M51 Cosmic Whirlpool (APOD 11 Nov 2006)

orin stepanek · Post by **orin stepanek** » Sun Nov 12, 2006 7:34 pm

http://antwrp.gsfc.nasa.gov/apod/ap061111.html

Are these galaxies really interacting? It appears that the smaller galaxy is actually in the background and quite a bit further away. I don't see any real disruptions of either galaxy!

Orin

harry · Post by **harry** » Mon Nov 13, 2006 8:53 am

Hello Orin

Maybe this will help

http://www.seds.org/messier/more/m051gr.html

They are interacting.

It maybe my eyes, but I think the external spiral arms are pulled out.

Nereid · Post by **Nereid** » Mon Nov 13, 2006 12:24 pm

For those interested, this Hubblesite page contains details of the orientation, location (in the sky), and scale of the APOD (as well as other information).

orin stepanek · Post by **orin stepanek** » Tue Nov 14, 2006 2:16 am

Explain to me how they are interacting. I see no visual effect as you normally would. The spiral that covers the background galaxy seem to remain intact. The background galaxy seems to be intact also.

Orin

harry · Post by **harry** » Tue Nov 14, 2006 8:45 am

Hello Orin

When there is a close encounter the arms start to spread as we see it on the top right. Not only that the arms if you look very close are coming out. Top left and centre right. Just like the tides on earth with the moon.

orin stepanek · Post by **orin stepanek** » Tue Nov 14, 2006 2:20 pm

harry wrote:Hello Orin

When there is a close encounter the arms start to spread as we see it on the top right. Not only that the arms if you look very close are coming out. Top left and centre right. Just like the tides on earth with the moon.

That may not necessarily be the case! Not all galaxies have their trailing arms tight to the galaxy!

http://antwrp.gsfc.nasa.gov/apod/ap030413.html

http://160.114.99.91/astrojan/Ngc/ngc0613.gif

http://www.ngcic.org/dss/n/1/n1723.jpg

http://160.114.99.91/astrojan/Ngc/ngc3347.jpg

http://www.aao.gov.au/images/captions/aat098.html

Orin

Texchanchan · Post by **Texchanchan** » Tue Nov 14, 2006 10:40 pm

The big galaxy with the pink hotspots - Rosenkrantz (rose garland).
The small, yellow, bright one - Guildenstern (gold star)

harry · Post by **harry** » Wed Nov 15, 2006 6:22 am

Hello Orin

You said

That may not necessarily be the case! Not all galaxies have their trailing arms tight to the galaxy!

Thats correct, the images that you chose have their arms out, they have close encounters and collisions.

The image

http://antwrp.gsfc.nasa.gov/apod/ap061111.html
Has not so close encounter and therfore the arms are close, apart from some areas extending .

orin stepanek · Post by **orin stepanek** » Wed Nov 15, 2006 3:18 pm

harry wrote:Hello Orin

You said

That may not necessarily be the case! Not all galaxies have their trailing arms tight to the galaxy!
Thats correct, the images that you chose have their arms out, they have close encounters and collisions.

The image

http://antwrp.gsfc.nasa.gov/apod/ap061111.html
Has not so close encounter and therfore the arms are close, apart from some areas extending .

Than why is the far arm extending?

Orin

harry · Post by **harry** » Fri Nov 17, 2006 7:01 am

Hello Orin

Because of the close encounter with the other galaxy.

orin stepanek · Post by **orin stepanek** » Fri Nov 17, 2006 5:07 pm

Harry doesn't convince me!

Maybe he is right but I believe the arms stretched out don't have anything to do with the background galaxy! at last the far spiral arm. It is possible of course; but I need a better explanation.

Orin

BMAONE23 · Post by **BMAONE23** » Fri Nov 17, 2006 5:31 pm

http://coolcosmos.ipac.caltech.edu/imag ... arged.html
Here is a good view from Spitzer. It shows what appears to be interaction in the form of the mis-shaping of the spiral arm closest to the other galaxy.

orin stepanek · Post by **orin stepanek** » Fri Nov 17, 2006 5:42 pm

BMAONE23 wrote:http://coolcosmos.ipac.caltech.edu/imag ... arged.html
Here is a good view from Spitzer. It shows what appears to be interaction in the form of the mis-shaping of the spiral arm closest to the other galaxy.

I can see it there! That is a very good view. Thanks BMAONE23 And thank you also Harry!

Orin

harry · Post by **harry** » Fri Nov 17, 2006 10:30 pm

Hello Orin

Anytime mate.

I would assume that the close encounter would pull the arms out.

Another possibility is could the arms fling out because of the spin of the galaxy and the direction of movement.

orin stepanek · Post by **orin stepanek** » Sat Nov 18, 2006 3:11 pm

harry wrote:Hello Orin

Anytime mate.

I would assume that the close encounter would pull the arms out.

Another possibility is could the arms fling out because of the spin of the galaxy and the direction of movement.

Harry! After watching a lot of interacting galaxies really stretch out; I'm thinking that maybe they slow down the spin causing them to unwind so to speak.

Orin

BMAONE23 · Post by **BMAONE23** » Thu Dec 07, 2006 10:07 pm

Here is another great image of M51 from Spitzer http://www.space.com/php/multimedia/ima ... %20enlarge.

Starship Asterisk*

M51 Cosmic Whirlpool (APOD 11 Nov 2006)

M51 Cosmic Whirlpool (APOD 11 Nov 2006)

M51 Rosenkrantz and Guildenstern