The James Webb Telescope Discovers Supernovas in the Early Universe
Exploring the cosmos when it was young, especially fleeting events like stellar explosions with redshift greater than 2, represents a new frontier. These phenomena, whose light is stretched into the infrared, escape the view of most current optical observatories. The James Webb Space Telescope (JWST) has the unique capability to observe this light in the near-infrared, acting as a cosmic time machine to reveal how the first stars and galaxies evolved. 🔭
An Innovative Strategy for Hunting Explosions
A pioneering study did not start from a program specifically designed to search for changes over time. Instead, astronomers combined data from two large JWST extragalactic surveys: PRIMER and COSMOS-Web. Together, they cover a sky area of about 133 square arcminutes. By comparing images taken nearly a year apart, they generated difference images that highlight only what changed: new sources of light that appeared or disappeared.
Key Results from the Analysis:- 68 supernovas were identified with photometric redshifts estimated for their host galaxies, some with values up to z ~ 5.
- For most of these candidates, there is only one epoch of observation, which limits the detailed study of their light curves.
- Researchers prioritize the most promising candidates using the galaxy's redshift, its classification, color, and apparent brightness to plan follow-up observations.
This method demonstrates that even without an optimized observation cadence, the JWST can transform deep imaging surveys into powerful hunters of transient phenomena in the distant universe.
Extraordinary Candidates and the Path Forward
Among the most notable discoveries are two supernovas that stand out for their characteristics. SN 2023aeab is a core-collapse supernova, relatively bright and with blue colors, located at a redshift greater than 3 (z > 3). On the other hand, SN 2023aeax appears to be a "normal" type Ia supernova but young, situated at z > 2. These findings are just a sample of the potential.
Implications for Future Research:- The sample distribution suggests that a JWST program