IS J 133658.3-295105 A Radio Source at z >= 1.0 or at the Distance of M 83?
Abstract
We present Gemini optical imaging and spectroscopy of the radio source J 133658.3-295105. Thisd source has been suggested to be the core of an FR II radio source with two detected lobes. J 133658.3-295105 and its lobes are aligned with the optical nucleus of M 83 and with three other radio sources at the M 83 bulge outer region. These radio sources are neither supernova remnants nor H II regions. This curious configuration prompted us to try to determine the distance to J 133658.3-295105. We detected Hα emission redshifted by ≈ 130 km s-1 with respect to an M 83 H II region 2farcs5 east-southeast of the radio source. We do not detect other redshifted emission lines of an optical counterpart down to m i = 22.2 ± 0.8. Two different scenarios are proposed: the radio source is at z >= 2.5, a much larger distance than the previously proposed lower limit z >= 1.0, or the object was ejected by a gravitational recoil event from the M 83 nucleus. This nucleus is undergoing a strong dynamical evolution, judging from previous three-dimensional spectroscopy.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 2008
- DOI:
- 10.1088/0004-6256/136/6/2468
- arXiv:
- arXiv:0811.4750
- Bibcode:
- 2008AJ....136.2468D
- Keywords:
-
- galaxies: active;
- galaxies: individual: M 83;
- galaxies: kinematics and dynamics;
- galaxies: nuclei;
- galaxies: starburst;
- Astrophysics
- E-Print:
- 6 pages, 4 figures