Does Sgr A* Have an Intrinsic Magnetic Moment Instead of an Event Horizon?

Abstract

In previous work we have developed a general relativistic, magnetospheric eternally collapsing object (MECO) model for black hole candidates and shown that the model is consistent with broad band spectral and luminosity characteristics and accounts for the radio/x-ray luminosity correlations of both galactic black hole candidates (GBHC) and active galactic nuclei (AGN). We show here that the MECO model can: a) satisfy the luminosity constraints that have been claimed as proof of an event horizon for Sgr A*, b) reconcile the low bolometric luminosity with the expected Bondi accretion rate for Sgr A* by means of a magnetic propeller driven outflow, c) account for the Sgr A* NIR and x-ray luminosities, the general characteristics of its broad band spectrum, and the sequence of flares in different spectral ranges as well as the pattern of its observed orthogonal polarizations. We also include specific predictions for images that may be obtained in sub-millimeter to NIR wavelengths in the near future. Additional future tests for the presence of an intrinsic magnetic moment for Sgr A* will require global solutions for electron density and magnetic field distributions in a Bondi accretion flow into a compact, rotating magnetic dipole. These will provide for definitive tests in the form of detailed calculations of spectral and spatial luminosity distributions and polarization maps for direct comparison with high resolution images of Sgr A*.