Bright OB stars in the Galaxy IV. Stellar and wind parameters of early to late B supergiants

Abstract

We apply the NLTE atmosphere code FASTWIND to perform a spectroscopic study of a small sample of Galactic B-supergiants from B0 to B9. By means of the resulting data and incorporating additional datasets from alternative studies, we investigate the properties of OB-supergiants and compare our findings with theoretical predictions. As a result we find that due to the combined effects of line- and wind-blanketing, the temperature scale of Galactic B-supergiants needs to be revised downwards, by 10 to 20 percent, the latter value being appropriate for stronger winds. In fair accordance with recent results, our sample furthermore indicates a gradual decrease in wind terminal velocities over the bi-stability region, where the limits of this region are located at lower temperatures than the predicted ones. Introducing a distance-independent quantity Q' related to wind-strength, we also show that this quantity is a well defined, monotonically increasing function of Teff outside this region. Inside and from hot to cool, the mass loss rate changes by a factor (in between 0.4 and 2.5) which is (much) smaller than the predicted factor of 5. All this indicates that the decrease in wind terminal velocity over the bi-stability region is not over-compensated by an increase of mass loss rate, as frequently argued (provided the wind-clumping properties on both sides of this region do not differ substantially).

arXiv comment23 pages and 14 figures accepted for publication in A & A; the Fig. 1 title and the last para of Sec. 4.1 modified; a new reference added

References in corpus (36)

• A Hipparcos census of the nearby OB associations
• Atmospheric NLTE-Models for the Spectroscopic Analysis of Blue Stars with Winds. II. Line-Blanketed Models
• The Discordance of Mass-Loss Estimates for Galactic O-Type Stars
• Physical Parameters and Wind Properties of Galactic Early B Supergiants
• Quantitative Spectroscopy of O Stars at Low Metallicity. O Dwarfs in NGC 346
• Bright OB stars in the Galaxy - III. Constraints on the radial stratification of the clumping factor in hot star winds from a combined Halpha, IR and radio analysis
• Low mass loss rates in O-type stars: Spectral signatures of dense clumps in the wind of two Galactic O4 stars
• The VLT-FLAMES survey of massive stars: Surface chemical compositions of B-type stars in the Magellanic Clouds
• The Physical Properties and Effective Temperature Scale of O-type Stars as a Function of Metallicity. II. Analysis of 20 More Magellanic Cloud Stars, and Results from the Complete Sample
• Revised Stellar Temperatures for Magellanic Cloud O Supergiants from FUSE and VLT-UVES Spectroscopy
• O stars with weak winds: the Galactic case
• Fourier method in the determination of rotational velocities in OB stars
• The VLT-FLAMES survey of massive stars: Mass loss and rotation of early-type stars in the SMC
• Stellar evolution with rotation XIII: Predicted GRB rates at various Z
• Fundamental parameters of Galactic luminous OB stars VI. Temperatures, masses and WLR of Cyg OB2 supergiants
• Understanding B-type Supergiants in the Low Metallicity Environment of the SMC
• Quantitative Spectroscopy of BA-type Supergiants
• Statistical properties of a sample of periodically variable B-type supergiants - Evidence for opacity-driven gravity-mode oscillations
• Fundamental Properties of O-Type Stars
• Understanding B-type supergiants in the low metallicity environment of the SMC II
• The Physical Properties and Effective Temperature Scale of O-type Stars as a Function of Metallicity. I. A Sample of 20 Stars in the Magellanic Clouds
• Puzzling wind properties of young massive stars in SMC-N81
• Catalogue of averaged stellar effective magnetic fields. I. Chemically peculiar A and B type stars
• Chemical composition of B-type supergiants in the OB8, OB10, OB48, OB78 associations of M31
• On the sensitivity of HeI singlet lines to the FeIV model atom in O stars
• B-type supergiants in the SMC: Rotational velocities and implications for evolutionary models
• A pseudo-planar, periodic-box formalism for modelling the outer evolution of structure in spherically expanding stellar winds
• The Effective Temperatures of Hot Stars II. The Early-O Types
• Terminal velocities of luminous, early-type SMC stars
• Quantitative spectral analysis of early B-type supergiants in the Sculptor galaxy NGC 300
• On the Hipparcos parallaxes of O stars
• Mass fluxes for O stars
• Testing the predicted mass-loss bi-stability jump at radio wavelengths
• NLTE models of line-driven stellar winds I. Method of calculation and first results for O stars
• The recent star formation in NGC 6822 from HST imaging
• Hot star wind models with new solar abundances

Cited by in corpus (111)

• Formation of Double Neutron Star Systems
• Mass loss from hot massive stars
• The IACOB project: I. Rotational velocities in Northern Galactic O and early B-type stars revisited. The impact of other sources of line-broadening
• A coordinated X-ray and Optical Campaign of the Nearest Massive Eclipsing Binary, $\delta$ Orionis Aa: IV. A multiwavelength, non-LTE spectroscopic analysis
• A Magnetic Confinement vs. Rotation Classification of Massive-Star Magnetospheres
• A mass of less than 15 solar masses for the black hole in an ultraluminous X-ray source
• The SILCC project: III. Regulation of star formation and outflows by stellar winds and supernovae
• The ephemeris, orbital decay, and masses of 10 eclipsing HMXBs
• The atmospheric parameters and spectral interpolator for the stars of MILES
• The VLT-FLAMES Tarantula Survey - XI. A census of the hot luminous stars and their feedback in 30 Doradus
• The IACOB project: III. New observational clues to understand macroturbulent broadening in massive O- and B-type stars
• Towards a unified view of inhomogeneous stellar winds in isolated supergiant stars and supergiant high mass X-ray binaries
• The VLT-FLAMES Tarantula Survey X: Evidence for a bimodal distribution of rotational velocities for the single early B-type stars
• L-band spectroscopy of Galactic OB-stars
• A comparison of evolutionary tracks for single Galactic massive stars
• Collective pulsational velocity broadening due to gravity modes as a physical explanation for macroturbulence in hot massive stars
• Theory and Diagnostics of Hot Star Mass Loss
• The SILCC project --- IV. Impact of dissociating and ionising radiation on the interstellar medium and Halpha emission as a tracer of the star formation rate
• The population of OB supergiants in the starburst cluster Westerlund 1
• Magnetic massive stars as progenitors of "heavy" stellar-mass black holes
• Wolf-Rayet stars in the Small Magellanic Cloud: II. Analysis of the binaries
• Nitrogen line spectroscopy in O-stars -- II. Surface nitrogen abundances for O-stars in the Large Magellanic Cloud
• The Magnetic Early B-type Stars III: A main sequence magnetic, rotational, and magnetospheric biography
• The nature of B supergiants: clues from a steep drop in rotation rates at 22000 K. The possibility of Bi-stability braking
• On the nature of the galactic early-B hypergiants
• Metallicity-dependent wind parameter predictions for OB stars
• The chemical composition of the Orion star forming region: I. Homogeneity of O and Si abundances in B-type stars
• Fundamental parameters of B Supergiants from the BCD System
• Evolution of blue supergiants and αCygni variables; Puzzling CNO surface abundances
• Spectroscopic determination of the fundamental parameters of 66 B-type stars in the field-of-view of the CoRoT satellite
• The ARAUCARIA project: Grid-Based Quantitative Spectroscopic Study of Massive Blue Stars in NGC55
• Two bi-stability jumps in theoretical wind models for massive stars and the implications for Luminous Blue Variable supernovae
• A VLT/FLAMES survey for massive binaries in Westerlund 1. IV. Wd1-5 - binary product and a pre-supernova companion for the magnetar CXOU J1647-45?
• Nitrogen line spectroscopy of O-stars -- I. Nitrogen III emission line formation revisited
• MOBSTER -- VI. The crucial influence of rotation on the radio magnetospheres of hot stars
• Winds of low-metallicity OB-type stars: HST-COS spectroscopy in IC1613
• A census of massive stars in NGC 346. Stellar parameters and rotational velocities
• SILCC-ZOOM: The early impact of ionizing radiation on forming molecular clouds
• The supergiant optical counterpart of ULX P13 in NGC7793
• Modeling the early evolution of massive OB stars with an experimental wind routine
• Complexes of triggered star formation in supergiant shell of Holmberg II
• Wind-envelope interaction as the origin of the slow cyclic brightness variations of luminous blue variables
• Toward Understanding the B[e] Phenomenon. VII. AS 386, a single-lined binary with a candidate black hole component
• Fast & slow winds from supergiants and Luminous Blue Variables
• Spectroscopic evolution of massive stars on the main sequence
• Quantitative spectroscopy of Galactic BA-type supergiants. I. Atmospheric parameters
• Atmospheric parameters and rotational velocities for a sample of Galactic B-type supergiants
• Theoretical wind clumping predictions of OB supergiants from line-driven instability simulations across the bi-stability jump
• X-Shooting ULLYSES: Massive stars at low metallicity. III. Terminal wind speeds of ULLYSES massive stars
• Spectroscopic and physical parameters of Galactic O-type stars. II. Observational constraints on projected rotational and extra broadening velocities as a function of fundamental parameters and stellar evolution
• Interplay between pulsations and mass loss in the blue supergiant 55 Cygnus = HD 198478
• Multi-epoch Near-Infrared Interferometry of the Spatially Resolved Disk Around the Be Star Zeta Tau
• The theory of stellar winds
• New massive members of Cygnus OB2
• Stochastic light variations in hot stars from wind instability: Finding photometric signatures and testing against the TESS data
• New mass-loss rates of B supergiants from global wind models
• The rotation rates of massive stars: How slow are the slow ones?
• Critical angular velocity and anisotropic mass loss of rotating stars with radiation-driven winds
• On the H$\alpha$ Behaviour of Blue Supergiants: Rise and Fall over the Bi-stability Jump
• Upper Mass-Loss Limits and Clumping in the Intermediate and Outer Wind Regions of OB stars
• A peculiar Of star in the Local Group galaxy IC 1613
• The blue supergiant Sher 25 and its intriguing hourglass nebula
• The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at Solar, LMC, and SMC metallicities
• Time, spatial, and spectral resolution of the Halpha line-formation region of Deneb and Rigel with the VEGA/CHARA interferometer
• How common is LBV S Dor variability at low metallicity?
• Clumping and X-Rays in cooler B supergiant stars
• OB stars at the lowest Local Group metallicity: GTC-OSIRIS observations of Sextans A
• Evolution of rotation in rapidly rotating early-type stars during the main sequence with 2D models
• The B-type Binaries Characterisation Programme II. VFTS 291: A stripped star from a recent mass transfer phase
• Quantitative spectroscopy of B-type supergiants
• The IACOB project IX. Building a modern empirical database of Galactic O9-B9 supergiants: sample selection, description, and completeness
• The IACOB project X. Large-scale quantitative spectroscopic analysis of Galactic luminous blue stars
• Astrophysical parameters of the peculiar X-ray transient IGR J11215-5952
• Low-amplitude rotational modulation rather than pulsations in the CoRoT B-type supergiant HD 46769
• A new reference catalogue for the very metal-poor Universe: +150 OB stars in Sextans A
• The VLT-FLAMES Tarantula Survey XXVII. Physical parameters of B-type main-sequence binary systems in the Tarantula nebula
• X-Shooting ULLYSES: Massive Stars at low metallicity IX: Empirical constraints on mass-loss rates and clumping parameters for OB supergiants in the Large Magellanic Cloud
• Self-consistent solutions for line-driven winds of hot massive stars. The m-CAK procedure
• e-MERLIN 21cm constraints on the mass-loss rates of OB stars in Cyg OB2
• Resolving the clumpy circumstellar environment of the B[e] supergiant LHA 120-S 35
• The IACOB project XI. No increase of mass-loss rates over the bistability region
• The evolution of massive and very massive stars in clusters
• The Wolf-Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud: spectroscopy, orbital analysis, formation, and evolution
• Stellar wind models of central stars of planetary nebulae
• Radiation-Driven Wind Hydrodynamics of Massive Stars: A Review
• The galactic unclassified B[e] star HD 50138 III. The short-term line profile variability of its photospheric lines
• Properties of the Be-type stars in 30 Doradus
• Astrophysical parameters and orbital solution of the peculiar X-ray transient IGR J00370+6122
• An Observational Evaluation of Magnetic Confinement in the Winds of BA Supergiants
• A modern guide to quantitative spectroscopy of massive OB stars
• The H-alpha Variations of the Luminous Blue Variable P Cygni: Discrete Absorption Components and the Short S Doradus Phase
• The Maximum Black Hole Mass at Solar Metallicity
• The blue supergiant Sher 25 revisited in the Gaia era
• To clump or not to clump The impact of wind inhomogeneities on the optical and NIR spectroscopic analysis of massive OB stars
• A model of anisotropic winds from rotating stars for evolutionary calculations
• Blue luminous stars in nearby galaxies - UIT005: a possible link to the luminous blue variable stage
• To the problem of spectral mimicry of supergiants
• The VLT-FLAMES Tarantula Survey XXXII. Low-luminosity late O-type stars -- classification, main physical parameters, and silicon abundances
• Bayesian Statistics as a New Tool for Spectral Analysis: I. Application for the Determination of Basic Parameters of Massive Stars
• Optically-thick Structure in Early B Type Supergiant Stellar Winds at Low Metallicities
• The ultraviolet study of B[e] stars: evidence for pulsations, LBV-type variations, and processes in envelope
• Detection of a 1.59 h period in the B supergiant star HD 202850
• Rotational synchronisation of B-type binaries in 30 Doradus
• Metal-poor single Wolf-Rayet stars: The interplay of optically thick winds and rotation
• The nature of the Cygnus extreme B-supergiant 2MASS J20395358+4222505
• Evolutionary models for the Very Massive Stars in the R136 cluster of 30 Doradus in the Large Magellanic Cloud
• Elemental abundances of the supergiant stars σ Cygnus and η Leonis
• X-Shooting ULLYSES: Massive stars at low metallicity XV. On the metallicity dependence of B-supergiant mass-loss rates
• Micro-turbulence across the Hertzsprung-Russell diagram. Observational constrains for stars in the MW
• Low-frequency spectra of neutron star + OB supergiant binaries: Does wind density drive persistent and flaring modes of accretion?
• Wind structure of late B supergiants I. Multi-line analyses of near-surface and wind structure in HD 199 478 (B8 Iae)