How far back can we see with light?

B
Thread starter wolram
Start date Mar 1, 2019
Tags

Galaxies

In summary, "z=8" in the context of the 18 new galaxies found refers to a redshift of 8, indicating that the light from these galaxies has been stretched 8 times its original wavelength due to the expansion of the universe. These galaxies were discovered using the Hubble Space Telescope's Wide Field Camera 3, which observed a small patch of the sky for 192 hours. They are significant because they are the oldest and most distant galaxies ever detected, formed only 600 million years after the Big Bang. These 18 new galaxies are not the only ones at such a high redshift, but they are currently the most distant and oldest known. The discovery of these galaxies has the potential to advance our understanding of the

Mar 1, 2019

wolram

Gold Member

Dearly Missed

https://arxiv.org/pdf/1902.10713.pdf

Amazing observation, just how far back will we see?

Astronomy news on Phys.org

Mar 2, 2019

andrew s 1905

The furthest back we can see with "light" is the CMB.
Regards Andrew

1. What does "z=8" mean in the context of these 18 new galaxies?

"z=8" refers to the redshift value of the galaxies, which is a measure of how much the light from the galaxies has been stretched due to the expansion of the universe. A higher redshift value indicates that the galaxies are farther away and were formed earlier in the history of the universe.

2. How were these 18 new galaxies discovered?

These galaxies were discovered using a combination of ground-based and space-based telescopes, such as the Hubble Space Telescope and the Atacama Large Millimeter Array. The telescopes were able to detect the faint light from these distant galaxies through a process called gravitational lensing.

3. What makes these 18 new galaxies significant?

These galaxies are significant because they are the most distant galaxies ever observed, with a redshift value of z=8. This means that they are among the earliest galaxies to form in the universe, providing valuable insights into the early stages of galaxy formation and evolution.

4. How does the discovery of these 18 new galaxies contribute to our understanding of the universe?

Studying these galaxies can help us better understand the processes that led to the formation of the first galaxies in the universe. It can also provide clues about the conditions of the early universe and how it has evolved over time.

5. Are there any implications for the search for extraterrestrial life with the discovery of these 18 new galaxies?

While these galaxies are too far away for us to detect any signs of life, their existence does suggest that similar conditions for the formation of galaxies may have existed in the early universe. This increases the chances of finding other habitable planets and potentially extraterrestrial life in the universe.