The Ying and Yang of the M 83 Nucleus

MAST, D.; DÍAZ, R.J.; DOTTORI, H.; AGÜERO, M.; RODRIGUES, I.; ALBACETE-COLOMBO, J.F.

Proceedings of the IAU, Symposium

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2010 vol. 267 p. 121 - 121

1743-9213

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.¡å5 (Figure 1). The Pa¦Â 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¡À0.4)¡Á 107 M and MHN = (1.0¡À0.4)¡Á 107 M . Using the Pa¦Â equivalent width together with population synthesis models, we are able to estimate the ages of both mass concentrations, TON = 8 Myr and THN =6¨C7 Myr. Adding complexity to this puzzling scenario, we used GMOS+Gemini imaging and spectroscopy to study the radio source J133658.3¨C295105 (Dottori et al. 2008) and find that H¦Á 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 K¦Á line at 6.7 keV.