Beaut of a jellyfish candidate


Callum and Co would love this one - nice spot.

The blue wanna-be spiral-2 is MCG -01-07-003 Z=0.00764
The elliptical just SW is 6dFGS gJ022245.7-035823 Z=0.09483
Those are spectroscopic so the elliptical is well into the background

So if the blue is the jellyfish, the wind is blowing out in all 360 degrees?
Is that a thing?

I think it may be that we are looking at a young LSB irregular with spiral2 ambitions
It has a nice little core started but it needs a lot more mass to spin up a disk

The blue clumps will move toward the mass in the center - speeding up as it grows
Come back in a few eons and you’ll probably see a nice spiral-2

Or, maybe my hat is sideways and it is an ordinary jellyyfish

I expect they’re not all emanating from the obvious nucleus, but from the faint but large disk structure, and all in the same direction (mostly radially)

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My guess is spiral arms that have been “unwound” (to steal the Zooniverse phrasing). The ram-pressure is mostly just enough to strip some material but if you have enough of this apparent pressure (and combined with loosely held arms) the arms can unwind. The diffuseness here seems to suggest that could very much be what is happening.

EDIT: apparently it’s a galaxy group? I might have to completely rewrite the above…

Side note: it would seem to me that to “unwind” spiral arms perfectly you would require the apparent vector of the pressure to make a fairly specific angle with the angle of the spiral - would this be correct?

Re the vector needed for unwinding: Yes, wind from a certain vector will produce a particular unwinding

I have always wondered why we don’t look for arm compression or winding if a galaxy is facing a stiff wind

Re unwinding in all 360 degrees: Maybe a swirling face-on wind (which just sounds too specific to be likely) or just a strong face-on push - but you’d think that would just move the galaxy

So I am dubious…

The FFJG workflow assumes asymmetry for the unwinding question

Makes sense because if all unwound symmetrically how would the classifier be able to distinguish between looseness of galaxy arms and unwinding of them?

Sorry, what is FFJG? My scientific lingo isn’t always on point

Fishing for Jellyfish Galaxies - its a Zooniverse project

The Zooniverse Jellyfish project Fishing For Jellyfish Galaxies

My bad, I thought I was writing over there for a moment

If you have ever done citizen science like Galaxy Zoo you are familiar with the idea of choice based work flow
For example “Do some of the spiral arms appear to be extending, or unwinding, compared to others? (Do the spiral arms differ in length or shape?)”
And the next question depends on the answer

That whole question tree is called the workflow of the project

And I hope that my comment now makes sense to you

NASA released this jellyfish Hubble image last month

Ah I see - didn’t know the acronym despite the hours spent on it :slight_smile:

Yes very much, thank you. The hours of button clicking have come flooding back.