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High Redshift

All articles tagged with #high redshift

JWST uncovers a fully formed galactic bar in the early universe, challenging bar-formation theory
science1 month ago

JWST uncovers a fully formed galactic bar in the early universe, challenging bar-formation theory

JWST spotted a long, fully formed stellar bar in GN20, a massive galaxy from the early universe, contradicting three predictions that bars shouldn’t exist in young, gas-rich disks. Independent dust maps corroborate the structure, suggesting turbulence-driven gas dynamics can stabilize bars and drive central starbursts and black hole growth. The finding implies early galaxies matured faster than models predicted and will prompt revisions to simulations, with follow-up kinematic studies planned (e.g., ALMA).

via Space Daily|
#galactic-bar#galaxy-evolution#gn20
Distant Gamma-Ray Burst at Redshift 7.3 Rewrites Early-Universe Star Deaths
space5 months ago

Distant Gamma-Ray Burst at Redshift 7.3 Rewrites Early-Universe Star Deaths

A ten-second, ultra-distant gamma-ray burst (GRB 250314A) at z=7.3 (~13.1 billion years old) sparked a rapid, global follow-up, with JWST resolving its explosion as a supernova similar to modern Type II events. The findings imply massive stars were dying and enriching their surroundings within the universe’s first billion years, challenging Population III star death models and suggesting comparatively mature stellar processes occurred far earlier than previously thought.

via Indian Defence Review|
#astronomy#early-universe#gamma-ray-burst
JWST Spots Nine Cosmic Platypuses That Defy Classification
astronomy5 months ago

JWST Spots Nine Cosmic Platypuses That Defy Classification

Astronomers using the James Webb Space Telescope have identified nine compact, point-like objects at redshifts 3.6–5.4 whose properties don’t fit neatly into stars, galaxies, quasars, or standard AGNs. They display narrow emission lines, lack resolvable host galaxies, and their light profiles differ from a true point source by about 10–20%, raising the possibility of a new class of objects—perhaps low-luminosity, hostless AGNs or unusual young galaxies—though their exact nature remains unclear pending deeper imaging and broader wavelength data. The discovery is framed as the cosmic equivalent of a platypus.

via Big Think|
#agn#astronomy#galaxies
"Groundbreaking Discovery: Astronomers Uncover Enormous Dormant Galaxy"
astronomy2 years ago

"Groundbreaking Discovery: Astronomers Uncover Enormous Dormant Galaxy"

Astronomers have discovered a new massive and quiescent galaxy, COSMOS-1047519, at a high redshift of 4.53. This finding is significant as it adds to the limited number of spectroscopically confirmed high-redshift quiescent galaxies and provides insights into the early stages of the universe. The galaxy has a stellar mass of about 60 billion solar masses and a low star formation rate of only 10 solar masses per year. The observations suggest that COSMOS-1047519 experienced a starburst followed by rapid quenching, making it one of the youngest quiescent galaxies at a redshift higher than 3.0. The researchers propose that gas depletion due to starburst and/or AGN feedback triggered by galaxy-galaxy interactions or mergers may be responsible for quenching.

via Phys.org|
#astronomy#galaxy-evolution#high-redshift
"Discovery of Dual Quasar Sheds Light on Black Hole Collision in Galaxy Merger"
astronomy3 years ago

"Discovery of Dual Quasar Sheds Light on Black Hole Collision in Galaxy Merger"

Astronomers have discovered a pair of quasars in a disk-disk galaxy merger at a redshift of 2.17, making it one of the closest quasar pairs ever found. The discovery was made using data from the Hubble Space Telescope, Chandra X-ray Observatory, and other telescopes. The quasar pair is believed to be a binary system, rather than a gravitational lens, and could provide insights into the co-evolution of supermassive black holes and their host galaxies.

via Nature.com|
#astronomy#dual-quasars#galaxy-merger