JWST and ALMA Detect Dusty, Fast-Accreting Quasar in the Early Universe
Observations combining James Webb Space Telescope spectroscopy and Atacama Large Millimeter/submillimeter Array data have identified a dust-reddened quasar designated J1440+0019 at a redshift of 6.5488, less than a billion years after the Big Bang. The object hosts a supermassive black hole with an estimated mass of 1.1 billion solar masses radiating at roughly 80 percent of its Eddington luminosity. The host galaxy contains approximately 400 million solar masses of dust and exhibits high-ionization absorption systems moving at up to 3,600 kilometers per second, indicating fast nuclear outflows during the epoch of cosmic reionization.
Combined Radio Telescopes Highlight Potential Starless Gas Disk
Data from the decommissioned Arecibo Observatory and China's FAST telescope have highlighted AGC 322753, an object located about 310 million light-years away containing approximately 2 billion solar masses in neutral hydrogen gas. Deep astronomical imaging reveals no matching starlight glow, though radio signals suggest the gas may be rotating in a disk. Artificial galaxy injection experiments imply an upper limit of 50 million solar masses in stars, meaning the system contains at least 40 times more hydrogen than stars and presenting a candidate dark galaxy.
Gaia Data Reveals Milky Way Thick Disk Formed Rapidly from the Inside Out
Analyzing Gaia Data Release 3 color-magnitude diagrams to derive precise stellar ages and metallicities, researchers found evidence that the Milky Way disk experienced a two-stage settling process. Between roughly 12.8 and 10.8 billion years ago, the vertical scale height dropped rapidly from over 1.26 kiloparsecs to about 0.5 kiloparsecs in a span of 2 billion years, followed by gradual thinning for younger populations. This indicates an upside-down formation scenario where ancient thick-disk stars were born in a turbulent, puffed-up early layer rather than being scattered outward later.
Solar Flare Ribbons Disclose Intermittent Energy Release in Corona
Researchers analyzing an M6.5-class solar flare observed by the Interface Region Imaging Spectrograph on June 22, 2015, quantified the spatial complexity of flare ribbons as they deposited energy in the chromosphere. The analysis suggests that energy deposition is not a uniform process, with flare ribbons breaking apart into fragments and depositing energy in bursts. The investigators concluded that the buildup of spatial complexity in the ribbons can serve as an observational proxy for current-sheet fragmentation occurring high in the corona.
Written with AI from original reports. Source names and report dates are shown with each story.
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