The view through the wind

by Gallagher, Sarah Connoran.

The 2–10 keV bandpasses and unprecedented sensitivity of modern X-ray observatories have enabled new insights into the immediate environments of Broad Absorption Line (BAL) QSOs. BAL QSOs, approximately 10% of the QSO population, exhibit deep, broad absorption lines from high ionization ultraviolet resonance transitions. These blueshifted absorption features are understood to arise along lines of sight which travel through radiatively driven winds with terminal velocities reaching 0.1–0.3c. These energetic outflows are an important component of QSO environments; mass ejection is apparently fundamentally linked to the process of active mass accretion onto supermassive black holes. X-rays, generated in the innermost regions surrounding accreting black holes, travel through the nuclear environments to the observer. X-ray studies of