Revisiting the Evolutionary Status of Massive Stars at the central parsec of the Milky Way

Abstract

Massive stars and their winds have a large influence in their environment, e.g, determining the accretion rate on to the Galactic Centre (GC) super-massive black hole Sgr A*. The winds of those stars collide and are accreted, at a rate that depends on their chemical composition. Here we aim to revisit the evolutionary status of the evolved massive stars at the GC, by means of new tracks based on updated mass-loss rate recipes for the earlier stages of massive stars. We use the Geneva-evolution-code for initial stellar masses ranging from 20 to 60 $M_{\odot }$, for metallicity $Z=0.020$. We adopt a new mass-loss rate recipe for the line-driven winds of O-type stars and B-supergiants, plus a new recipe for the dust-driven winds of red supergiants (RSG). Additionally, we set up initial rotation $\Omega /{\Omega }_{\text{crit}}=0.4$, and we adopt the Ledoux criterion for the treatment of convection in inner layers. We found that evolution models adopting new mass-loss rate prescriptions predict that stars will lose less of their outer layers during their initial phases, while a big reduction of mass happens at the RSG phase. As a consequence, the resulting Wolf-Rayet (WR) stars are less radially homogeneous in their inner structure from the core to the surface. Also, these new evolution models predict the absence of hydrogen-free WN stars. These evolutionary predictions agree better with the observed chemical abundances of the WR stars at the GC. We provide a table with the chemical H, He, and CNO abundances calculated for the different subtypes of WR stars. We propose a different re-arrangement of the WR subtypes to be used for the modelling of the collision of their winds. We discuss the potential implications of these changes for the colliding winds generated from the massive stars at the GC, which are accreting onto the supermassive black hole Sgr A*.

Accepted for publication at A&A Journal

References in corpus (51)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Physical Properties of Wolf-Rayet Stars
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• Mass loss from late-type WN stars and its Z-dependence: very massive stars approaching the Eddington limit
• Stellar and wind properties of massive stars in the central parsec of the Galaxy
• The wind speeds, dust content, and mass-loss rates of evolved AGB and RSG stars at varying metallicity
• On the nature of massive helium star winds and Wolf-Rayet-type mass loss
• The impact of mass-loss on the evolution and pre-supernova properties of red supergiants
• Variable accretion and emission from the stellar winds in the Galactic centre
• Twelve years of spectroscopic monitoring in the Galactic Center: the closest look at S-stars near the black hole
• Evolution of surface CNO abundances in massive stars
• The Surprisingly Small Impact of Magnetic Fields On The Inner Accretion Flow of Sagittarius A* Fueled By Stellar Winds
• Accretion of cool stellar winds on Sgr A*: another puzzle of the Galactic Centre?
• The young stars in the Galactic Center
• A Cool Accretion Disk around the Galactic Centre Black Hole
• Analytic, dust-independent mass-loss rates for red supergiant winds initiated by turbulent pressure
• Evolved Massive Stars at Low-metallicity V. Mass-Loss Rate of Red Supergiant Stars in the Small Magellanic Cloud
• Grids of stellar models with rotation VII: Models from 0.8 to 300 M${}_{\odot }$ at super-solar metallicity (Z = 0.020)
• Mass loss and the Eddington parameter: a new mass-loss recipe for hot and massive stars
• The temperature dependency of Wolf-Rayet-type mass loss: An exploratory study for winds launched by the hot iron bump
• Stellar winds pump the heart of the Milky Way
• Episodic Gaseous Outflows and Mass Loss from Red Supergiants
• ALMA detection of CO rotational line emission in red supergiant stars of the massive young star cluster RSGC1 -- Determination of a new mass-loss rate prescription for red supergiants
• The role of feedback in accretion on Low Luminosity AGN: Sgr A* case study
• Establishing a mass-loss rate relation for red supergiants in the Large Magellanic Cloud
• New mass-loss rates of B supergiants from global wind models
• WO-Type Wolf-Rayet Stars: the Last Hurrah of Massive Star Evolution
• Evolutionary tracks, ejecta, and ionizing photons from intermediate-mass to very massive stars with PARSEC
• Red Supergiants in M31: The Humphreys-Davidson limit at high metallicity
• Very Massive Star Models: I. Impact of Rotation and Metallicity and Comparisons with Observations
• The effect of mass loss in models of red supergiants in the Small Magellanic Cloud
• Colliding Winds in and around the Stellar Group IRS 13E at the Galactic Center
• Evolution of massive stars with new hydrodynamic wind models
• Self-consistent solutions for line-driven winds of hot massive stars. The m-CAK procedure
• 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
• Red Supergiant Mass Loss and Mass-Loss Rates
• The IACOB project XI. No increase of mass-loss rates over the bistability region
• Impact of main-sequence mass loss on the appearance, structure and evolution of Wolf-Rayet stars
• The impact of convective criteria on the properties of massive stars
• The Formation of Black Holes in Non-interacting, Isolated Binaries. Gaia Black Holes as Calibrators of Stellar Winds From Massive Stars
• Evolution of rotating massive stars with new hydrodynamic wind models
• Signatures of Rapidly Rotating Stars with Chemically Homogeneous Evolution in the First Galaxies
• Evolution of rotating massive stars adopting a newer, self-consistent wind prescription at SMC metallicity
• New self-consistent wind parameters fitting optical spectra of O-type stars observed with HERMES spectrograph
• Upper Limit on Brackett-gamma Emission from the Immediate Accretion Flow onto the Galactic Black Hole
• Investigating the metallicity dependence of the mass-loss rate relation of red supergiants
• Exploring the connection between atmosphere models and evolution models of very massive stars
• The formation and stability of a cold disc made out of stellar winds in the Galactic Centre
• X-Shooting ULLYSES: Massive Stars at Low Metallicity X. Physical Parameters and Feedback of Massive Stars in the LMC N11 B Star-Forming Region
• Evolution of stars with 60 and 200 Msun: predictions for WNh stars in the Milky Way
• Compact stellar systems hosting an intermediate mass black hole: magnetohydrodynamic study of inflow-outflow dynamics