Blueshifted absorption lines from X-ray reflection in IRAS 13224-3809

Understand

We explore a disc origin for the highly-blueshifted, variable absorption lines seen in the X-ray spectrum of the Narrow Line Seyfert 1 galaxy IRAS13224-3809.

• The blueshift corresponds to a velocity of about 0.25c.
• Such features in other Active Galactic Nuclei are often interpreted as UltraFast Outflows (UFOs).
• The velocity is of course present in the orbital motions of the inner disk.