Related Experiment Video
Updated: Aug 11, 2026

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow
Published on: February 27, 2016
Direct Measurement of the Jet Geometry in Seyfert Galaxies
Abstract:
We demonstrate that by combining optical, radio, and X-ray observations of a Seyfert galaxy, it is possible to provide a direct measurement of the angle beta between the direction of the radio jet and the normal to the plane of the spiral host galaxy. To do so, we make the assumptions that the inner radio jet is perpendicular to the X-ray observed inner accretion disk and that the observed jet (or the stronger component, if the jet is two-sided) is physically closer to Earth than the plane of the galaxy. We draw attention to the possibility that the measurement will produce a result that is not self-consistent, in which case, for that galaxy, one of the assumptions must fail.
Related Concept Videos
Detection of Black Holes
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Gauss's Law: Spherical Symmetry
Gauss's Law: Cylindrical Symmetry
Gauss's Law: Planar Symmetry
Gravitation Between Spherically Symmetric Masses
Sight Distance in a Vertical Curve

