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Cave divers equipped with brilliant headlamps often explore cavities in rock less than a mile beneath our feet. It’s easy to be wholly unaware of these cave systems – even if you sit in a meadow above them – because the rock between you and the spelunkers prevents light from their headlamps from disturbing the idyllic afternoon.

Apply this vision to the conditions in the early universe, but switch from a focus on rock to gas. Only a few hundred million years after the big bang, the cosmos was brimming with opaque hydrogen gas that trapped light at some wavelengths from stars and galaxies. Over the first billion years, the gas became fully transparent – allowing the light to travel freely. Researchers have long sought definitive evidence to explain this flip.

New data from the James Webb Space Telescope recently pinpointed the answer using a set of galaxies that existed when the universe was only 900 million years old. Stars in these galaxies emitted enough light to ionize and heat the gas around them, forming huge, transparent “bubbles.” Eventually, those bubbles met and merged, leading to today’s clear and expansive views.

“The Universe Came From a Black Hole” String Theory Founder Reveals James Webb Telescope’s New Image. Deep within dense star clusters, something extraordinary dwells: Stars. But these, are no ordinary stars, but colossal celestial beings, known as supermassive stars. And now, their existence has been unveiled by the piercing gaze of the James Webb Space Telescope.

According to the standard model of cosmology, after the universe came out of the big bang, it took between 500 million to 1 billion years for the first stars to form. That however, is changing.

We are not just finding single stars, but clusters of them in the early universe and that, has the whole scientific community stunned.

#space #jameswebbspacetelescope #nasa.

0:00 Stars in Globular Clusters.
2:24 The Abundance Anomalies.
3:55 Most Ancient and Distant Galaxies.

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Black holes, cosmic power stations, fuel the luminosity of quasars and active galactic nuclei (AGNs) through their intricate interaction of matter, gravity, and magnetic forces. Despite black holes themselves not possessing a magnetic field, the surrounding dense plasma in the accretion disc does. As this plasma orbits the black hole, its charged particles generate an electric current and consequently a magnetic field.

This magnetic field, assumed to be stable due to the unvarying plasma flow, caused scientists to scratch their heads when they found evidence of its directional change. Such a phenomenon, known as a magnetic reversal, is akin to an imaginary pole of a magnet switching from north to south or vice versa. While not uncommon in stars, and even witnessed in the Sun’s 11-year sunspot cycle or Earth’s infrequent magnetic shifts, such an event was thought improbable for supermassive black holes.

In 2018, a computer-aided sky survey detected a startling transformation in a galaxy 239 million light-years away named 1ES 1927+654, which had suddenly become a hundredfold brighter. Swift Observatory soon reported x-ray and ultraviolet light emissions from this region. Initial speculations suggested a tidal disruption event caused by a star venturing too close to the galaxy’s central supermassive black hole, disrupting gas flow into the accretion disc, as the reason for this unusual luminosity.

This image of galaxy cluster MACS J1206.2–0847 (or MACS 1,206 for short) is part of a broad survey with NASA’s Hubble Space Telescope.

The distorted shapes in the cluster are distant galaxies from which the light is bent by the gravitational pull of an invisible material called dark matter within the cluster of galaxies. This cluster is an early target in a survey that will allow astronomers to construct the most detailed dark matter maps of more galaxy clusters than ever before.

These maps are being used to test previous, but surprising, results that suggest that dark matter is more densely packed inside clusters than some models predict. This might mean that galaxy cluster assembly began earlier than commonly thought.