Massive stars blow powerful stellar winds throughout their evolutionary stages from the main sequence to Wolf-Rayet phases. The amount of mechanical energy deposited in the interstellar medium by the wind from a massive star can be comparable to the explosion energy of a core-collapse supernova that detonates at the end of its life. In this study, we estimate the kinetic energy deposition by massive stars in our Galaxy by considering the integrated Galactic initial mass function and modeling the stellar wind luminosity. The mass loss rate and terminal velocity of stellar winds during the main sequence, red supergiant, and Wolf-Rayet stages are estimated by adopting theoretical calculations and observational data published in the literature. We find that the total stellar wind luminosity due to all massive stars in the Galaxy is about Lw ≈ 1.1 × 1041 erg s−1, which is about 1/4 of the power of supernova explosions, LSN ≈ 4.8 × 1041 erg s−1. If we assume that ∼ 1 − 10 % of the wind luminosity could be converted to Galactic cosmic rays (GCRs) through collisonless shocks such as termination shocks in stellar bubbles and superbubbles, colliding-wind shocks in binaries, and bow-shocks of massive runaway stars, stellar winds might be expected to make a significant contribution to GCR production, though lower than that of supernova remnants.

Abstract
1. INTRODUCTION
2. MODELS
    2.1. Integrated Galactic Initial Mass Function
    2.2. Massive Star Evolution
    2.3. MS and WR Winds
    2.4. RSG Winds
    2.5. Wind Luminosity
3. RESULTS
    3.1. Wind Energy Deposition
    3.2. Wind Luminosity of the Galaxy
4. SUMMARY
REFERENCES

• Jeongbhin Seo(Department of Earth Sciences, Pusan National University)
• Hyesung Kang(Department of Earth Sciences, Pusan National University) Corresponding author
• Dongsu Ryu(Department of Physics, School of Natural Sciences, UNIST)