Hubble Space Telescope image of galaxy NGC 1275. The thread-like extending structures are thought to be composed of gas and suspended in magnetic field. The image was copied from http://www.spacetelescope.org/images/heic0817a/ (accessed 10 May 2013).
galaxy_ngc_1275_heic0817a.jpg
You can use this image freely, without any restrictions, because it was released into Public Domain.
However, it would be nice if the following credits are given:
NASA, ESA and Andy Fabian, license: PD,