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sidmel
2004-Sep-02, 03:28 PM
Just curious if anybody has a link to site that has graphs of the observed red (or blue) shift of galaxies over time. IE - Observed change in the red shift of galaxy x over the last 50 years.

Thanks!

ngc3314
2004-Sep-02, 04:04 PM
Just curious if anybody has a link to site that has graphs of the observed red (or blue) shift of galaxies over time. IE - Observed change in the red shift of galaxy x over the last 50 years.

Thanks!

Far below the error bars. The closest anyone has come was an Arecibo observation of redshift hydrogen absorption in front a background quasar, which might chance by a just-measurable amount (part in 10^7, if memory serves) due to plausible amounts of accelerarion or deceleration (they were of course then only thinking of the latter). Hasn't been 50 years yet fopr a remeasurement. The special thing here was that the line was unusually narrow in frequency, so its centroid had a very small error, and the high accuracy to which radio technology can measure frequencies with narrow bandwidth.

sidmel
2004-Sep-02, 04:35 PM
I was just curious if there was such a study. It would be interesting to see the change in a galaxy's red shift since we've been observing it as our two galaxies expand further appart. Ah, well. I'll keep looking.