Which are interacting galaxies?

[mental4astro (Alexander)]

Paddy came up with the interacting galaxy group NGC 6782 et al as a nomination for this August Obs. Challenge.

This got me to thinking about which are the other observable interacting galaxy complexes for the Southern sky.

I know of NGC 6769 group, The Devil's Mask, and the Antennae Galaxies, NGC 4038/9.

Can someone guide me to other observable complexes?

[renormalised (Carl)]

If you want I'll post you Arp's Atlas. I have a copy

Or, go here and scroll down to the interacting galaxies section.

[bojan]

Arp Atlas of Galaxies:
http://nedwww.ipac.caltech.edu/level..._contents.html

[mental4astro (Alexander)]

I had heard about the Arp Atlas by name only. Didn't know what it was about! Boy, what a reasource.

Thanks for that. Should keep me busy for a couple of nights, .

[bojan]

PDF version:
http://nedwww.ipac.caltech.edu/level5/Arp/paper.pdf

However, it contains links to higher resolution images.. they will not work if this doc is opened as pdf on your machine.

[renormalised (Carl)]

Here's something else which will grab your interest

http://willbell.com/HANDBOOK/arp.htm

[Paddy (Patrick)]

Originally Posted by mental4astro

I had heard about the Arp Atlas by name only. Didn't know what it was about! Boy, what a reasource.

Thanks for that. Should keep me busy for a couple of nights, .

Not a bad review of it at http://www.iceinspace.com.au/46-570-0-0-1-0.html

Just looking at my copy, some of the Arps that would be viewable now would be

Arp 254 - NGC 5917 + companion in Libra (very faint at 14.5 and you'd want dark skies and a big scope)
Arp 261 - MCG 2-38-16 + 17 in Libra - mag 13.4
Arp 271 NGC5426+7 in Virgo mag 12.0
Arp 93 NGC 7284 +5 in Pisces Austrinus mag 12.9
Arp 14 NGC 7314 mag 10 Pisces Austrinus - not interacting, but "peculiar" - spiral with detached segments is Arp's note

so none of them very bright. The problem is that Arp viewed only from the Northern hemisphere so his catalogue misses out on a lot of the galaxy chains and interacting galaxies that we have.

[renormalised (Carl)]

There's an interesting project... since Arp did all of his observing of mostly Nth Hemisphere objects, why not do a survey of the Sth Hemisphere peculiar and interacting galaxies. Call it the "Harp Catalogue"

[Paddy (Patrick)]

Originally Posted by renormalised

There's an interesting project... since Arp did all of his observing of mostly Nth Hemisphere objects, why not do a survey of the Sth Hemisphere peculiar and interacting galaxies. Call it the "Harp Catalogue"

Very good idea.

I should point out for those that haven't looked at Arp's atlas that there are a lot of observable southern Arps, they are just not above the horizon much at present.

[ngcles]

Hi Alexander & All,

There are probably in the order of four dozen galaxies -- if not more that are observable in 45cm from Halton Arp's list given a true dark sky. Only a few of them are truly inviting telescopic treats mind you, but deep sky observing is done as much with the mind's-eye as with the eye. If you have an appreciation of the nature of what you are looking at, it adds a great deal to those tiny little dots of mist.

Once you have finished those off, you could then try yourself out on Benjamin Markarian's catalogue of compact, optically bright galaxies that include starbursts and active galactic nuclei and many other galaxies with odd morphologies, many of which are also peculiar, interacting or ... weird in one way or another.


Best,

Les D

[renormalised (Carl)]

Thanks for reminding me of Markarian's Catalogue, Les. Good deal more to see in that particular catalogue, and quite a few really interesting galaxies