Starship Asterisk*

ta152h0 wrote:I still have this question bouncing around in my head. If the lensed galaxy is 10-20 times further than the lenser galaxy and we know the Universe is considered to be 14.6 billion years old, at what distance lensed galaxies cease to be seen ? Or is this too much relativity for this biomass computer ?

Redshifts are attributable to the Doppler effect, familiar in the changes in the apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles; an observed redshift due to the Doppler effect occurs whenever a light source moves away from an observer.

Cosmological redshift is seen due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase of their distance from Earth.

Finally, gravitational redshifts are a relativistic effect observed in electromagnetic radiation moving out of gravitational fields.

Conversely, a decrease in wavelength is called blueshift and is generally seen when a light-emitting object moves toward an observer or when electromagnetic radiation moves into a gravitational field.

stephen63 wrote:One more good analogy would be to take a slinkie and stretch it apart. The coils would represent what is happening to the wavelength of light.

http://en.wikipedia.org/wiki/Redshift#section_4
In the widely accepted cosmological model based on general relativity, redshift is mainly a result of the expansion of space: this means that the farther away a galaxy is from us, the more the space has expanded in the time since the light left that galaxy, so the more the light has been stretched, the more redshifted the light is, and so the faster it appears to be moving away from us.

MargaritaMc wrote:Oddly, the concept of redshift was something I read about some years ago, and it made sense, even tho I had no background in astronomy.

MargaritaMc wrote:I've been reading about the research relating to this image and I'd be grateful if someone could tell me what z means in the following quotation

Spectroscopic measurements are obtained for 26 lensed images, including a distant galaxy at z = 5.4.

http://m.iopscience.iop.org/0004-637X/6 ... .text.html

Spectroscopic measurements are obtained for 26 lensed images, including a distant galaxy at z = 5.4.

ta152h0 wrote:Mr Peterson ( of Cloubait Observatory )writes
" Lensed galaxies are typically 10-20 times farther away from us than the lensing galaxy (or galaxy cluster "

So, if we see a lensing galaxy is about 1.4 billion light years away, is it correct to say the lensed galaxy we see is at, near, beyond the calculated age of the Universe ?

bystander wrote:

RET wrote:> toward the constellation Vulpecula.
should be Pisces, I suppose.

Boomer12k wrote:Why should you suppose that?
http://heritage.stsci.edu/2013/09/fast_facts.html

RET wrote: http://www.spacetelescope.org/videos/heic1304a/
http://simbad.u-strasbg.fr/simbad/sim-id?Ident=aco+68

Hmm, seems STScI may be in error here. The coordinates RA 03h 36m 59s.4 Dec +09° 08' 30" would indicate Cetus. However, SIMBAD lists the coordinates of Abell 68 as RA 00h 37m 06s.2 Dec +09° 09' 33" which would place it in Pisces. Neither of those are anywhere close to Vulpecula. I'm confused.

bystander wrote:Hmm, seems STScI may be in error here. The coordinates RA 03h 36m 59s.4 Dec +09° 08' 30" would indicate Cetus.

RET wrote:> toward the constellation Vulpecula.
should be Pisces, I suppose.

Boomer12k wrote:Why should you suppose that?
http://heritage.stsci.edu/2013/09/fast_facts.html

RET wrote: http://www.spacetelescope.org/videos/heic1304a/
http://simbad.u-strasbg.fr/simbad/sim-id?Ident=aco+68

Boomer12k wrote:

RET wrote:> toward the constellation Vulpecula.

should be Pisces, I suppose.

Why should you suppose that?

http://heritage.stsci.edu/2013/09/fast_facts.html

Fixxxer wrote:Does the nearly edge-on galaxy that's just up and left of image center have a pair of jets coming from its core, or is that an artifact of the image?
(It's the galaxy that's on the upper-left edge of label #4's ellipse.)

zbvhs wrote:How far away are the lensed galaxies? Does the color provide a clue? Is it possible that lensed galaxies might be reflections of objects in front of the lensing galaxy?