![\"A](\"https:\/\/cdn.sci.news\/images\/enlarge13\/image_14537e-Fermionic-Dark-Matter.jpg\")
<\/a><\/p>\nA compact object made of self-gravitating fermionic dark matter. Image credit: Gemini AI.<\/p>\n
According to the leading theory, Sagittarius A*<\/a> \u2014 a proposed supermassive black hole at the heart of our Galaxy \u2014 is responsible for the observed orbits of a group of stars, known as the S-stars, which whip around at tremendous speeds of up to a few thousand kilometers per second.<\/p>\n Dr. Crespi and co-authors have instead put forward an alternative idea \u2014 that a specific type of dark matter made up of fermions, or light subatomic particles, can create a unique cosmic structure that also fits with what we know about the Milky Way\u2019s core.<\/p>\n It would in theory produce a super-dense, compact core surrounded by a vast, diffuse halo, which together would act as a single, unified entity.<\/p>\n The Milky Way\u2019s inner core would be so compact and massive that it could mimic the gravitational pull of a black hole and explain the orbits of S-stars that have been observed in previous studies, as well as the orbits of the dust-shrouded objects known as G-sources which also exist nearby.<\/p>\n Of particular importance to the new research is the latest data from ESA\u2019s Gaia DR3 mission, which has meticulously mapped the rotation curve of the Milky Way\u2019s outer halo, showing how stars and gas orbit far from the center.<\/p>\n It observed a slowdown of our Galaxy\u2019s rotation curve, known as the Keplerian decline, which can be explained by their dark matter model\u2019s outer halo when combined with the traditional disk and bulge mass components of ordinary matter.<\/p>\n This strengthens the fermionic model by highlighting a key structural difference.<\/p>\n While traditional Cold Dark Matter halos spread out following an extended \u2018power law\u2019 tail, the fermionic model predicts a tighter structure, leading to more compact halo tails.<\/p>\n \u201cThis is the first time a dark matter model has successfully bridged these vastly different scales and various object orbits, including modern rotation curve and central stars data,\u201d said Dr. Carlos Arg\u00fcelles, also from the Institute of Astrophysics La Plata.<\/p>\n \u201cWe are not just replacing the black hole with a dark object; we are proposing that the supermassive central object and the Galaxy\u2019s dark matter halo are two manifestations of the same, continuous substance.\u201d<\/p>\n Crucially, the team\u2019s fermionic dark matter model had already passed a significant test.<\/p>\n