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The mysterious birth of direct-explosion black holes: Why do these super-massive black holes shock astronomical scientists?
In the early history of the universe, scientists noticed some special objects. The way these objects were born marked a major category in the evolution of matter in the universe: direct explosion black holes (DCBHs). These mysterious black holes were created about 100 to 250 million years ago, a period known as redshift z between about 15 and 30.
The formation process of direct explosion black holes is different from black holes in traditional theories. These black holes are formed through direct gravitational collapse rather than evolving from the death of stars.
The formation of a direct explosion black hole requires specific environmental conditions. The main conditions include; a gas with zero metallic content (containing only hydrogen and helium), irradiation of Lyman–Werner photons high enough to excite hydrogen atoms, and a laser stream capable of destroying hydrogen molecules. These conditions prevent the gas from cooling and fragmenting, allowing the gas cloud to undergo gravitational collapse intact and reach extremely high matter densities.
When the density of matter reaches about 107 g/cm³, these gas clouds will undergo ordinary relativistic instability and turn into direct explosion black holes. This means they were born directly from primordial gas clouds, rather than from stellar progenitors.
According to a computer simulation reported in July 2022, researchers found that under rare conditions, strong and cold accretion flows can create massive black holes without ultraviolet radiation and supersonic flow. seed. This simulation shows that in an environment that grew to about 40 million solar masses, several supergiants were eventually formed and successfully transformed into direct explosion black holes.
The rarity of direct black hole explosions
Directly explosive black holes are considered to be extremely rare objects in the high-redshift universe. Current cosmological simulations show that the number of these black holes at redshift 15 may be only about 1 per cubic gigaparsec. This prediction is strongly influenced by the Lyman–Werner photon minimum flux, and under some of the most optimistic scenarios, the density of DCBHs could be as high as 107 cells per cubic gigasecond.
The discovery of direct explosion black holes
In 2016, a team of researchers led by Harvard University astrophysicist Fabio Pacucci used data from the Hubble Space Telescope and the Chandra X-ray Observatory to identify two candidates for direct explosion of black holes for the first time. These candidates are all located in the redshift region of z>6, and their spectral characteristics in the CANDELS GOODS-S field are consistent with predictions.
These directly exploding black holes are predicted to produce more significant infrared radiation than other high-redshift sources, and further observations, particularly with the James Webb Space Telescope, will be critical to confirm the nature of these sources.
Differences from other black holes
Different from the formation process of primordial black holes, which are related to the direct collapse of energy and charged matter, the formation of direct-explosion black holes results from the collapse of unusually dense and large gas regions. It is worth noting that black holes formed by third-generation stars (ie, Population III stars) do not belong to the category of direct explosion black holes.
Summary
The discovery of direct explosion black holes not only expands our understanding of the formation of black holes, but also reveals the complex phenomena that may exist in the early universe. These mysterious objects are redefining our fundamental understanding of the evolution of the universe. With the advancement of technology, will we be able to uncover more secrets of these black holes in the future?
