Galactic Center GeV excess explained
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., 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]
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, wavelet methods, 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]
Further reading
- The Fermi Galactic Center GeV Excess and Implications for Dark Matter . . M. . Ackermann . etal . 840 . 1 . 43 . May 2017 . 10.3847/1538-4357/aa6cab . 2017ApJ...840...43A . 1704.03910. 119481146 . free .
- Interpretations of galactic center gamma-ray excess confronting the PandaX-II constraints on dark matter-neutron spin-dependent scatterings in the NMSSM . . Liangliang . Shang . Yangle . He . Jingwei . Lian . Yusi . Pan . 1 . 78 . 5 . 390 . May 2018 . 10.1140/epjc/s10052-018-5827-8 . 2018EPJC...78..390S. 1804.08797 . 55864561 .
Notes and References
- 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. hep-ph. 0910.2998.
- Web site: Wolchover. Natalie. 2014-03-03. Case for Dark Matter Signal Strengthens. 2021-08-12. Quanta Magazine. en.
- News: Cho . Adrian . Physicists revive hunt for dark matter in the heart of the Milky Way . 31 March 2020 . Science AAAS . 12 November 2019 . en.
- News: Starr . Michelle . Something's Glowing at The Heart of Our Galaxy, But It May Not Be What We Thought . ScienceAlert.com . 30 April 2019 . 30 April 2019.
- Leane . Rebecca K. . Slatyer . Tracy R. . amp . Dark Matter Strikes Back at the Galactic Center . Phys. Rev. Lett. . 1904.08430 . 17 April 2019. 123 . 24 . 241101 . 10.1103/PhysRevLett.123.241101 . 31922851 . 210150636 .
- News: Fadelli . Ingrid . Could recently spotted dim point sources explain the galactic center excess (GCE)? . Phys.org . 14 July 2020 . 14 July 2020.
- Zhong . Yi-Ming . McDermott . Samuel D. . Cholis . Ilias . Fox . Patrick J. . amp. Testing the Sensitivity of the Galactic Center Excess to the Point Source Mask . Phys. Rev. Lett. . 124 . 23 . 231103 . 1911.12369 . 2020. 10.1103/PhysRevLett.124.231103 . 32603155 . 2020PhRvL.124w1103Z . 208512856 .
- Web site: 2019-12-10 . Is there dark matter at the center of the Milky Way? . 2023-05-04 . MIT News . en.
- Cuoco . Alessandro . etal . Scrutinizing the evidence for dark matter in cosmic-ray antiprotons . Physical Review D . 99 . 10 . 103014 . 1903.01472 . 4 March 2019. 10.1103/PhysRevD.99.103014 . 2019PhRvD..99j3014C . 119333152 .
- Cholis . Ilias . Linden . Tim . Hooper . Dan . 1 . A Robust Excess in the Cosmic-Ray Antiproton Spectrum: Implications for Annihilating Dark Matter . Physical Review D . 99 . 10 . 103026 . 1903.02549 . 6 March 2019. 10.1103/PhysRevD.99.103026 . 2019PhRvD..99j3026C . 118857451 .
- News: Starr . Michelle . There's a Strange Glow in The Centre of Our Galaxy, And It's Not What We Thought It Was . 28 August 2020 . ScienceAlert.com . 28 August 2020 .
- Abazajian, Kevork N. . et al . Strong constraints on thermal relic dark matter from Fermi-LAT observations of the Galactic Center . . 102 . 43012 . 10.1103/PhysRevD.102.043012 . 4 August 2020 . 043012 . 2003.10416 . 2020PhRvD.102d3012A . free .
- Strong Support for the Millisecond Pulsar Origin of the Galactic Center GeV Excess . . Richard . Bartels . Suraj . Krishnamurthy . Christoph . Weniger . 1 . 116 . 5 . 051102 . February 2016 . 10.1103/PhysRevLett.116.051102 . 26894696 . 2016PhRvL.116e1102B . 1506.05104. 217518922 .
- 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 . Nature Astronomy . 6 . 6 . en . 703–707 . 10.1038/s41550-022-01658-3 . 2106.00222 . 2022NatAs...6..703G . 235265843 . 2397-3366.
- Galactic bulge preferred over dark matter for the Galactic centre gamma-ray excess . . Oscar . Macias . Chris . Gordon . Roland M. . Crocker . Brendan . Coleman . Dylan . Paterson . Shunsaku . Horiuchi . Martin . Pohl . 1 . 2 . 5 . 387–392 . 12 March 2018 . 10.1038/s41550-018-0414-3 . 2018NatAs...2..387M. 1611.06644 . 54936254 .
- Hooper . Dan . Goodenough . Lisa . amp . Dark matter annihilation in the Galactic Center as seen by the Fermi Gamma Ray Space Telescope . . 697 . 5 . 412–428 . 21 March 2011 . 10.1016/j.physletb.2011.02.029. 1010.2752 . 2011PhLB..697..412H . 118446838 .