Obtaining an accurate position for a new radio-bright ULX in M31

Understanding the causal link between the accretion disc around black holes and the production of powerful jet events is one of the outstanding issues in accretion physics. Through the discovery of the first jetted ultraluminous X-ray source (ULX) in M31, we have shown that both the accretion disc and jets can be studied by current instrumentation, opening the way for understanding the jet launching. We request a pre-approved, 2 ks ToO with the HRC-I to determine an accurate position for a new ULX discovered with pre-approved X-ray monitoring of M31 (with Swift) to be compared to the VLA position of the radio source. Showing the two to be spatially coincident is vital for such studies and only Chandra has the capability to do so.