Galaxy from 700 million year old universe

In summary, at a recent conference, a redshift of 7.6 was reported for one of the earliest galaxies ever seen. This means that its light has been traveling for 12.9 billion years and was emitted when the universe was only about 700 million years old. By using different calculators and accepted parameter values, we can estimate the distances and recession speeds of this galaxy. The galaxy was also magnified by a foreground galaxy and the James Webb telescope, set to launch in 2013, will provide more detailed observations. The recession speed of the galaxy was 3.3c when the light was emitted and is now 2.1c. The distance of the galaxy at the time of emission was 3.4
  • #1
marcus
Science Advisor
Gold Member
Dearly Missed
24,775
792
One of the earliest, maybe the earliest galaxies seen so far.
Redshift 7.6 reported at conference. If confirmed then the light from it has been traveling some 12.9 billion years and was emitted when expansion was only about 700 million years old.
Put 7.6 into either of these calculators to get distances and recession speeds
Ned Wright's
http://www.astro.ucla.edu/~wright/CosmoCalc.html
just plug in 7.6 for z, over on the left

Ned Wright puts in the default values of H=71, and Omega_matter = 0.27 and Lambda = 0.73. they are accepted parameter values, widely used. With Morgan's calculator you have to type in those three parameter values
http://www.uni.edu/morgans/ajjar/Cosmology/cosmos.html
Over on the left, put in 0.27 for matter, 0.73 for Lambda, and 71 for Hubble.

Here is a press release about it, and a blog report from the conference:
http://hubblesite.org/newscenter/archive/releases/2008/08/full/
http://scienceblogs.com/catdynamics/2008/02/liveblogging_the_high_redshift_1.php

Larry Bradley, Garth Illingworth, Rychard Bouwens are some names to search on, to find out more.
They had 10X gravitational lensing magnification by a galaxy in the foreground. The James Webb telescope (launch 2013?) will be able to see detail in this young galaxy.

The recession speed was 3.3c THEN when it emitted the light we are now receiving from it, and its recession speed now is 2.1c
(you can check this with Morgan's calculator if you wish)
When it emitted the light it was about 3.4 billion lightyears from us. And today, as we are receiving the light, it is about 29.4 billion lightyears from us.

the ratio of those two distances should be 1+z = 8.6 because that is the factor by which distances have grown during the time the light has been in transit.
 
Last edited by a moderator:
Space news on Phys.org
  • #2
Wow, that's amazing! It's incredible to think that we can actually see something that is 12.9 billion years old. It's a reminder of just how far our technology has come and what we are capable of. I'm looking forward to the launch of the James Webb telescope and seeing what more we can learn about this distant galaxy!
 

1. What is a galaxy and how is it formed?

A galaxy is a large system of stars, planets, gas, and dust held together by gravity that contains billions of stars. It is formed from the collapse and merging of smaller structures, such as gas clouds, over billions of years.

2. How far away is a galaxy from Earth?

The distance between galaxies can vary greatly, but on average, the closest galaxy to Earth is about 25,000 light-years away. However, the farthest known galaxy is estimated to be 13.4 billion light-years away.

3. How old is the universe and when did the first galaxies form?

The current estimated age of the universe is about 13.8 billion years old. Based on observations, the first galaxies are thought to have formed around 400-500 million years after the Big Bang, making them approximately 13.3 billion years old.

4. What can studying galaxies from 700 million years ago tell us about the universe?

Studying galaxies from 700 million years ago can provide valuable insights into the early stages of the universe, including its formation and evolution. It can also help us understand the processes that led to the formation of galaxies and how they have changed over time.

5. How do scientists study galaxies from 700 million years ago?

Scientists use powerful telescopes, such as the Hubble Space Telescope, to observe and study galaxies from 700 million years ago. They also use advanced technology and techniques, such as gravitational lensing, to enhance their observations and gather more information about these distant galaxies.

Similar threads

Replies
12
Views
3K
  • Astronomy and Astrophysics
Replies
12
Views
1K
Replies
12
Views
2K
  • Cosmology
Replies
1
Views
1K
  • Astronomy and Astrophysics
Replies
2
Views
1K
Replies
38
Views
4K
Replies
8
Views
2K
Back
Top