Along with collaborators at STScI, UMBC, and FIT, we have put together images of a jet from a black hole, taken by Hubble and spanning 20 years in time. Amazingly, we see that components in the jet appear to catch up to and collide with slower-moving ones, all of them moving at (apparent) faster-than-light speeds!
The whole press release is here: http://hubblesite.org/newscenter/archive/releases/2015/19/
I also recently gave a 15-minute talk on this result and others at the Hubble 25th Anniversary Symposium in April. That talk is here:
The Nature article (published May 28, 2015) is available here:
You can find the latest write-up of my very recent work on the X-ray emission mechanism in kilo-parsec scale quasar jets here: Proceedings of Science, from the Integral Meeting late last year. This work is to be shortly submitted to the Astrophysical Journal.
Along with Markos Georganopoulos, Jeremy Perkins and Justin Finke, we are very happy to announce that the Mid-Atlantic Radio-Loud AGN Meeting will take place on October 10th, 2014 at Goddard Space Flight Center. Everyone in driving distance (or farther!) of Baltimore/DC is welcome to come to this “local” meeting of RL AGN researchers. If you would like to give a talk the registration deadline is September 1st.
One of the major problems in astronomy today is understanding how galaxies first formed and evolved through cosmic time to produce the Universe as we see it today. We now know that most, probably all, massive galaxies have a super-massive black hole at their centers. As an observational astronomer, I am interested in the general question of how the phenomena related to the growth of these black holes affect their wider environment. In particular, I am working to understand the physics and impact of the relativistic jets associated with the most massive black holes, which almost certainly have a major effect on their host galaxies and clusters throughout their lifetimes. At present, my work is concentrated on two fronts – analyzing the kinematics of nearby jets imaged by HST over the past two decades, and using multiwavelength (radio through gamma-ray) data to determine the emission mechanism in powerful quasar jets, a question which has huge implications for our accounting of the radiative output of these jets at TeV energies. TeV emission from jets has been suggested as a means of solving the ‘missing dwarf galaxy problem’ and may point to jets being a significant contributor to reionization.
Results on the optical jet in the nearby source M87 were published in The Astrophysical Journal Letters in 2013. See below a video from the August 2013 Press Release: