This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
This image could be re-created using vector graphics as an SVG file. This has several advantages; see Commons:Media for cleanup for more information. If an SVG form of this image is available, please upload it and afterwards replace this template with {{vector version available|new image name}}. It is recommended to name the SVG file “PIA19822-MagneticBlackHoleWaves-AlfvenS-waves-20150709.svg”—then the template Vector version available (or Vva) does not need the new image name parameter.
This image was uploaded in the JPEG format even though it consists of non-photographic data. This information could be stored more efficiently or accurately in the PNG or SVG format. If possible, please upload a PNG or SVG version of this image without compression artifacts, derived from a non-JPEG source (or with existing artifacts removed). After doing so, please tag the JPEG version with {{Superseded|NewImage.ext}} and remove this tag. This tag should not be applied to photographs or scans. If this image is a diagram or other image suitable for vectorisation, please tag this image with {{Convert to SVG}} instead of {{BadJPEG}}. If not suitable for vectorisation, use {{Convert to PNG}}. For more information, see {{BadJPEG}}.
This cartoon shows how magnetic waves, called Alfven S-waves, propagate outward from the base of black hole jets. The jet is a flow of charged particles, called a plasma, which is launched by a black hole. The jet has a helical magnetic field (yellow coil) permeating the plasma. The waves then travel along the jet, in the direction of the plasma flow, but at a velocity determined by both the jet's magnetic properties and the plasma flow speed. The BL Lac jet examined in a new study is several light-years long, and the wave speed is about 98 percent the speed of light.
The copyright holder of this file, NASA/JPL-Caltech, allows anyone to use it for any purpose, provided that the copyright holder is properly attributed. Redistribution, derivative work, commercial use, and all other use is permitted.
According to JPL's image use policy additional restriction is that no endorsement of any product or service by Caltech, JPL or NASA is claimed or implied.
Caltech's disclaimer: Caltech makes no representations or warranties with respect to ownership of copyrights in the images, and does not represent others who may claim to be authors or owners of copyright of any of the images, and makes no warranties as to the quality of the images. Caltech shall not be responsible for any loss or expenses resulting from the use of the images, and you release and hold Caltech harmless from all liability arising from such use.
Usage on the English Wikipedia: On the English Wikipedia you can use the {{JPL Image}} template to display the copyright notice. (See w:Wikipedia:Using JPL images for details)
Captions
Add a one-line explanation of what this file represents