chanel for SNe Ib/c, and recent observations indicatethat the inferred ejecta masses of SNe Ibc are more consistent with the prediction of the binary scenario than that ofthe single star scenario that invokes mass loss as the key evolutionary factor for SNe Ib/c progenitors. So far,theoretical predictions on the detailed properties of SNe Ib/c progenitors in binary systems have been made mostlywith models using solar metallicity. However, unlike the single star scenario, where SNe Ib/c are expected only forsufficiently high metallicity, hydrogen-deficent SN progenitors can be produced via binary interactions at anymetallicity. In this talk, I will discuss theoretical predictions on the metallicity dependence of the SNe Ib/c progenitorstructure, based on evolutionary models of massive binary stars. Sepefically, I will address how the ejecta masses ofSNe Ib and Ic and the ratio of SN Ib/c to SN IIb as well as SN Ib to SN Ic would systematically change as a function ofmetallicity, and which new types of SNe are expected in binary systems at low metallicity.

scholarly journals The Close Binary Frequency of Wolf-Rayet Stars as a Function of Metallicity in M31 and M33

2014 ◽  
Vol 9 (S307) ◽  
pp. 127-128
Author(s):  
Kathryn F. Neugent ◽  
Philip Massey
Keyword(s):  
Binary Systems ◽  
Roche Lobe ◽  
Close Binary ◽  
Evolutionary Models ◽  
Single Star ◽  
Close Binary Systems

AbstractHere we investigate whether the inability of the Geneva evolutionary models to predict a large enough WC/WN ratio at high metallicities (while succeeding at lower metallicities) is due to their single star nature. We hypothesize that Roche-lobe overflow in close binary systems may produce a greater number of WC stars at higher metallicities. But, this would suggest that the frequency of close massive binaries is metallicity dependent. We now present our results based on observations of ~100 Wolf-Rayet binaries in the varying metallicity environments of M31 and M33.

scholarly journals The Remarkable Evolution of the Post-Agb Star FG SGE

1998 ◽  
Vol 11 (1) ◽  
pp. 363-363
Author(s):  
Johanna Jurcsik ◽  
Benjamin Montesinos
Keyword(s):  
Time Scales ◽  
Effective Temperature ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Central Star ◽  
Evolutionary Models ◽  
Single Star ◽  
Line Intensities ◽  
Evolutionary Changes ◽  
Evolutionary Studies

FG Sagittae is one of the most important key objects of post-AGB stellar evolutionary studies. As a consequence of a final helium shell flash, this unique variable has shown real evolutionary changes on human time scales during this century. The observational history was reviewed in comparison with predictions from evolutionary models. The central star of the old planetary nebula (Hel-5) evolved from left to right in the HR diagram, going in just hundred years from the hot region of exciting sources of planetary nebulae to the cool red supergiant domain just before our eyes becoming a newly-born post-AGB star. The effective temperature of the star was around 50,000 K at the beginning of this century, and the last estimates in the late 1980s give 5,000-6,500 K. Recent spectroscopic observations obtained by Ingemar Lundström show definite changes in the nebular line intensities. This fact undoubtedly rules out the possibility that, instead of FG Sge, a hidden hot object would be the true central star of the nebula. Consequently, the observed evolutionary changes are connected with the evolution of a single star.

A Screw-Theoretic Analysis Framework for Payload Manipulation by Mobile Manipulator Collectives

2005 ◽  
Author(s):  
Rajankumar Bhatt ◽  
Chin Pei Tang ◽  
Michel Abou-Samah ◽  
Venkat Krovi
Keyword(s):  
System Performance ◽  
Single Agent ◽  
Physical Nature ◽  
Theoretical Background ◽  
System Level ◽  
Mobile Manipulator ◽  
Test Bed ◽  
Tight Coupling ◽  
Constrained Mechanical Systems ◽  
The Individual

In recent times, there has been considerable interest in creating and deploying modular cooperating collectives of robots. Interest in such cooperative systems typically arises when certain tasks are either too complex to be performed by a single agent or when there are distinct benefits that accrue by cooperation of many simple robotic modules. However, the nature of the both the individual modules as well as their interactions can affect the overall system performance. In this paper, we examine this aspect in the context of cooperative payload transport by robot collectives wherein the physical nature of the interactions between the various modules creates a tight coupling within the system. We leverage the rich theoretical background of analysis of constrained mechanical systems to provide a systematic framework for formulation and evaluation of system-level performance on the basis of the individual-module characteristics. The composite multi-d.o.f wheeled vehicle, formed by supporting a common payload on the end-effectors of multiple individual mobile manipulator modules, is treated as an in-parallel system with articulated serial-chain arms. The system-level model, constructed from the twist- and wrench-based models of the attached serial chains, can then be systematically analyzed for performance (in terms of mobility and disturbance rejection.) A 2-module composite system example is used through the paper to highlight various aspects of the systematic system model formulation, effects of selection of the actuation at the articulations (active, passive or locked) on system performance and experimental validation on a hardware prototype test bed.

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