3C 120 – quasar concentration and a radio bridge

This system has been part of huge amount of different studies, so I will concentrate only on the discordant redshift issues for this system. For those, who are interested to look at the system’s other interesting properties, Arp (1987a) gives a brief overview of the system in the introduction section, there’s for example the issue [...]

NGC 5015 – exact pair alignments

NGC 5015 (object 1 in Figure 1) has not been studied much, and I’m not aware of it being mentioned as DRS before. So, let us see what we have there. Object 2 has similar redshift to NGC 5015, so it’s not a discordant redshift object. It looks very interesting object, though. It seems to [...]

Tools and methods in A.R.I.

Now that I have made some posts about individual discordant redshift systems, I thought it might be good to explain some things related to the contents of those posts. So here goes: Methods My DRS posts usually contain following sections: – Main article section, where I introduce the previously published results and arguments on the [...]

IC 2402 – QSO, Galaxy, and a Radio filament

Olsen (1970) studied the positions of 4C radio sources, and noted about radio source 4C 31.32: The primary identification is the *13.5-mag E galaxy, NGC 2402 [should be IC 2402], which appears 3″E and 34″S of the radio position. An 18-mag blue stellar object appears 30″W and 17″N of the radio position. Grueff & Vigotti [...]

NGC 0048 – Which one doesn’t belong to the group?

Figure 1 presents a group of galaxies near NGC 0048 (the numbered objects). One of the galaxies has redshift of cz ~ 1800 km/s while others have redshift of cz ~ 5000 km/s. Looking at the image, can you tell which one it is? Figure 1. The objects with measured redshifts near of NGC 0048. [...]

NGC 0045 – An example of a line alignment by chance?

To my knowledge, NGC 0045 system hasn’t been discussed as a DRS before. However, de Vaucouleurs (1959) discussed NGC 0045 among a few other galaxies that he suggested belong to a galaxy group now known as the Sculptor Group, and he noticed that the mass of the group derived from luminosity is far smaller than [...]