by Ann » Mon Jun 24, 2013 12:10 pm
starsurfer wrote:The world has become a happier place today!!
![Very Happy :D](./images/smilies/icon_biggrin.gif)
I'm so happy I could hug Ann!
![Wink :wink:](./images/smilies/icon_wink.gif)
Hugs right back at you, starsurfer!
![Very Happy :D](./images/smilies/icon_biggrin.gif)
It's great to see a galaxy here, isn't it?
As for why the elliptical galaxy in this interacting pair is so undisturbed, the best explanation is probably that at least some elliptical galaxies are quite compact. Others, however, do have large halos and shells which are remnants of previous mergers. Check out, for example,
this image of lenticular galaxy NGC 1316. Merging with a smaller (probably spiral) galaxy has adorned this galaxy with dust lanes in its large bulge and a pair of large broad ghostly "arms".
Check out, too,
this picture of the Hercules cluster of galaxies by Adam Block. Note the pair of interacting galaxies at one o'clock. The galaxies have thrown out arm-like ghostly broad tidal tails.
And of course, the elliptical component of
everyone's favorite interacting pair, M51 and NGC 5195, also shows very clear signs of interruption. But even here, the tidal feature of NGC 5195 are so much fainter than the splendid arms of M51.
Large elliptical galaxies typically show a set of nesting "shells" as remnants of previous mergers.
Here you can see the shells of NGC 5128.
Ann
[quote="starsurfer"]The world has become a happier place today!! :D I'm so happy I could hug Ann! :wink:[/quote]
Hugs right back at you, starsurfer! :D It's great to see a galaxy here, isn't it? :D
As for why the elliptical galaxy in this interacting pair is so undisturbed, the best explanation is probably that at least some elliptical galaxies are quite compact. Others, however, do have large halos and shells which are remnants of previous mergers. Check out, for example, [url=http://asterisk.apod.com/viewtopic.php?p=201503#p201503]this image of lenticular galaxy NGC 1316[/url]. Merging with a smaller (probably spiral) galaxy has adorned this galaxy with dust lanes in its large bulge and a pair of large broad ghostly "arms".
Check out, too, [url=http://www.caelumobservatory.com/mlsc/n6050.jpg]this picture of the Hercules cluster of galaxies[/url] by Adam Block. Note the pair of interacting galaxies at one o'clock. The galaxies have thrown out arm-like ghostly broad tidal tails.
And of course, the elliptical component of [url=http://images.astronet.ru/pubd/2010/06/25/0001245678/M51_peris.jpg]everyone's favorite interacting pair, M51 and NGC 5195[/url], also shows very clear signs of interruption. But even here, the tidal feature of NGC 5195 are so much fainter than the splendid arms of M51.
Large elliptical galaxies typically show a set of nesting "shells" as remnants of previous mergers. [url=http://www.astro.virginia.edu/class/whittle/astr553/Topic07/t7_shell_n5128.jpg]Here you can see the shells of NGC 5128[/url].
Ann