Astronomy:Galactic Center GeV excess

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Short description: Unexplained gamma rays from the galactic center
Gamma-ray radiation (greater than 1 Gev) detected over the entire sky; brighter areas are more radiation (five year study by the Fermi Gamma-ray Space Telescope: 2009–2013)

The Galactic Center GeV Excess (GCE) is an unexpected surplus of gamma-ray radiation in the center of the Milky Way galaxy. This spherical source of radiation was first detected in 2009[1][2] by the Fermi Gamma-ray Space Telescope and is unexplained by direct observation.[3] Two percent of the gamma ray radiation in a 30° radius circle around the galactic center is attributed to the GCE. (As of 2020), this excessive (and diffused) gamma-ray radiation is not well understood by astronomers.[4][5][6][7]

Some astronomers argue that self-annihilating dark matter (which is not otherwise known to radiate) may be the cause of the GCE, while others prefer a population of pulsars (which have not been observed) as the source.[8][3]

Astronomers have suggested that self-annihilating dark matter may be a dominant contributor to the GCE, based on analysis using non-Poissonian template fitting statistical methods,[5] wavelet methods,[7] and studies by other astronomers may support this idea.[9][10] More recently, in August 2020, other astronomers have reported that self-annihilating dark matter may not be the explanation for the GCE after all.[11][12] Other hypotheses include ties to a yet unseen population of millisecond pulsars[13][14] or young pulsars, burst events, the stellar population of the galactic bulge,[15] or the Milky Way's central supermassive black hole.[16]

See also

References

  1. Goodenough, Lisa; Hooper, Dan (2009-11-11). "Possible Evidence For Dark Matter Annihilation In The Inner Milky Way From The Fermi Gamma Ray Space Telescope". arXiv:0910.2998 [hep-ph].
  2. Wolchover, Natalie (2014-03-03). "Case for Dark Matter Signal Strengthens" (in en). https://www.quantamagazine.org/case-for-dark-matter-signal-strengthens-20140303/. 
  3. 3.0 3.1 Cho, Adrian (12 November 2019). "Physicists revive hunt for dark matter in the heart of the Milky Way" (in en). Science | AAAS. https://www.science.org/content/article/physicists-revive-hunt-dark-matter-heart-milky-way. Retrieved 31 March 2020. 
  4. Starr, Michelle (30 April 2019). "Something's Glowing at The Heart of Our Galaxy, But It May Not Be What We Thought". ScienceAlert.com. https://www.sciencealert.com/the-mysterious-glow-at-the-heart-of-the-milky-way-might-be-dark-matter-after-all. Retrieved 30 April 2019. 
  5. 5.0 5.1 Leane, Rebecca K.; Slatyer, Tracy R. (17 April 2019). "Dark Matter Strikes Back at the Galactic Center". Phys. Rev. Lett. 123 (24): 241101. doi:10.1103/PhysRevLett.123.241101. PMID 31922851. 
  6. Fadelli, Ingrid (14 July 2020). "Could recently spotted dim point sources explain the galactic center excess (GCE)?". Phys.org. https://phys.org/news/2020-07-dim-sources-galactic-center-excess.html. Retrieved 14 July 2020. 
  7. 7.0 7.1 Zhong, Yi-Ming; McDermott, Samuel D.; Cholis, Ilias; Fox, Patrick J. (2020). "Testing the Sensitivity of the Galactic Center Excess to the Point Source Mask". Phys. Rev. Lett. 124 (23): 231103. doi:10.1103/PhysRevLett.124.231103. PMID 32603155. Bibcode2020PhRvL.124w1103Z. 
  8. "Is there dark matter at the center of the Milky Way?" (in en). 2019-12-10. https://news.mit.edu/2019/center-milky-way-dark-matter-gce-1211. 
  9. Cuoco, Alessandro (4 March 2019). "Scrutinizing the evidence for dark matter in cosmic-ray antiprotons". Physical Review D 99 (10): 103014. doi:10.1103/PhysRevD.99.103014. Bibcode2019PhRvD..99j3014C. 
  10. Cholis, Ilias et al. (6 March 2019). "A Robust Excess in the Cosmic-Ray Antiproton Spectrum: Implications for Annihilating Dark Matter". Physical Review D 99 (10): 103026. doi:10.1103/PhysRevD.99.103026. Bibcode2019PhRvD..99j3026C. 
  11. Starr, Michelle (28 August 2020). "There's a Strange Glow in The Centre of Our Galaxy, And It's Not What We Thought It Was". ScienceAlert.com. https://www.sciencealert.com/a-strange-glow-in-the-galactic-centre-is-not-the-annihilation-of-dark-matter. Retrieved 28 August 2020. 
  12. Abazajian, Kevork N. (4 August 2020). "Strong constraints on thermal relic dark matter from Fermi-LAT observations of the Galactic Center". Physical Review D 102 (43012): 043012. doi:10.1103/PhysRevD.102.043012. Bibcode2020PhRvD.102d3012A. 
  13. Bartels, Richard et al. (February 2016). "Strong Support for the Millisecond Pulsar Origin of the Galactic Center GeV Excess". Physical Review Letters 116 (5): 051102. doi:10.1103/PhysRevLett.116.051102. PMID 26894696. Bibcode2016PhRvL.116e1102B. 
  14. Gautam, Anuj; Crocker, Roland M.; Ferrario, Lilia; Ruiter, Ashley J.; Ploeg, Harrison; Gordon, Chris; Macias, Oscar (2022-04-28). "Millisecond pulsars from accretion-induced collapse as the origin of the Galactic Centre gamma-ray excess signal" (in en). Nature Astronomy 6 (6): 703–707. doi:10.1038/s41550-022-01658-3. ISSN 2397-3366. Bibcode2022NatAs...6..703G. https://www.nature.com/articles/s41550-022-01658-3. 
  15. Macias, Oscar et al. (12 March 2018). "Galactic bulge preferred over dark matter for the Galactic centre gamma-ray excess". Nature Astronomy 2 (5): 387–392. doi:10.1038/s41550-018-0414-3. Bibcode2018NatAs...2..387M. http://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2018-02026%22. 
  16. Hooper, Dan; Goodenough, Lisa (21 March 2011). "Dark matter annihilation in the Galactic Center as seen by the Fermi Gamma Ray Space Telescope". Physics Letters B 697 (5): 412–428. doi:10.1016/j.physletb.2011.02.029. Bibcode2011PhLB..697..412H. 

Further reading