Why Does NGC 7603's Bridge Defy Redshift Expectations?

[SeventhSigma]

This is a galaxy cluster that has an apparent bridge linking it

Even though the redshifts are very different for different objects within it. What is the most likely explanation for this?

 

[Drakkith]

To take a completely random guess, I'd say they were background galaxies simply placed in those spots by coincidence.
Given the much greater redshift value, smaller size and luminosity, and the fact that the filament is approximately the same redshift as NGC 7603, I could believe it.
But I'm not a professional. The paper linked from the webpage indicates that objects 2 and 3 are emission lines, not absorption lines like the two galaxies are, so I don't know.

 

[Chronos]

NGC 7603 is one of Arp's oddities cited as 'evidence' redshift as an unreliable distance indicators. I am well aware of this 'anomaly' and it is rubbish.

 

[Drakkith]

NGC 7603 is one of Arp's oddities cited as 'evidence' redshift as an unreliable distance indicators. I am well aware of this 'anomaly' and it is rubbish.

Can you elaborate on why it is rubbish?

 

[SeventhSigma]

Would also like an elaboration