Seminar: Dr. Herman Lee Marshall | MIT
In-Person PHYS 401
Location
Physics : 401
Date & Time
October 16, 2024, 11:00 am – 12:00 pm
Description
TITLE: "Chandra Imaging of Quasar Jets for 25 Years”
ABSTRACT: I will provide a personal history of Chandra imaging of quasar jets. It was perhaps the first surprise finding obtained with Chandra: that quasar jets were commonly bright in X-rays and readily resolved. There was an initial mystery as to why they were so bright encouraging a model where the X-rays result from Compton upscattering of cosmic microwave background (CMB) photons by electrons in bulk relativistic motion — the iC-CMB model. Many studies over the first 10-15 years of Chandra were carried out with this model in mind. These and other studies gradually showed difficulties with the iC-CMB model. After a preponderance of evidence, it appears that this model may only apply to those quasars with the highest redshifts. There are intriguing features that indicate that there is much more to understand. Finally, I would like to introduce the potential for imaging at significantly higher resolution.
ABSTRACT: I will provide a personal history of Chandra imaging of quasar jets. It was perhaps the first surprise finding obtained with Chandra: that quasar jets were commonly bright in X-rays and readily resolved. There was an initial mystery as to why they were so bright encouraging a model where the X-rays result from Compton upscattering of cosmic microwave background (CMB) photons by electrons in bulk relativistic motion — the iC-CMB model. Many studies over the first 10-15 years of Chandra were carried out with this model in mind. These and other studies gradually showed difficulties with the iC-CMB model. After a preponderance of evidence, it appears that this model may only apply to those quasars with the highest redshifts. There are intriguing features that indicate that there is much more to understand. Finally, I would like to introduce the potential for imaging at significantly higher resolution.
