Observing large scale structure in the local universe; Galaxies in the CfA2 Great Wall

[Niels11]

As I’ve been getting back into observing in the last few weeks I’ve been looking at my logbooks from a few years ago, and this is the funnest little project I did – I’m interested to hear if anyone else has any similar projects or experiences for viewing structures larger than galaxy clusters: superclusters, walls, filaments, voids? 

This was a small list of galaxies in the CfA2 Great Wall, a huge structure 500-750 Mly wide according to Wikipedia, across the sky between RA 8-17h from Leo to Hercules. I can’t remember how I came up with the list – I think I limited my search to the part of the wall between Coma and Hercules and I must have used either Sky Safari or the SDSS database to search for Galaxies in this region of the sky with a magnitude which might be observable with an 8” scope and with red shifts of about z=0.022 (98 Mpc, comoving distance) in the region of the Coma cluster (NGC 4889) to z=0.031 (141 Mpc) in the region of the Hercules cluster (NGC 6166). I could maybe extend the list eastwards through Leo, but I haven’t tried to do that yet.

This is the list of NGC galaxies I came up with and whether I managed to observe them with my 8” Newtonian – its really just a string of galaxies across the sky, which fit the distance and direction to be part of the CfA2 Great Wall, the rest is imagination, like a lot of the pleasure of astronomy for me, especially in a medium sized scope under light pollution

4889, mag 11.75, z=0.022, observed, Bortle 5, SQM 19.5 

4874, mag 13.59, z=0.024, observed, Bortle 5 SQM 19.5 

5004, mag12.89, z=0.024, observed, Bortle 5, SQM 19.5 

5032, mag 12.8, z=0.021, searched but not found, Bortle 5, SQM 19.5 

5223, mag 13.0, z=0.024, observed, Bortle 5, SQM 19.5 

5352, mag 13.0, z=0.027, observed, Bortle 5, SQM 19.5 

5421, mag 13.2, z=0.026, not searched for 

5515, mag 12.9, z=0.026, searched but not found, in Bortle 5, or Bortle 1-2, SQM 21.77 

5541, mag 12.7, z=0.026, observed, Bortle 1-2, SQM 21.77

5654, mag 13.0, z=0.030, observed, Bortle 1-2, SQM 21.77

5755, mag 13.5, z=0.032, searched but not found in Bortle 1-2, SQM 21.77

5888, mag 13.4, z=0.029, observed, Bortle 1-2, SQM 21.77

5993, mag 13.1, z=0.032, observed, Bortle 1-2, SQM 21.77

6173, mag 12.1, z=0.029, not searched for

6166, mag 11.8, z=0.031, observed, Bortle 5, SQM 19.5

6137, mag 12.39, z=0.031, not searched for

6109, mag 12.69, z=0.030, not searched for

These observations were made over a few new moon sessions: a couple of sessions in my suburban back garden in early June, and a couple of sessions on holiday in the Lizard in early August. I was using my 8” f5 Skywatcher, Leica Zoom, barlowed at 1.5 (6-12mm) or 2.5 (3.6-7.1mm) and UWAN 16mm.

Doing this I felt quite in awe of the vastness of the universe and that I was able to reach out and touch that even with my quite modest little set-up - that is how it is with any Galaxy, and this was like another step up in perspective.

I'm hoping to revisit this project later this year, and maybe expand it. And I'm looking for any other projects of a similar kind which any of you might have to suggest?

[josefk]

Fantastic project @Niels11. I have absolutely nothing to contribute regarding  similar projects 😔but i recommend you this resource if you haven't seen it. I really enjoy reading (and trying to keep up mentally) with the mapping and descriptions of this guy pursuing similar projects to yourself re large coherent/related structures: https://www.cloudynights.com/topic/565226-classic-rich-field/

[Niels11]

Oh yes that is quite interesting @josefk- looking at structure and where things are in relation to eachother within the Milky Way - there’s a project there! 😊

[mdstuart]

Have a look at this for more ideas.

http://www.atlasoftheuniverse.com

Enjoy

Mark

[DavidR100]

What a marvellous project! Using your own galaxy observations to build up a picture of such a large scale structure is a splendid and novel (to me at least) idea.

Can I suggest that you continue in the same vein - observing yet more galaxies along the Great Wall and perhaps plotting your observations on the map in your post.  It would be fascinating to see if you could continue the exercise for other (neighbouring) large scale structures.

Out of interest, I checked my own observations and I have seen ten of those Great Wall galaxies, though unfortunately I didn't realise it at the time 🙁

Keep it up!