Telesikopu ya Fermi inayang'anitsitsa bwino za kutuluka kwa γ-ray pakatikati pa mlalang'amba wathu wapanyumba womwe umawoneka wosazungulira komanso wophwanyika. Otchedwa Galactic Center Excess (GCE), owonjezerawa γ-ray ndi chizindikiro chotheka cha zinthu zakuda zomwe zimatuluka ngati chotulukapo cha kudziwononga tokha kwa tinthu tating'onoting'ono tating'onoting'ono (WIMPs), woyimira tinthu tamdima. Komabe, kuchulukira kwa γ-ray komwe kumawonedwa pakatikati pa mlalang'amba kungakhalenso chifukwa cha ma millisecond pulsars (MSPs). Mpaka pano, zinkaganiziridwa kuti morphology ya GCE chifukwa cha zinthu zakuda (DM) idzakhala yozungulira. Kafukufuku woyerekeza waposachedwa akuwonetsa kuti gamma-ray morphology chifukwa cha DM ikhoza kukhala yosazungulira komanso yosalala. Izi zikutanthauza kuti kuwonongedwa kwa zinthu zakuda (DM) ndi millisecond pulsars (MSPs) zongoyerekeza za GCE yowonedwa ndizotheka chimodzimodzi. Ma cheza a gamma opangidwa powononga zinthu zakuda (DM) atha kukhala ndi mphamvu yayikulu kwambiri pafupifupi 0.1 tera-electron-volts (TeV). Ma telescope amtundu wa gamma-ray sangathe kuzindikira mwachindunji ma photon amphamvu kwambiri amenewa. Chifukwa chake, kutsimikizira kwa mtundu wakuda (DM) wa Galactic Center Excess (GCE) kutheka mukamaliza maphunziro ndi malo owonera ma tera γ-ray monga Cherenkov Telescope Array Observatory (CTAO) ndi Southern Wide-field Gamma-ray Observatory (SWGO).
Nkhani ya zinthu zakuda inayamba mu 1933 pamene Fritz Zwicky anaona kuti milalang'amba yothamanga kwambiri mu Coma Cluster singakhoze kugwirizanitsa pamodzi ndi kukhalabe okhazikika popanda kukhalapo kwa zinthu zina zomwe ziri zosaoneka koma zokhala ndi mphamvu yokoka yokwanira kuletsa milalang'amba kuti isagwe. Iye anayambitsa mawu akuti “mdima” kutanthauza zinthu zosaoneka zimenezo. M'zaka za m'ma 1960, Vera Rubin adathandizira kumvetsetsa kwathu zakuda. Ananenanso kuti nyenyezi zomwe zili m'mphepete mwa Andromeda ndi milalang'amba ina zimazungulira mwachangu monga momwe nyenyezi zimathamangira pakati. Pa kuchuluka kwa zinthu zonse zowonedwa, mlalang'ambawo uyenera kuwulukira padera, zomwe zimachititsa kuti pakhale zinthu zina zosaoneka zomwe zimasunga milalang'ambayo pamodzi ndi kuipangitsa kuzungulira liŵiro lalikulu. Kuyeza kwake kwa mapindikidwe ozungulira a mlalang'amba wa Andromeda kunapereka umboni wakale kwambiri wa zinthu zakuda.
Tsopano tikudziwa kuti zinthu zakuda sizigwirizana ndi kuwala kapena mphamvu yamagetsi. Simayamwa, kuwunikira kapena kutulutsa kuwala kapena ma radiation ena aliwonse amagetsi ndipo ndi yosaoneka chifukwa chake imatchedwa mdima. Koma zimawunjikana mwa mphamvu yokoka ndipo zimakhala ndi mphamvu yokoka pa zinthu wamba, ndipo umu ndi momwe kupezeka kwake mumlengalenga kumaganiziridwa. Milalang'amba imagwiridwa pamodzi mogwirizana ndi mphamvu yokoka ya zinthu zamdima zomwe zimapanga 26.8% ya mphamvu zazikulu za chilengedwe chonse pamene chilengedwe chonse chowoneka kuphatikizapo zinthu zonse za baryonic zomwe tonsefe timapangidwa nazo zimapanga 4.9% yokha ya chilengedwe chonse. 68.3% yotsala ya mphamvu zazikulu za chilengedwe chonse ndi mphamvu yakuda.
Sizikudziwika kuti nkhani yamdima ndi chiyani. Palibe particles zofunika mu Model Standard ali ndi zinthu zofunika kuti zikhale zakuda. Mwinamwake, zongopeka za "supersymmetric particles" zomwe zimagwirizanitsa ndi tinthu tating'ono ta mu Standard Model zimapanga zinthu zakuda. Mwinamwake pali dziko lofanana la zinthu zamdima. WIMPs (Weakly Interacting Massive Particles), ma axion, kapena sterile neutrinos ndi tinthu tating'onoting'ono topitilira Standard Model yomwe imatsogolera ofuna kusankha. Komabe, palibe chipambano chomwe chapindula pozindikira tinthu totere.
Pali ma projekiti angapo (monga Kuyesa kwa XENON, Ntchito ya DarkSide-20k, EURECA Rxperiment, ndi RES-NOVA) pakali pano kuti azindikire mwachindunji tinthu tating'onoting'ono tamdima. Izi nthawi zambiri zimakhala zowunikira mpweya wabwino wamadzimadzi kapena zowunikira za cryogenic zomwe zidapangidwa kuti zizitha kuzindikira ma siginecha ang'onoang'ono pakulumikizana kwa tinthu takuda. Komabe, ngakhale pali njira zambiri zatsopano, palibe projekiti yomwe yatha kuzindikira mwachindunji tinthu tamdima.
Kuti mupeze umboni wosalunjika wa chinthu chamdima, wina atha kuyang'ana mphamvu yokoka ya zinthu zamdima, monga Fritz Zwicky ndi Vera Rubin adapeza zinthu zakuda powerenga momwe milalang'amba imagwirira ntchito limodzi ngakhale kuti ili ndi liwiro lokwera kwambiri pa chinthu wamba. Mphamvu yokoka ya magalasi (kupindika kwa kuwala) ndi zotsatira za kayendedwe ka nyenyezi mumlengalenga zingaperekenso umboni wosalunjika wa kukhalapo kwa zinthu zakuda. Kuonjezera apo, zinthu zowononga (monga gamma-ray, neutrinos, ndi cosmic ray) zomwe zimapangidwa pamene tinthu takuda tating'onoting'ono tawombana mumlengalenga tingasonyezenso kukhalapo kwa zinthu zakuda. Malo amodzi oterowo amene zinthu zakuda zinanenedweratu potengera zinthu zomwe zinawononga tinthu tating'onoting'ono tating'onoting'ono ndi pakatikati pa mlalang'amba wathu wa Milky Way.
Kuzindikira zinthu zakuda pakatikati pa mlalang'amba wathu wa Milky Way
Panali zisonyezo za kuwala kwapakati pa microwave pakati pa Milky Way (MW). Kuwala kopitilira muyeso kunanenedwa kukhala chifukwa cha kutulutsa kwa ma synchrotron kuchokera ku ma elekitironi ogwirizana ndi ma positrons opangidwa mu kuwononga zinthu zakuda za WIMP, motero chizindikiro chotalikirapo cha γ-ray mumtundu wamagetsi mpaka mazana angapo a GeV adanenedweratu. Pambuyo pake, Fermi-Large Area Telescope (LAT) inapeza chizindikiro cha γ-ray chomwe chinadziwika kuti Galactic Center Excess (GCE). Posakhalitsa, zinadziwika kuti Galactic Center Excess (GCE) ingakhalenso chifukwa cha nyenyezi zakale za neutron (millisecond pulsars). Zinkaganiziridwa kuti morphology ya GCE ikanakhala yofunikira - GCE yozungulira yozungulira yozungulira idzakhala chizindikiro cha kutuluka kwa γ-ray kuchokera ku chiwonongeko cha tinthu tamdima (DM) pamene morphology yophwanyika ya GCE ingakhale yosonyeza kuti γ-ray emission kuchokera ku millisecond pulsars (MSP).
Kuyang'ana kwakukulu kwa malo a mlalang'amba wa Milky Way ndi Fermi-Large Area Telescope (LAT) kunawonetsa mlengalenga wosalala. Nthawi zambiri, wina angaphatikizepo kuwoneka kwa nyenyezi zakale (MSP) komabe kafukufuku waposachedwa wofalitsidwa pa 16 Okutobala 2025 watsimikiza kuti ma GCE morphologies omwe adanenedweratu ndi nyenyezi zonse zakale (MSP) ndi mitundu ya kuwonongedwa kwa zinthu zakuda (DM) sizidziwika.
Kuti aphunzire kagawidwe ka zinthu zamdima, ofufuzawo adachita fanizo la morphology ya MW (Milky Way) -ngati milalang'amba. Iwo adapeza kuti ma halos amdima ozungulira milalang'amba komanso kuzungulira madera apakati a milalang'ambayo sanali ozungulira monga momwe amaganizira mu anisotropic model. M'malo mwake, kuwunikaku kunawonetsa kupendekeka kwa zinthu zakuda kwa milalang'amba yonse. Kugawa kwamdima wakuda (DM) wosagwirizana ndi axisymmetric kudawonetsedwanso ndi kuphatikiza mbiri ya mlalang'amba wa Milky Way m'zaka mabiliyoni atatu oyamba m'mbiri ya chilengedwe. Maonekedwe amtundu wa GCE amaphwanyidwa m'chigawo chapakati, chomwe chimaganiziridwa kuti ndi chikhalidwe cha kugawa kwa nyenyezi zakale (MSP). Kafukufuku watsopano wasonyeza kuti nkhani yamdima (DM) imapanga kugawa kwa bokosi komweko. Chifukwa chake, ziwonongeko zonse zakuda (DM) ndi millisecond pulsars (MSPs) zolingalira za GCE yowonedwa ndizotheka chimodzimodzi.
Kaya GCE yowonedwa ndi chifukwa cha zinthu zakuda (DM) kapena chifukwa cha millisecond pulsars (MSPs) zitha kudziwika pomwe malo owonera ma γ-ray monga Cherenkov Telescope Array Observatory (CTAO) ndi Southern Wide-field Gamma-ray Observatory (SWGO) amaliza maphunziro awo a tera-gamma ray m'tsogolomu. Ma cheza a gamma opangidwa ngati chinthu chowononga zinthu zakuda (DM) mkatikati mwa galactic atha kukhala ma photon amphamvu kwambiri okhala ndi mphamvu yayikulu kwambiri pafupifupi 0.1 tera-electron-volts (TeV). Ma telescope amtundu wa gamma-ray sangathe kuzindikira mwachindunji zithunzi zamphamvu kwambirizi. Kuwunikira kwa tera-gamma kudzakhala chandamale chofunikira pazowunikira zamtsogolo za γ-ray monga CTAO ndi SWGO.
Kafukufukuyu ndi sitepe yopita patsogolo pakuzindikira zinthu zakuda mumlengalenga kudzera muzowonongera zake koma kupezeka kwa zinthu zamdima pakatikati pa galactic kungafune kutsimikiziridwa ndi ma Ultra-high mphamvu γ-ray zowonera monga CTAO kapena SWGO mtsogolo. Kupita patsogolo kofunikira kwambiri mu sayansi ya zinthu zakuda kungakhale kuzindikirika mwachindunji kwa tinthu tating'ono ta DM.
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Zothandizira:
- Hochberg, Y., Kahn, YF, Leane, RK et al. Njira zatsopano zodziwira zinthu zakuda. Nat Rev Phys 4, 637–641 (2022). https://doi.org/10.1038/s42254-022-00509-4
- Misiaszeka M. ndi Rossib N. 2024. Kuzindikira kwachindunji kwa zinthu zamdima: kuwunika kofunikira. Symmetry 2024, 16(2), 201; DOI: https://doi.org/10.3390/sym16020201
- Instituto de Física Corpuscular. Kufunafuna zinthu zakuda: njira yatsopano yodziwira zosaoneka. 22 August 2025. Ipezeka pa https://webific.ific.uv.es/web/en/content/search-dark-matter-new-approach-detecting-invisible
- Muru MM, et al 2025. Fermi-LAT Galactic Center Excess Morphology of Dark Matter in Simulations of the Milky Way Galaxy. Makalata Obwereza Mwakuthupi. 135, 161005. Lofalitsidwa 16 October 2025. DOI: https://doi.org/10.1103/g9qz-h8wd . Preprint version ku arXiv. Inatumizidwa 8 Ogasiti 2025. DOI: https://doi.org/10.48550/arXiv.2508.06314
- Johns Hopkins University. Nkhani - Kuwala modabwitsa mu milky way kungakhale umboni wa zinthu zakuda. Yolembedwa pa 16 October 2025. Ipezeka pa https://hub.jhu.edu/2025/10/16/mysterious-glow-in-milky-way-dark-matter/
- Leibniz Institute for Astrophysics. Nkhani - Milky Way imawonetsa kuchuluka kwa gamma ray chifukwa cha kuwonongedwa kwa zinthu zakuda. Yolembedwa pa Okutobala 17, 2025. Ipezeka pa https://www.aip.de/en/news/milkyway-gammaray-darkmatter-annihilation/
- Fermi Gamma-ray Space Telescope. Likupezeka pa https://science.nasa.gov/mission/fermi/
- Cherenkov Telescope Array Observatory (CTAO). Likupezeka pa https://www.ctao.org/emission-to-discovery/science/
- Southern Wide-field Gamma-ray Observatory (SWGO). Likupezeka pa https://www.swgo.org/SWGOWiki/doku.php?id=swgo_rel_pub
- Tartu Observatory. Mbali yamdima ya Universe. Likupezeka pa https://kosmos.ut.ee/en/dark-side-of-the-universe
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, this excess γ-ray is a possible signature of dark matter arising as a product of self-annihilations of weakly interacting massive particles (WIMPs), a dark matter particle candidate. However, the excess γ-ray observed at the galactic centre may also be due to old millisecond pulsars (MSPs). Hitherto, it was held that the morphology GCE due to dark matter (DM) would be spherical. A recent simulation study reveals that gamma-ray morphology due to DM could be significantly nonspherical and flattened. This means both dark matter (DM) annihilations and millisecond pulsars (MSPs) hypotheses for the observed GCE are equally possible. The gamma rays produced in the annihilation of dark matter (DM) would have an extremely high energy level of approximately 0.1 tera-electron-volts (TeV). The standard gamma-ray telescopes cannot detect these high-energy photons directly. Hence, confirmation of dark matter (DM) model of Galactic Centre Excess (GCE) would be possible upon completion of studies by the tera γ-ray observatories like CTAO and SWGO.){kind=link}