Nonthermal THz to TeV Emission from Stellar Wind Shocks in the Galactic Center

The central parsec of the Galaxy contains dozens of massive stars with acumulative mass loss rate of ~ 10^{-3} solar masses per year. Shocks amongthese stellar winds produce the hot plasma that pervades the central part ofthe galaxy. We argue that these stellar wind shocks also efficiently accelerateelectrons and protons to relativistic energies. The relativistic electronsinverse Compton scatter the ambient ultraviolet and far infrared radiationfield, producing high energy gamma-rays with a roughly constant luminosity from\~ GeV to ~ 10 TeV. This can account for the TeV source seen by HESS in theGalactic Center. Our model predicts a GLAST counterpart to the HESS source witha luminosity of ~ 10^{35} ergs/s and cooling break at ~ 4 GeV. Synchrotronradiation from the same relativistic electrons should produce detectableemission at lower energies, with a surface brightness ~ 10^{32} B^2_{-3}ergs/s/arcsec^2 from ~ THz to ~ keV, where B_{-3} is the magnetic fieldstrength in units of mG. The observed level of diffuse thermal X-ray emissionin the central parsec requires B < 300 micro-G in our models. Future detectionof the diffuse synchrotron background in the central parsec can directlyconstrain the magnetic field strength, providing an important boundarycondition for models of accretion onto Sgr A*.Comment: submitted to ApJ Letter