Exploring the X-ray Emitting Outflowing Winds within Active Galactic Nuclei
Students from Nottingham University Academy of Science and Technology, Nottingham High School and Dr Sam Grafton Waters
Supermassive black holes (SMBHs) at the centre of galaxies can outshine their host galaxy because material, dust and gas, feeds them via the process known as accretion. This accretion process is efficient at converting heat energy, due to the material colliding, into radiation that is emitted across the electromagnetic (EM) spectrum; this is what makes them ‘active’. These types of objects are called active galactic nuclei (AGN) which simply means the supermassive black holes are undergoing this accretion process.
In addition, material is ejected into the host galaxy in the form of very high velocity outflowing winds, due to this violent accretion process. We can study these outflowing winds using X-ray data; the part of the EM spectrum that is very bright in AGN. The signatures in the data of these outflowing winds are narrow emission lines that are produced by specific ions, that are energised by the X-ray photons.
The role of this Orbyts project is to analyse the X-rays from individual AGN to determine how fast the winds are moving, and where they are located with respect to the central SMBH. To do this, we fitted a Gaussian model to each emission line to obtain an observed X-ray wavelength, which we could use to obtain an estimate for the velocity of the wind where this ion was emitted from. From there, we could calculate the possible location of the wind component. The overall aim of this project was to estimate the number of wind components based on this analysis and to see if the locations and velocities differed by comparing the results from different years of the same AGN.
`Over two subsequent years this project produced two scientific papers (one is currently in review), which can be found with other papers from Orbyts projects here: Orbyts Publications