APOD: Sideways Galaxy NGC 3628 (2011 Mar 16)

[APOD Robot]

Sideways Galaxy NGC 3628

Explanation: Dark dust lanes cut across the middle of this gorgeous island universe, a strong hint that NGC 3628 is a spiral galaxy seen sideways. About 35 million light-years away in the northern springtime constellation Leo, NGC 3628 bears the distinction of being the only member of the well known Leo triplet of galaxies not in Charles Messier's famous catalog. Otherwise similar in size to our Milky Way Galaxy, the disk of NGC 3628 is clearly seen to fan out near the edges. A faint arm of material extends to the upper left. The distorted shape and faint tidal tail suggest that NGC 3628 is interacting gravitationally with the other spiral galaxies in the Leo triplet, M66 and M65. The dusty disk of NGC 3628 is also dotted with the telltale reddish hues of star-forming regions in this sharp telescopic view. Explore the full resolution version here.

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[Beyond]

I wish i could look that thin sideways

[garry]

If this galaxy is interacting with other galaxies to give the twisted arms, why is it that similar galaxies that are as close, do not exhibit the same characteristics? Could it be that there are other forces at work and we just have not found or understood them yet?

[Stevie wonders...]

Why do they call them 'island universes"? Is this an artifact from a time when our understanding of the universe was less expansive than it is today?

[orin stepanek]

Why do they call them 'island universes"? Is this an artifact from a time when our understanding of the universe was less expansive than it is today?

It is like an island in the universe.

Notice how this galaxy is as wide on the edges as it is in the center? Most galaxies seem to be tapered on the edges making this galaxy unique in my opinion.

[NoelC]

From deeper images it's clear that this is a galaxy that's been recently (in galactic terms) disturbed by interaction with another galaxy - possibly they merged. The tidal tail (stream of stars) that runs to the upper left is not that easily visible in this image.

It strikes me that it would be quite a lonely thing to be on a planet in a star out in such a tidal tail, but what a view of the nearby galaxies!

-Noel

[Zachary Taylor Jackson]

Is there any evidence of tidal distortion in our own Milky Way?

[starwolf69]

Is there any evidence of tidal distortion in our own Milky Way?

I'm sure any 'large body' in the Local Group, such as the Andromeda Galaxy, has some type significant effect on MW.

[bystander]

Why do they call them 'island universes"? Is this an artifact from a time when our understanding of the universe was less expansive than it is today?

Yes, it was once thought that the Milky Way was the Universe. In the mid 18th century, Thomas Wright speculated that some of the nebulae visible might be separate Milky Ways (or galaxies) and Immanuel Kant coined the term "island universe" to describe them. It wasn't until the early 20th century and the "Great Debate" that it became accepted that our Milky Way was, in fact, just one of many island universes.

http://en.wikipedia.org/wiki/Galaxy#Dis ... er_nebulae

[Zachary Taylor Jackson]

Is there any evidence of tidal distortion in our own Milky Way?

I'm sure any 'large body' in the Local Group, such as the Andromeda Galaxy, has some type significant effect on MW.

It does seem likely, but my question was "is there any proof?" There are star streams from dwarf galaxies known in and near the Milky Way, but not a true tidal feature as far as I have heard.

[Chris Peterson]

It does seem likely, but my question was "is there any proof?" There are star streams from dwarf galaxies known in and near the Milky Way, but not a true tidal feature as far as I have heard.

Science doesn't ask for proof, it asks for evidence. I don't think there is any observational evidence of tidal distortion of the Milky Way by Andromeda or other nearby galaxies. But I also think the reality of such distortion is much greater than just "it does seem likely". In fact, it is certain unless our entire understanding of gravity is incorrect, which is very unlikely.

[bkinmonth]

If I see the phrase "gorgeous island universe" one more time, I might just die. (and no, I won't be dying happy...)

[NoelC]

Okay, it's a homely island universe then.

-Noel