The missing goliath's slingshot : massive black hole recoil at M83

Abstract

The Fanaroff–Riley II radio source J133658.3−295105, which is also an X-ray source, appears to be projected onto the disk of the barred-spiral galaxy M83 at about 60" from the galaxy’s optical nucleus. J133658.3−295105 and its radio lobes are aligned with the optical nucleus of M83 and two other radio sources, neither of which are supernova remnants or H II regions. Due to this peculiar on-the-sky projection, J133658.3−295105 was previously studied by Gemini+GMOS optical spectroscopy, which marginally revealed the presence of Hα in emission receding at 130 km s-ˡ with respect to the optical nucleus. In this Letter, we reanalyze the Chandra spectroscopy carried out in 2000. We show that J133658.3−295105 presents an Fe Kα emission line at a redshift of z = 0.018. This redshift is compatible with a black hole at the distance of M 83. We discuss similarities to the recently reported micro-quasar in NGC 5408. This finding reinforces the kicked-off black hole scenario for J133658.3−295105.