Speaker
Description
Ultraluminous X-ray sources (ULXs) are a class of extreme X-ray binaries, most of them powered by super-Eddington accretion onto stellar mass black holes and neutron stars. Extended optical or radio emission (and a single case in X-rays) has been observed around some ULXs, with a bubble-like shape. These huge bubbles have diameters > 100 pc and contain an energy 10-100 times larger than the energy content of supernova remnants. ULX bubbles are thought to be shock-ionized, formed by the interaction of ULX outflows (winds or jets) with the surrounding interstellar medium. The study of ULX bubbles is crucial to understand the feedback of these extreme accretors on the surrounding environment.
In this talk, I will focus on the results obtained from the analysis of a MeerKAT dataset of the ULX bubble around NGC 1313 X2, which is the first radio detection of this bubble, previously observed only in the optical. At least two different emitting regions can be identified in the radio map, one brighter and one weaker, with a compact and a steep spectral shape, respectively. The bubble dimension as seen in the radio is consistent with the Halpha emission from MUSE data: I will show a comparison of the morphology at radio and optical wavelengths. Finally, I will discuss the results from the study of this bubble in a larger context, including a comparison with Galactic X-ray binaries, first of all the extreme SS433 and its W50 nebula.