Slow Radiation-Driven Wind Solutions of A-Type Supergiants

Abstract

The theory of radiation-driven winds succeeded in describing terminal velocities and mass loss rates of massive stars. However, for A-type supergiants the standard m-CAK solution predicts values of mass loss and terminal velocity higher than the observed values. Based on the existence of a slow wind solution in fast rotating massive stars, we explore numerically the parameter space of radiation-driven flows to search for new wind solutions in slowly rotating stars, that could explain the origin of these discrepancies. We solve the 1-D hydrodynamical equation of rotating radiation-driven winds at different stellar latitudes and explore the influence of ionization's changes throughout the wind in the velocity profile. We have found that for particular sets of stellar and line-force parameters, a new slow solution exists over the entire star when the rotational speed is slow or even zero. In the case of slow rotating A-type supergiant stars the presence of this novel slow solution at all latitudes leads to mass losses and wind terminal velocities which are in agreement with the observed values. The theoretical Wind Momentum-Luminosity Relationship derived with these slow solutions shows very good agreement with the empirical relationship. In addition, the ratio between the terminal and escape velocities, which provides a simple way to predict stellar wind energy and momentum input into the interstellar medium, is also properly traced.

7 Pages, 3 figures, Astrophysical Journal, Accepted

References in corpus (6)

• Mass loss from hot massive stars
• Physical Parameters and Wind Properties of Galactic Early B Supergiants
• The influence of rotation in radiation driven wind from hot stars: New solutions and disk formation in Be stars
• Outflowing disk formation in B[e] supergiants due to rotation and bi--stability in radiation driven winds
• Testing the predicted mass-loss bi-stability jump at radio wavelengths
• The ionization structure of early-B supergiant winds

Cited by in corpus (14)

• EChO - Exoplanet Characterisation Observatory
• Not-So-Simple Stellar Populations in the Intermediate-age Large Magellanic Cloud Star Clusters NGC 1831 and NGC 1868
• Inhomogeneous molecular ring around the B[e] supergiant LHA 120-S 73
• Self-consistent solutions for line-driven winds of hot massive stars. The m-CAK procedure
• Radiation-Driven Wind Hydrodynamics of Massive Stars: A Review
• CoRoT-22 b: a validated 4.9 RE exoplanet in 10-day orbit
• Search for exoplanets and brown dwarfs with VLBI
• New self-consistent wind parameters fitting optical spectra of O-type stars observed with HERMES spectrograph
• Wind properties of variable B supergiants. Evidence of pulsations connected with mass-loss episodes
• $\Omega$-Slow Solutions and Be Star Disks
• Analytical Solutions for Radiation-Driven Winds in Massive Stars. I: The Fast Regime
• Limb-Darkened Radiation-Driven Winds from Massive Stars
• Forecasting the detectability of known radial velocity planets with the upcoming CHEOPS mission
• X-Shooting ULLYSES: Massive stars at low metallicity XV. On the metallicity dependence of B-supergiant mass-loss rates