Atmospheric parameters and nitrogen abundances to investigate the role of binarity and the width of the main sequence

  title={Atmospheric parameters and nitrogen abundances to investigate the role of binarity and the width of the main sequence},
  author={Catherine M. McEvoy and Philip L. Dufton and C. J. Evans and Venu M. Kalari and Nevena St. Markova and Sergio Sim'on-D'iaz and Jacco Vink and Nolan R. Walborn and Paul A. Crowther and Alex de Koter and Selma E. de Mink and P. R. Dunstall and Vincent H'enault-Brunet and Artemio Herrero and Norbert Langer and Daniel J. Lennon and Jes'us Ma'iz Apell'aniz and Francisco Najarro and Joachim Puls and Hugues Sana and Fabian R. N. Schneider and William D. Taylor},
Context. Model atmosphere analyses have been previously undertaken for both Galactic and extragalactic B-type supergiants. By contrast, little attention has been given to a comparison of the properties of single supergiants and those that are members of multiple systems. Aims. Atmospheric parameters and nitrogen abundances have been estimated for all the B-type supergiants identified in the VLTFLAMES Tarantula survey. These include both single targets and binary candidates. The results have… 
The Origin of B-Type Runaway Stars: Non-LTE Abundances as a Diagnostic
There are two accepted mechanisms to explain the origin of runaway OB-type stars: the Binary Supernova Scenario (BSS), and the Cluster Ejection Scenario (CES). In the former, a supernova explosion
Spectroscopic and physical parameters of Galactic O-type stars. III. Mass discrepancy and rotational mixing
Context. Massive stars play a key role in the evolution of galaxies and our Universe. Aims. Our goal is to compare observed and predicted properties of single Galactic O stars to identify and
Stellar population of the superbubble N 206 in the LMC - I. Analysis of the Of-type stars
Context. Massive stars severely influence their environment by their strong ionizing radiation and by the momentum and kinetic energy input provided by their stellar winds and supernovae.
The VLT-FLAMES Tarantula Survey
Previous analyses of the spectra of OB-type stars in the Magellanic Clouds have identified targets with low projected rotational velocities and relatively high nitrogen abundances; the evolutionary
Impact of binary interaction on the evolution of blue supergiants
A large fraction of massive stars evolve in interacting binary systems, which dramatically modifies the outcome of stellar evolution. We investigated the properties of blue supergiants in binary
The VLT-FLAMES Tarantula Survey
Analysis of late O-type stars observed in the Large Magellanic Cloud (LMC) by the VLT-FLAMES Tarantula Survey revealed a discrepancy between the physical properties estimated from model-atmosphere
The Tarantula Massive Binary Monitoring: I. Observational campaign and OB-type spectroscopic binaries
ontext. Massive binaries play a crucial role in the Universe. Knowing the distributions of their orbital parameters is important for a wide range of topics from stellar feedback to binary evolution
Stellar population of the superbubble N 206 in the LMC
Context. Clusters or associations of early-type stars are often associated with a “superbubble” of hot gas. The formation of such superbubbles is caused by the feedback from massive stars. The
Two bi-stability jumps in theoretical wind models for massive stars and the implications for luminous blue variable supernovae
Luminous Blue Variables have been suggested to be the direct progenitors of supernova types IIb and IIn, with enhanced mass loss prior to explosion. However, the mechanism of this mass loss is not
Massive main sequence stars evolving at the Eddington limit
The evolution of massive stars even on the main sequence is not yet well understood. Due to the steep mass-luminosity relation, massive main sequence stars become very luminous. This brings their


The VLT-FLAMES survey of massive stars: Nitrogen abundances for Be-type stars in the Magellanic Clouds
Aims. We compare the predictions of evolutionary models for early-type stars with atmospheric parameters, projected rotational velocities and nitrogen abundances estimated for a sample of Be-type
Atmospheric parameters and rotational velocities for a sample of Galactic B‐type supergiants
High-resolution optical spectra of 57 Galactic B-type supergiant stars have been analysed to determine their rotational and macroturbulent velocities. In addition, their atmospheric parameters
Understanding B-type supergiants in the low metallicity environment of the SMC
Spectroscopic analyses of 7 SMC B-type supergiants and 1 giant have been undertaken using high resolution optical data obtained on the vlt with uves. fastwind, a non-LTE, spherical, line-blanketed
B-type supergiants in the SMC: Chemical compositions and comparison of static and unified models
High-resolution UCLES/AAT spectra are presented for nine B-type supergiants in the SMC, chosen on the basis that they may show varying amounts of nuclear-synthetically processed material mixed to
Understanding B-type supergiants in the low metallicity environment of the SMC II
Despite a resurgence of effort over the last decade in the area of massive stars there is still ambiguity over their evolutionary path, contamination of their surface abundances and the behaviour of
Nitrogen line spectroscopy of O-stars - II. Surface nitrogen abundances for O-stars in the Large Magellanic Cloud
This is the second paper in a series aiming at the analysis of nitrogen abundances in O-type stars, to enable further constraints on the early evolution of massive stars. We investigate the NIV
An analysis of the optical spectra of the post-asymptotic giant branch stars LSIV -12 111 and HD 341617
High spectral resolution and signal-to-noise observations of the absorption and emission line spectra in two post- asymptotic-giant-branch (PAGB) stellar candidates, LSIV 12 111 and HD 314617 are
Statistical properties of a sample of periodically variable B-type supergiants. Evidence for opacity
Aims: We have studied a sample of 28 periodically variable B-type supergiants selected from the HIPPARCOS mission and 12 comparison stars covering the whole B-type spectral range. Our goal is to test
Quantitative studies of the optical and UV spectra of Galactic early B supergiants - I. Fundamental parameters
Aims. We undertake an optical and ultraviolet spectroscopic analysis of a sample of 20 Galactic B0-B5 supergiants of luminosity classes Ia, Ib, Iab, and II. Fundamental stellar parameters are
Carbon abundance and the N/C ratio in atmospheres of A-, F- and G-type supergiants and bright giants
Based on our prior accurate determination of fundamental parameters for 36 Galactic A-, F- and G-type supergiants and bright giants (luminosity classes I and II), we undertook a non-LTE analysis of