Exploring the Paradox of Distant Quasars in Nearby Galaxies

In the vast expanse of the universe, we often find celestial phenomena that challenge our understanding of cosmic distances and structures. One intriguing case in point is the apparent presence of a quasar within a galaxy that is vastly farther away. For example, consider a galaxy whose center is 900 million light years away, with a radius of 200 million light years. A quasar positioned at the far edge of this galaxy would be around 1.1 billion light years away from us. However, this proximity is a matter of perspective and measurement technique.

Skeptical Implications and Disk Opacity

The notion that a quasar could be closer than its redshift suggests might resonate with Halton Arp, given his skepticism towards established observational techniques. The first thing to consider is the optical properties of a galaxy's disk. Spiral galaxies, like our own Milky Way, are not uniformly opaque. This means that from our vantage point within the disk, we can see beyond the plane of the galaxy, except towards its center and a few regions with higher density, like the central galactic bulge.

Even amateur astronomers have captured images of the Maffei group, a small galaxy located in the direction of the constellation Perseus. Denser regions of spiral galaxies, such as atomic gas clouds, may contain gaps or holes through which we can observe extragalactic objects beyond the disk. For instance, the Lockman Hole, a region of low density in the intergalactic medium, has been used to detect sources beyond the Milky Way, even in the ultraviolet band. These phenomena strongly suggest that it is possible to see through a spiral galaxy's disk, thus making the presence of a quasar in the galaxy's spiral arm plausible.

Absorption Lines and Redshifts

Another important aspect is the spectral analysis of quasars. According to the Arp and Burbidge paper, the quasar's spectrum contains absorption lines that indicate it is shining through the interstellar gas within the galaxy. This is a crucial piece of evidence. While this does not definitively rule out the possibility of the quasar being in front of the galaxy, it strongly indicates that it is within the galaxy rather than behind it.

This alignment of absorption lines with the expected locations of gas clouds within the galaxy supports the interpretation that the quasar is in the same plane as the galaxy, rather than a much more distant object behind it. To date, no quasar along lines-of-sight through galaxies has been observed to lack these absorption lines, which further reinforces this view.

The Current Consensus

However, modern astronomical observations and consensus tend to support the view that the quasar is much farther away than indicated by its proximity within the galaxy. The current consensus is that the quasar in question is viewed through the galaxy NGC 7319, but is actually a more distant object as indicated by its redshift. The redshift measurement provides a more reliable indication of the object's distance in this case, resolving the apparent paradox.

This underscores the importance of redshift in determining celestial object distances and the need to critically evaluate observational data. While the quasar's presence within a nearby galaxy challenges our understanding, the established explanation based on redshift remains the more reliable and likely interpretation.

In conclusion, the fascinating interplay between observed proximity and established cosmic distances highlights the intricate and often unexplained nature of the universe. Further rigorous research and continued observation will undoubtedly shed more light on such phenomena.