Since I began my PhD studies the main project has been to uncover a fascinating tale about how the X-ray source LMC X-3 located in the Large Magellanic Cloud has been formed into the system we see today. The system today consists of a star and a black hole. The X-rays we observe are generated because the star has left the main sequence and started inflating. In consequence of this it has reached the so-called Roche radius which is the distance from the star at which point the gravity between the star and the black are equal. Since the star wants to expand beyond the roche lobe it looses mass which is transferred onto the black hole. Once the material reaches the black hole and is accreted, it emits energetic radiation in the form of X-rays.
In our paper you may find the full story about LMC X-3. Here is a link to the paper; Unraveling the formation history of the black hole X-ray binary LMC X-3 from the zero age main sequence to the present.