Dr J (Dr Jasmina) is an astronomer and lecturer at the School of Physics and Astronomy explains the connection between cosmic rays, the most energetic particles in the Universe, and supernova remnants (SNRs). Supernova remnants are very likely responsible for creating lower-energy cosmic rays. Active Galactive Nuclei (ie, massive black holes in the centre of active galaxies) are also linked to cosmic rays with higher energies. Image credits (in order of appearance) and extra info: Cosmic ray shower, artist's impression. Credit: ASPERA network The magnetic field along the Galactic plane. Credit: ESA/Planck Collaboration. Acknowledgment: M.-A. Miville-Deschênes, CNRS – Institut d’Astrophysique Spatiale, Université Paris-XI, Orsay, France http://www.esa.int/spaceinimages/Images/2014/12/The_magnetic_field_along_the_Galactic_plane Supernova 1987A before and after. Credit: Australian Astronomical Observatory http://oldweb.aao.gov.au/images/captions/aat050.html SNR Cassiopeia A. Credit: X-ray: NASA/CXC/SAO; Optical: NASA/STScI; Infrared: NASA/JPL-Caltech/Steward/O.Krause et al. http://chandra.harvard.edu/photo/2005/casa/ Kepler SNR. Credit: NASA https://www.nasa.gov/multimedia/imagegallery/image_feature_219.html SNR N49. Credit: X-ray: (NASA/CXC/Penn State/S.Park et al.); Optical: NASA/STScI/UIUC/Y.H.Chu & R.Williams et al http://chandra.harvard.edu/photo/2010/n49/ SNR E0102-72. Credit: X-ray (NASA/CXC/SAO); optical (NASA/HST); radio: (ACTA) Cygnus loop SNR (Veil nebula) in ultraviolet. Credit: NASA/JPL-Caltech SNR B0509-67.5 Credit: Chandra, NASA, ESA, the Hubble Heritage Team (STScI/AURA), and NASA/CXC/SAO/J. Hughes SN1006 in X-rays. Credit: Koyama et al., Nature, 378, 255, 1995 http://www-cr.scphys.kyoto-u.ac.jp/research/xray/xray-e.html#SN1006 https://heasarc.gsfc.nasa.gov/docs/objects/heapow/archive/nebulae/asca_sn1006.html http://imagine.gsfc.nasa.gov/features/satellites/archive/asca_sn1006.html VERITAS TeV gamma-ray count map of the region around Tycho's SNR, overlaid with X-ray emission from the SNR (black contours) and showing surrounding molecular clouds (magenta lines). Credit: Acciari et al., the Astrophysical Journal 730, L20, 2011 http://veritas.sao.arizona.edu/veritas-science/veritas-results-mainmenu-72/271-could-we-put-in-a-journal-reference-here- How to make a Cloud Chamber (Cosmic Ray Detector) https://www.youtube.com/watch?v=_qbYvZ-Op4M Mars with thicker atmosphere in the past and with the current, thinner atmosphere. Credit: NASA/GSFC http://lasp.colorado.edu/home/wp-content/uploads/2013/04/wetmars_drymars.jpg Mars rover Curiosity. Credit: NASA/JPL-Caltech http://mars.nasa.gov/msl/mission/instruments/radiationdetectors/rad/ http://www.sci-news.com/space/science-mars-radiation-measurements-surface-01629.html What are AGNs? http://imagine.gsfc.nasa.gov/science/objects/active_galaxies2.html