V404 Cygni

On June 15, the Swift satellite caught the onset of a rare X-ray outburst from a stellar-mass black hole in the binary system V404 Cygni. In that system a stream of gas from a star much like the sun flows toward a 10 solar mass black hole. Instead of spiraling into the black hole, the gas accumulates in an accretion disk around it. Every couple of decades, the disk changes state, sending the gas rushing inward. The result is a new X-ray outburst.

[youtube https://www.youtube.com/watch?v=fCWteTkhd_A]

Video Credit: NASA

Swift’s Gamma Ray Burst Number 1,000

grb151027b_uvot_xrt_labeled_2160GRB 151027B, Swift‘s 1,000th burst, is in the center of this composite X-ray, ultraviolet, and optical image. X-rays were captured by Swift‘s X-Ray Telescope within minutes after the Burst Alert Telescope detected the blast. Swift‘s Ultraviolet/Optical Telescope (UVOT) began observations a few seconds later and faintly detected the burst in visible light. The image includes X-rays with energies from 300 to 6,000 eV, mostly from the burst, and lower-energy light seen through the UVOT’s visible, blue and ultraviolet filters (color shifted, respectively, to red, green and blue).

Image Credit: NASA

Rings Around a Black Hole

V404 Cygni Black HoleV404 Cygni is a binary system that contains an erupting black hole. These rings of x-ray light centered on that system were imaged by the x-ray telescope aboard the Swift satellite. Color indicates the energy of the X-rays, with red representing the lowest (800 to 1,500 electron volts, eV), green for medium (1,500 to 2,500 eV), and blue for the most energetic (2,500 to 5,000 eV). Visible light has energies ranging from about 2 to 3 eV. The dark lines running diagonally through the image are artifacts of the imaging system.

Image Credits: Andrew Beardmore (Univ. of Leicester) and NASA

A Decade of Swift

The Swift satellite has been on orbit for ten years. It was the first  project I worked on at Goddard Space Flight Center. I designed and tested the ultra-low-noise power regulator assemblies that run the detector assemblies in the Burst Alert Telescope. I did the circuit design for the variable output high-voltage regulators that provide bias power to the sensors in the BAT detector assemblies. The BAT sensor array is held at a constant temperature (298 K, ± 0.5 K). I designed the pulse-width modulation regulators used in the thermal control system. The same type of PWM is used in the thermal controls for the star trackers which are a part of the satellite’s navigation system. Given that the mission design life was two years, it’s nice to see that my first bits of work are holding up.

Video Credit: NASA