1. Department of Astronomy & Astrophysics, The Pennsylvania State University, University Park, PA 16802, USA
2. Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802, USA
3. Department of Physics, 104 Davey Lab, The Pennsylvania State University, University Park, PA 16802, USA
4. Department of Astronomy, Xiamen University, Xiamen, Fujian 361005, China
5. Huntingdon Institute for X-ray Astronomy, LLC, 10677 Franks Road, Huntingdon, PA 16652, USA
6. Department of Chemistry and Physical Sciences, The College of St. Scholastica, Duluth, MN 55811, USA