Blazars, Quasars, and Swift

Swift was the first satellite I worked on at Goddard Space Flight Center. I designed the thermal controller used to regulate the temperature of the detector array in the Burst Alert Telescope, the bias power regulators for the detectors, and the ultra-quiet power supplies for the detector electronics. Here’s some of the science done with the Burst Alert Telescope.

Video Credit: NASA

The Case of the Runaway Quasar

This Hubble image is an unusual sight—a runaway quasar fleeing from its galaxy’s central hub. A quasar is the visible, energetic signature of a black hole, The black hole cannot be seen directly, but it’s the energy source at the heart of its quasars. The quasar, in turn, is an intense, compact source of radiation that can outshine an entire galaxy.

The green dotted line marks the visible boundary of the galaxy. The quasar, called 3C 186, appears as if it were a bright star just off-center, and it’s moving rapidly away from the galactic center. The force involved is roughly equivalent to the energy of 100 million supernovas exploding simultaneously. One plausible explanation for this propulsive energy is that the quasar is being pushed by gravitational waves unleashed by the merger of two other black holes at the center of the galaxy.

Image Credit: NASA / ESA / STScI

Black Hole Feedback

The evolution of a galaxy is related to the growth of the supermassive black hole at its center. During the galaxy’s quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. This animation illustrates how black-hole feedback works during that phase. Dense gas and dust in the center simultaneously powers the black hole and hides it from view. The black hole’s radiation wind drives huge outflows of cold gas causing a shock wave that clears gas and dust from the central galaxy.


Video Credit: NASA