Quasi-stars: Cocoons with a Black Hole Inside ⚡ экспресс
Астрофизики создали модели квазизвёзд — гигантских газовых оболочек, раздуваемых излучением аккрецирующей чёрной дыры в центре. Они показали, что при быстром наборе массы (более 0.1 массы Солнца в год) такие объекты становятся конвективными, с температурой поверхности 4000–9000 К, и коллапсируют в чёрную дыру при массе около 35–66 тысяч солнечных. Их свечение совпадает с наблюдаемым у «маленьких красных точек» (LRD) на красных смещениях z<4.5. Любопытно, что свойства квазизвёзд почти не зависят от металличности — эта «космическая кухня» работает на любом сырье. Это объясняет природу загадочных источников света в ранней Вселенной.
The mystery of how black holes grew so fast in the early Universe might be solved by quasi-stars. These are giant gas cocoons with a black hole tucked inside. Matter falling into the hole heats up and blasts out so much light that it prevents the cocoon from collapsing. Such an object weighs thousands of Suns and outshines an entire galaxy.
New simulations reveal: if the black hole gobbles up at least a tenth of a solar mass per year, the whole cocoon churns and glows with a reddish light—exactly like the mysterious 'little red dots' in the distant cosmos. These dots have long puzzled astronomers. Because of the expansion of the Universe, their light is shifted to the red, but what exactly is shining remained unknown. Once the cocoon's mass reaches tens of thousands of solar masses, spacetime curvature triggers an instability, and a black hole is born at the center.
The paradox is that a black hole, typically a light-gobbling monster, becomes the main source of illumination itself. By comparing the observed brightness of the little red dots with models, scientists found that they match the required accretion rate. This is how quasi-stars likely ignited in the young cosmos and, perhaps, became the seeds of supermassive black holes.
🎯 If a quasi-star were placed where the Sun is, its envelope would stretch beyond the orbit of Jupiter, and inside it would hide a black hole the size of a small city.