NASA | STScI | JWST | 2018 Apr 25
Gravitational lensing by a galaxy cluster could bring the early universe into focus for Webb
from more distant, background objects through gravity. NASA’s James Webb Space
Telescope may be able to detect light from the first stars in the universe if they are
gravitationally lensed by such clusters. Credit: NASA, ESA, and J. Lotz,
M. Mountain, A. Koekemoer, and the HFF Team (STScI)
One of the key science goals of NASA’s James Webb Space Telescope is to learn about "first light," the moment when the first stars and galaxies lit the universe. While the first galaxies will be within Webb’s reach, individual stars shine so faintly that Webb would not be able to detect them without help. That help could come in the form of natural magnification from gravitational lensing, according to a new theoretical paper.
A cluster of galaxies can provide the needed gravitational oomph to bring distant objects into focus via lensing. Typical gravitational lensing can boost a target’s brightness by a factor of 10 to 20. But in special circumstances, the light of a faraway star could be amplified by 10,000 times or more.
If Webb monitors several galaxy clusters a couple of times a year over its lifetime, chances are good that it will detect such a magnified star, or possibly the accretion disk of a black hole from the same era. This would give astronomers a key opportunity to learn about the actual properties of the early universe and compare them to computer models.
To See the First-Born Stars of the Universe
Arizona State University | 2018 Apr 25
On the Observability of Individual Population III Stars and Their Stellar-Mass
Black Hole Accretion Disks through Cluster Caustic Transits - Rogier A. Windhorst et al
- Astrophysical Journal Supplement Series 234(2):41 (Feb 2018) DOI: 10.3847/1538-4365/aaa760
arXiv.org > astro-ph > arXiv:1801.03584 > 10 Jan 2018