Discovery of Energy-dependent X-Ray Microlensing in Q2237+0305

• Published in: Astrophysical journal. Letters 2011-10, Vol.740 (2), p.L34-jQuery1323915064051='48'
• Main Authors: Chen, Bin, Dai, Xinyu, Kochanek, C. S, Chartas, George, Blackburne, Jeffrey A, Kozłowski, Szymon
• Format: Article
• Language: English
• Subjects: ACCRETION DISKS; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; COSMIC RADIO SOURCES; ELECTROMAGNETIC RADIATION; ELECTRONS; ELEMENTARY PARTICLES; EMISSION; ENERGY DEPENDENCE; FERMIONS; HARD X RADIATION; IONIZING RADIATIONS; LENSES; LEPTONS; MONITORING; QUASARS; RADIATION MONITORING; RADIATIONS; SOFT X RADIATION; TAIL ELECTRONS; X RADIATION
• ISSN: 2041-8205; 2041-8213
• DOI: 10.1088/2041-8205/740/2/L34

We present our long-term Chandra X-ray monitoring data for the gravitationally lensed quasar Q2237+0305 with 20 epochs spanning 10 years. We easily detect microlensing variability between the images in the full (0.2-8 keV), soft (0.2-2 keV), and hard (2-8 keV) bands at very high confidence. We also detect, for the first time, chromatic microlensing differences between the soft and hard X-ray bands. The hard X-ray band is more strongly microlensed than the soft band, suggesting that the corona above the accretion disk thought to generate the X-rays has a non-uniform electron distribution, in which the hotter and more energetic electrons occupy more compact regions surrounding the black holes. Both the hard and soft X-ray bands are more strongly microlensed than the optical (rest-frame UV) emission, indicating that the X-ray emission is more compact than the optical, confirming the microlensing results from other lenses.