Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2002 October 7 
Posted on 10/06/2002 11:34:06 PM PDT by petuniasevan
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2002 October 7
Explanation: Is the galaxy in the center connected to the quasar on the upper right? Disagreements about systems like this have raged for decades and have been used to challenge the foundations of modern cosmology. Some believe that the quasar Markarian 205 was recently ejected from galaxy NGC 4319, indicating that the high redshift of Markarian 205 is not indicative of its distance. Most astronomers have come to believe, however, that the two are not physically associated, and that the high redshift of Markarian 205 indeed indicates that it lies across our universe. In this predominant view, as with a tree branch that happens to point toward the Moon, their juxtaposition in the above image is just coincidence.
Besides the redshift difference, astronomers measured how much the ultraviolet light from Markarian 205 dimmed as it passed through interstellar gas in NGC 4319. The numbers they obtained from this data suggest that Mrk 205 is 1 BILLION light years away as opposed to NGC 4319's 80 million light years distance.
Of course, as with any good science, the jury's still out until the evidence for the "non-connected" theory is complete.
Anyway, enjoy tonight's beautiful Hubble image!
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