A new theory explains the mysterious expansion of the universe and why it started accelerating soon after the big bang.
Utilizing data from NASA’s James Webb Space Telescope, scientists have unveiled the earliest starlight spectra, revealing low-mass galaxies’ central role in the universe’s dawn. Credit: SciTechDaily.com.
Groundbreaking JWST observations reveal the pivotal role of low-mass galaxies in the early universe’s reionization, challenging existing cosmic evolution theories.
Scientists working with data from NASA’s James Webb Space Telescope (JWST) have obtained the first full spectra of some of the earliest starlight in the universe. The images provide the clearest picture yet of very low-mass, newborn galaxies, created less than a billion years after the Big Bang, and suggest the tiny galaxies are central to the cosmic origin story.
Research reveals the quasar H1821+643, despite its intense activity, has a minimal effect on its host galaxy, overturning expectations about the role of quasars. Astronomers have found a rapidly growing supermassive black hole (quasar) not achieving what they expect from it.
Gauging whether or not we dwell inside someone else’s computer may come down to advanced AI research—or measurements at the frontiers of cosmology.
The team of scientists set about investigating this by analyzing 59 early B-type blue supergiants located in the Large Magellanic Cloud, a satellite galaxy of the Milky Way, and creating novel stellar simulations.
“We simulated the mergers of evolved giant stars with their smaller stellar companions over a wide range of parameters, taking into account the interaction and mixing of the two stars during the merger,” study leader and IAC researcher Athira Menon said in a statement. “The newly born stars live as blue supergiants throughout the second-longest phase of a star’s life, when it burns helium in its core.”
The team’s findings suggest that blue supergiants slip into an evolutionary gap in conventional stellar physics — a phase of stellar evolution where astronomers would not expect to see stars. The question is, Can this explain the remarkable properties of blue supergiant stars? It seems the answer is yes.
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It’s been found in a quasar, which is somewhat terrifyingly known as a ‘feeding black hole’
Black holes are renowned and frightening phenomena—areas characterized by infinite gravitational force, rendering escape impossible. The process of forming a black hole is relatively uncomplicated: it involves compressing a sufficient amount of mass below a specific size threshold. Once this threshold is surpassed, gravity prevails over all other forces, resulting in the creation of a black hole.
The critical threshold varies depending on the quantity of mass being condensed. For an average human, this threshold is comparable to the size of an atomic nucleus. Conversely, for the Earth, compressing its entirety into the volume of a chickpea would generate a black hole of comparable size. Similarly, for a typical star with several times the mass of the Sun, the resulting black hole would span a few miles—a dimension akin to an average city.
Interestingly, amalgamating all the matter in the universe in an attempt to create the largest possible black hole would yield a black hole roughly the size of the universe itself.
Ever wonder where all the active supermassive black holes are in the universe? Now, with the largest quasar catalog yet, you can see the locations of 1.3 million quasars in 3D.
The catalog, Quaia, can be accessed here.
“This quasar catalog is a great example of how productive astronomical projects are,” says David Hogg, study co-author and computational astrophysicist at the Flatiron Institute, in a press release. “Gaia was designed to measure stars in our galaxy, but it also found millions of quasars at the same time, which give us a map of the entire universe.” By mapping and seeing where quasars are across the universe, astrophysicists can learn more about how the universe evolved, insights into how supermassive black holes grow, and even how dark matter clumps together around galaxies. Researchers published the study this week in The Astrophysical Journal.
The heliosphere—made of solar wind, solar transients, and the interplanetary magnetic field—acts as our solar system’s personal shield, protecting the planets from galactic cosmic rays. These extremely energetic particles accelerated outwards from events like supernovas and would cause a huge amount of damage if the heliosphere did not mostly absorb them.
