Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1038/457388a | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The James Webb Space Telescope has discovered a surprising population of bright galaxies in the very early Universe (≲500 Myr after the Big Bang) that is hard to explain with conventional galaxy-formation models and whose physical properties are not fully understood. Insight into their internal physics is best captured through nebular lines, but at these early epochs, the brightest of these spectral features are redshifted into the mid-infrared and remain elusive. Using the mid-infrared instrument onboard the James Webb Space Telescope, here we present a detection of Hα and doubly ionized oxygen ([O iii] 4959,5007 Å) from the bright, ultra-high-redshift galaxy candidate GHZ2/GLASS-z12.
View Article and Find Full Text PDFMagnetospheric origin of a fast radio burst constrained using scintillation.
Nature
January 2025
Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.
Article Synopsis
- Fast radio bursts (FRBs) are brief bursts of radio waves from distant galaxies, and their emission mechanisms are still debated, focusing on processes near a central engine versus shocks at large distances.
- Researchers measured two scintillation scales for FRB 20221022A, one linked to the Milky Way and the other to its host galaxy, which allowed them to determine the FRB's emission region size to be less than 3 x 10 kilometers.
- This size contradicts the large-distance model and suggests that the emission likely occurs close to a central compact object, supported by an observed S-shaped polarization angle, indicating a magnetospheric emission process.
A pulsar-like polarization angle swing from a nearby fast radio burst.
Nature
January 2025
Perimeter Institute for Theoretical Physics, Waterloo, Ontario, Canada.
Article Synopsis
- Fast radio bursts (FRBs) are intense signals from deep space that last for milliseconds and share some characteristics with pulsars, suggesting they may originate from neutron stars.
- Despite similarities, FRBs like 20221022A display different patterns in their linear polarization position angle (PA), particularly a 130° rotation that aligns with pulsar behaviors, hinting at magnetospheric origins.
- This study rules out short-period pulsars as potential sources for FRB 20221022A, supporting the idea that its unique PA evolution fits the rotating vector model commonly used for pulsars.
A dormant overmassive black hole in the early Universe.
Nature
December 2024
NRC Herzberg, Victoria British Columbia, Canada.
Recent observations have found a large number of supermassive black holes already in place in the first few hundred million years after the Big Bang, many of which seem to be overmassive relative to their host galaxy stellar mass when compared with local relation. Several different models have been proposed to explain these findings, ranging from heavy seeds to light seeds experiencing bursts of high accretion rate. Yet, current datasets are unable to differentiate between these various scenarios.
View Article and Find Full Text PDFFormation of a low-mass galaxy from star clusters in a 600-million-year-old Universe.
Nature
December 2024
Department of Astronomy and Physics, Saint Mary's University, Halifax, Nova Scotia, Canada.
The most distant galaxies detected were seen when the Universe was a scant 5% of its current age. At these times, progenitors of galaxies such as the Milky Way were about 10,000 times less massive. Using the James Webb Space Telescope (JWST) combined with magnification from gravitational lensing, these low-mass galaxies can not only be detected but also be studied in detail.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!