Posted on 10/14/2012 3:04:01 AM PDT by SunkenCiv
Explanation: What did the first galaxies look like? To help answer this question, the Hubble Space Telescope has just finished taking the eXtreme Deep Field (XDF), the deepest image of the universe ever taken in visible light. Pictured above, the XDF shows a sampling of some of the oldest galaxies ever seen, galaxies that formed just after the dark ages, 13 billion years ago, when the universe was only a few percent of its present age. The Hubble Space Telescope's ACS camera and the infrared channel of the WFPC3 camera took the image. Combining efforts spread over 10 years, the XDF is more sensitive, in some colors, than the original Hubble Deep Field (HDF), the Hubble Ultra Deep Field (HUDF) completed in 2004, and the HUDF Infrared completed in 2009. Astronomers the world over will likely study the XDF for years to come to better understand how stars and galaxies formed in the early universe.
(Excerpt) Read more at 129.164.179.22 ...
[Credit: NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (UCSC), R. Bouwens (Leiden Obs.), and the XDF Team]
All of 'em more than 6014 light-years distant.
|
Makes me wonder what they look like in the present.
This is true. For perspective, when you look up towards the sun, you’re seeing what it looked like (and where it was) eight minutes prior.
Ah, I remember the good old days!
We didn’t have easy like you kids do.
We had to walk through knee deep quasars up hill to school; both ways!
Thank You, Civ, for today’s present.
:’)
My pleasure!
Also keep in mind that light from some of these galaxies and photo-galaxies have been red-shifted to significantly longer wavelengths than they started out due to the universe's expansion. What we are seeing now in the 'visible' range may have started out in the UV or even shorter. Galaxies can emit very different images in visible vs UV and other ranges.
From NASA.gov:
“An astronomical object can look very different depending on what wavelength is used in its detection. The object’s appearance often changes across the electromagnetic spectrum because various physical processes result in emission in different wavelength regions. Images of emission can be made by mapping brightness to colors (see “Making an Image”). For example, the optical image of the Andromeda galaxy (below left) shows glowing stars. And dark dust lanes trace out a spiral arm structure. An infrared image of the galaxy (below right) shows several concentric rings of dust rather than spiral arms. The dust is too cold (-260 degree C) to be detected in optical light.
Below are five images of the galaxy M 33. [see link]
Each image is taken in a different wavelength region.
In the X-ray image, we see very hot, diffuse interstellar gas, and bright point-like X-ray sources, such as X-ray binaries.
The brightness in the ultraviolet image indicates star formation activity. Stars are visible in the optical image.
Red supergiant stars and dust heated by massive star formation are highlighted in the near-infrared image, which looks similar to the optical image.
The radio image maps out hydrogen gas in the galaxy. The red coloring is indicative of gas moving away from our line of sight. The blue colors gas moving toward us (a phenomena described by Doppler shift).”
http://mwmw.gsfc.nasa.gov/mmw_across.html
Is about 1-1/4 seconds.
For those who aren't aware, one light-second is about 186,000 miles.
So that's 186,000 x 60secs x 60mins x ~3.5 (miles). = 2,343,600,000 miles (~2.3 billion miles)
So that’s 186,000 x 60secs x 60mins x ~3.5 (miles)
correction: (hours) not (miles)
Ah, I remember the good old days!
We didn’t have easy like you kids do.
We had to walk through knee deep quasars up hill to school; both ways!
Lol. I'm a big Monty Python fan too.
Four Yorkshiremen:
http://www.youtube.com/watch?v=13JK5kChbRw
Same as my Dad, apparently!
Thank You.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.