Dark Stars: First Light from Invisible Matter ⚡ экспресс
Dark matter annihilation can power the first stars—long-lived dark stars reaching masses M ≳ 10⁵ M⊙ and collapsing into massive black holes, which could serve as seeds for the supermassive black holes observed at high redshifts. A calculation of the diffuse electromagnetic radiation from a cosmological population of such supermassive dark stars and their remnants was performed, accounting for thermal surface emission, annihilation in adiabatically compressed halos, and delayed emission from dark matter clumps around the formed black holes. After considering photon absorption, it is shown that the contribution from dark stars can exceed the extragalactic gamma-ray background recorded by the Fermi-LAT telescope for thermal relic annihilation cross-sections and dark matter masses below ~1 TeV. These are the first population-level multi-messenger constraints on supermassive dark stars as progenitors of early black holes; the diffuse photon and neutrino background provides a powerful complementary avenue to study the role of dark matter in the formation of the first massive structures.
After the Big Bang, the universe was hot and dense. In clumps of dark matter—invisible stuff felt only through gravity—its particles, colliding, annihilated, giving birth to powerful radiation. This hidden heat, like an invisible furnace, warmed gas clouds from within. Colossal dark stars flared up—puffy, sprawling, shining brighter than entire galaxies. When the inner flame died, the star collapsed into a black hole. This mechanism, as Vera Rubin and Fritz Zwicky believed, could have spawned the supermassive holes at the centers of galaxies. Now astrophysicists have modeled the collective light from these giants over the entire history of the universe's expansion. It turns out its faint gamma glow, collected by the Fermi satellite, can be teased out from the background—if the dark matter particles aren't too heavy. This offers a chance to feel out the invisible. And here's an unexpected twist: if such a star were nearby, we'd see it in an ordinary telescope—a bright dot with a bizarre color pattern.
🎯 In an amateur telescope, a dark star would look like a bright dot with an unnatural rainbow hue—like a shard of the early Universe.