Astronomy Picture of the Day

   [1]Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                              2021 September 1
       [2]The picture shows the radio jets emitted from distant active
     galaxies. The jets, made of electrons, appear like dancing ghosts.
          Please see the explanation for more detailed information.

              Dancing Ghosts: Curved Jets from Active Galaxies
   Image Credit: [3]Jayanne English & [4]Ray Norris, [5]EMU-ASKAP, [6]DES;
                  Text: [7]Jayanne English ([8]U. Manitoba)

   Explanation: Why would galaxies emit jets that look like ghosts? And
   furthermore, why do they appear to be [9]dancing? The curled and fluffy
   jets from the [10]supermassive black holes at the [11]centers of two
   host [12]galaxies (top center and lower left) are unlike anything seen
   before. They were found by astronomers using the [13]Australian Square
   Kilometer Array Pathfinder (ASKAP) radio telescope when creating maps
   [14]tracing the evolution of galaxies. Images preceding this
   [15]Evolutionary Map of the Universe survey only showed [16]amorphous
   blobs. Eventually, comparisons of relative amounts of [17]energy
   emitted revealed the glowing elongated structures were created by
   [18]electrons streaming [19]around magnetic field lines
   . Overlaying the [20]radio data on an [21]optical view of the sky
   ([22]Dark Energy Survey) confirmed that the [23]electron streams
   originated from the [24]centers of [25]active galaxies. Usually such
   [26]Active Galactic Nuclei (AGN) produce [27]straight jets. A leading
   hypothesis for the geometric origin of these unusually graceful shapes
   involves the flow of [28]large-scale intergalactic [29]winds.

     Astrophysicists: [30]Browse 2,500+ codes in the Astrophysics Source
                                Code Library
                     Tomorrow's picture: Messier's 51st
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    Authors & editors: [42]Robert Nemiroff ([43]MTU) & [44]Jerry Bonnell
                                 ([45]UMCP)
          NASA Official: Phillip Newman [46]Specific rights apply.
              [47]NASA Web Privacy Policy and Important Notices
                A service of: [48]ASD at [49]NASA / [50]GSFC
                           & [51]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2109/DancingGhosts_EnglishNorris_2524.jpg
   3. https://www.iau.org/administration/membership/individual/8424/
   4. https://www.atnf.csiro.au/people/Ray.Norris/index.html
   5. http://emu-survey.org/
   6. https://www.darkenergysurvey.org/
   7. http://www2.physics.umanitoba.ca/u/english/
   8. https://sci.umanitoba.ca/physics-astronomy/
   9. https://apod.nasa.gov/apod/ap200614.html
  10. https://en.wikipedia.org/wiki/Supermassive_black_hole
  11. https://arxiv.org/abs/2108.00569
  12. https://apod.nasa.gov/apod/image/2109/GhostFiguresPaperNorrisEtAl.pdf
  13. https://www.atnf.csiro.au/projects/askap/index.html
  14. https://www.westernsydney.edu.au/newscentre/news_centre/more_news_stories/dancing_ghosts_point_to_new_discoveries_in_the_cosmos
  15. http://emu-survey.org/
  16. https://i0.wp.com/thecreativecat.net/wp-content/uploads/2013/01/013013-Wordless-TheBlob1.jpg?resize=800,594
  17. https://heasarc.gsfc.nasa.gov/docs/xte/learning_center/xray_techc.html
  18. https://heasarc.gsfc.nasa.gov/docs/xte/learning_center/xray_techc.html
  19. https://ase.tufts.edu/cosmos/view_picture.asp?id=1424
  20. https://science.nasa.gov/ems/05_radiowaves
  21. https://science.nasa.gov/ems/09_visiblelight
  22. https://www.darkenergysurvey.org/
  23. https://pwg.gsfc.nasa.gov/Education/whelect.html
  24. https://apod.nasa.gov/apod/ap210804.html
  25. https://imagine.gsfc.nasa.gov/science/objects/active_galaxies1.html
  26. https://en.wikipedia.org/wiki/Active_galactic_nucleus
  27. https://apod.nasa.gov/apod/ap121205.html
  28. https://apod.nasa.gov/apod/ap200223.html
  29. https://apod.nasa.gov/apod/ap210623.html
  30. http://ascl.net/
  31. https://apod.nasa.gov/apod/ap210831.html
  32. https://apod.nasa.gov/apod/archivepix.html
  33. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  34. https://apod.nasa.gov/apod/lib/aptree.html
  35. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  36. https://apod.nasa.gov/apod/calendar/allyears.html
  37. https://apod.nasa.gov/apod.rss
  38. https://apod.nasa.gov/apod/lib/edlinks.html
  39. https://apod.nasa.gov/apod/lib/about_apod.html
  40. http://asterisk.apod.com/discuss_apod.php?date=210901
  41. https://apod.nasa.gov/apod/ap210902.html
  42. http://www.phy.mtu.edu/faculty/Nemiroff.html
  43. http://www.phy.mtu.edu/
  44. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  45. http://www.astro.umd.edu/
  46. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  47. https://www.nasa.gov/about/highlights/HP_Privacy.html
  48. https://astrophysics.gsfc.nasa.gov/
  49. https://www.nasa.gov/
  50. https://www.nasa.gov/centers/goddard/
  51. http://www.mtu.edu/