Discovery of a high confidence soft lag from an X-ray flare of Markarian 421

You-Hong Zhang, Zheng-Tian Hou, Li Shao +1

We present the X-ray variability properties of the X-ray and TeV bright blazar Mrk 421 with a ~60 ks long XMM-Newton observation performed on November 9-10, 2005. The source experi…