The Ying and Yang of the M 83 Nucleus

MAST, DAMIAN; DÍAZ, RUBÉN J.; DOTTORI, HORACIO; AGUERO, MARIA P.; RODRIGUES, IRAPUAN; ALBACETE-COLOMBO, JUAN FACUNDO

Rio de Janeiro

Simposio; Co-Evolution of Central Black Holes and Galaxies Proceedings; 2010

The spiral galaxy M 83, an SB(rs)b at only 4.5 Mpc, is a privileged case for study of the detailed physics on spatial scales of a tenth of a parsec. With 3-D spectroscopic observations using CIRPASS on Gemini-S, we studied the ionized gas properties in J-band with spatial resolution of 0.''5 (Figure 1). The Pa_beta velocity field shows two dynamical centers, neither of them coincident with the bulge center, identified with the optical nucleus (ON) and the hidden nucleus (HN), with masses, within a radius of 10 pc, of MON = (1.8±0.4)× 107 Msun and MHN = (1.0±0.4)× 107 Msun. Using the Pa_beta equivalent width together with population synthesis models, we are able to estimate the ages of both mass concentrations, TON = 8 Myr and THN =6-7 Myr. Adding complexity to this puzzling scenario, we used GMOS+Gemini imaging and spectroscopy to study the radio source J133658.3-295105 (Dottori et al. 2008) and find that Hα emission at the position of this source is redshifted by ~130 km s-1 with respect to an M 83 H II region, leading us to face the possibility of that we are witnessing the ejection of an object by gravitational recoil from the M 83 nucleus. A fit to the X-ray spectrum obtained Chandra supports the association between this source and the disk of M 83 by the presence of the Fe Kalpha line at 6.7 keV.