Testing the Radiatively Inefficient Accretion Flow Model for Sagittarius A* Using the Size Measurements

The Astrophysical Journal (Impact Factor: 6.28). 12/2008; 642(1):L45. DOI: 10.1086/504475
Source: arXiv

ABSTRACT Recent radio observations by the Very Long Baseline Array at 7 and 3.5 mm produced the high-resolution images of the compact radio source located at the center of our Galaxy (Sgr A*) and detected its wavelength-dependent intrinsic sizes at the two wavelengths. This provides us with a good chance of testing previously proposed theoretical models for Sgr A*. In this Letter, we calculate the size based on the radiatively inefficient accretion flow (RIAF) model proposed by Yuan, Quataert, & Narayan. We find that after taking into account the scattering of the interstellar electrons, the predicted sizes are consistent with the observations. We further predict an image of Sgr A* at 1.3 mm that can be tested by future observations.

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