I work as an operation scientist on the Gamma-ray mission Integral in the Science Operations Department of the European Space Agency at ESAC, the European Space Astronomy Centre near Madrid in Spain. My research has been, and still is, firmly anchored to the deepest gravitational well in the Galaxy: Sagittarius A* (Sgr A*). This four-million solar mass black hole whose location defines the nucleus of the Milky Way, is surrounded by a large array of unusal and intimately interacting astrophysical systems. I am interested in the investigation of the ways in which these systems evolve and interact with one another.
What is the source of the hard X-rays around Sgr A* detected by Integral? Is there a relationship between these and the very high energy TeV Gamma-rays detected by Hess? Could the unusal supernova remnant Sgr A East be at the heart of this or maybe the remnant's interaction with the nearby 50 km/s cloud? What the origin of the X-ray, hard X-ray and TeV emission from molecular clouds like Sgr B2 in the central molecular zone? Is there a connection between these, and if so, what is it? How do these dense, giant molecular clouds even form in this environment made hostile by intense radiation fields from massive young stars, the strong magnetic fields, and by the dynamical and gravitational sheers related to the supermassive black hole Sgr A*? How do the very massive stars themselves form in this environment?
Another theme in my research has been the search for periodic or quasi-periodic modulations in the X-ray flux from the central black hole during flares (more details can be found on my research page, under "Timing Analysis"). Why is this interesting: well, any periodic modulation, whether short or long lived, carries a lot of information about the dynamics of a given system. In this case, as in the case of AGN or X-ray binaries, we would be thrilled to find clues about the structure of the material circling around and flowing into the central graviational well. If periodic structures are found in the X-ray flux coming from a region near the black hole, it will inevitably translate directly into knowledge about the extent of the emissive region, the dynamical characteristics of the emitting gas, and in the presence of deviations from what is expected from Keplerian motion, we will gain insight into the actual structure of the spacetime near the central black hole. This is very exciting indeed!
These are some of the questions that motivate my research and investigation of the characteristics of the high energy emission from the central molecular zone of our Galaxy.