Why Does NGC 7603's Bridge Defy Redshift Expectations?

  • Context: Graduate 
  • Thread starter Thread starter SeventhSigma
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the peculiar characteristics of NGC 7603, particularly the apparent bridge linking different objects within the galaxy cluster and the differing redshifts observed. Participants explore potential explanations for these observations, considering theoretical implications and the reliability of redshift as a distance indicator.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • One participant suggests that the differing redshifts could be explained by the presence of background galaxies coincidentally aligned with the cluster.
  • Another participant references the characteristics of the objects within the cluster, noting that some have emission lines while others have absorption lines, which may complicate the interpretation of redshift data.
  • Some participants assert that NGC 7603 is cited as an anomaly by Arp, arguing that it serves as evidence against the reliability of redshift as a distance indicator, although this viewpoint is challenged by requests for further elaboration.

Areas of Agreement / Disagreement

There appears to be disagreement regarding the interpretation of the redshift data and its implications for understanding NGC 7603. Some participants question the reliability of redshift as a distance indicator, while others seek clarification on these claims.

Contextual Notes

Participants express uncertainty about the implications of the differing redshifts and the nature of the objects involved, indicating that further elaboration is needed to fully understand the claims being made.

Who May Find This Useful

This discussion may be of interest to those studying galaxy clusters, redshift phenomena, and the implications of observational data in astrophysics.

SeventhSigma
Messages
256
Reaction score
0
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?
 
Last edited by a moderator:
Astronomy news on Phys.org
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.
 
Last edited:
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.
 
Chronos said:
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?
 
Would also like an elaboration
 

Similar threads

High School NGC 4590, more than 1,400 stars found in various evolutionary stages
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Challenges to the Redshift Method and Hubble's Law
  • · Replies 5 ·
Replies
5
Views
3K
Graduate Spectroscopic Observation of Anomalous Redshift in NGC 7603
  • · Replies 18 ·
Replies
18
Views
8K
Undergrad Too Much Dark Matter In CEG Mrk 1216
  • · Replies 2 ·
Replies
2
Views
3K
Undergrad New Developments In The Search For Planet X
  • · Replies 2 ·
Replies
2
Views
3K
Graduate UV Galaxy Surface brightness says no expansion
  • · Replies 30 ·
2
Replies
30
Views
7K
Graduate Confusion about redshift in a universe with accelerating expansion
  • · Replies 8 ·
Replies
8
Views
5K
Graduate Are Quasars and Galaxies Redshifts Truly Quantized?
  • · Replies 80 ·
3
Replies
80
Views
26K
Undergrad Questions regarding dark matter dynamics
  • · Replies 65 ·
3
Replies
65
Views
9K
High School For object 3.26 million light-years away, light redshifted by 70 km/s
  • · Replies 12 ·
Replies
12
Views
2K