posted on Oct, 19 2012 @ 07:45 PM
This is very interesting indeed. I've always wondered what affect gravitational lensing is having on our view of very old and far away objects. We
can't assume that we have a clear view with nothing in between us and the far away galaxy. And the further away a galaxy is, increases the likelihood
that a heavy mass object or many objects may be in the line of sight, causing gravitational lensing, which distorts the image and changes the apparent
redshift. Are distant galaxies really as far away as they seem by their redshift or is gravitational lensing making them seem farther (and thus older)
then they really are? Are early galaxies really so disorganized or are their images being smeared and distorted by gravitational lensing?
Here is a quote from the ASU School of Earth and Space Exploration:
Cosmic magnifying lenses distort view of distant galaxies
A very massive object – or collection of objects – distorts the view of faint objects beyond it so much that the distant images are smeared into
multiple arc-shaped images around the foreground object. According to Rogier Windhorst, one of the letter’s authors and a professor at the School of
Earth and Space Exploration in Arizona State University’s College of Liberal Arts and Sciences, this effect is analogous to looking through a glass
coke bottle at a light on a balcony and noticing how it is distorted as it passes through the bottle. Cosmologists such as Windhorst believe that
gravitational lensing likely distorted the measurements of the flux and number density of the most distant galaxies seen in the recent deep near-IR
surveys with the Hubble Space Telescope Wide Field Camera 3.
When you look back to when the universe was young, you are seeing extremely early objects (also known as ``First Light’’ objects) that are very
far away. The older and farther away the object, the more foreground universe there is to look through, which means the greater the chance that there
will be something heavy in the foreground to distort the background image. This research suggests that gravitational lensing is likely to dominate the
observed properties of very early galaxies, those that are at most 650-480 million years old (now seen with Hubble at redshifts of z > 8-10,
respectively). The halos of foreground galaxies when the universe was in its heydays of star formation (about 3-6 billion years old and at a lower
redshift of z=1-2) will gravitationally distort most of these very early objects.
I don't think we fully appreciate that when we look at the night sky, what we are actually viewing is a froth of gravitational lens bubbles which are
magnifying, distorting, dimming, brightening, and smearing nearly every viewable object. Imagine a photograph of stars in a shallow pool of water
overlayed with a layer of soap bubbles. Roughly, that is what gravitational lensing is doing, but we are unaware of the bubbles.
If a perfect spiral galaxy existed 13 billion light years away, would it look like an organized spiral galaxy or would it look chaotic and distorted,
the way galaxies at that distance always seem to look?