by Ann » Wed May 16, 2018 2:06 pm
edgardine wrote: ↑Wed May 16, 2018 12:21 pm
Ann wrote: ↑Wed May 16, 2018 8:55 am
edgardine wrote: ↑Wed May 16, 2018 6:16 am
So glad about gaia's data.
However, one of the sentences seems to be outdated information "The LMC [...] is a spiral galaxy that has been distorted by encounters with the greater Milky Way Galaxy and the lesser Small Magellanic Cloud."
Recently, I read some articles about the past encounters of Andromeda, in which they said that the LMC has been distorted then.
I may be wrong
This
Wikipedia article about the Hubble sequence identifies the Large Magellanic Cloud as an irregular galaxy. However, I think it could be argued that the LMC might also be classified as an SBd galaxy:
Sd (SBd) – very loosely wound, fragmentary arms; most of the luminosity is in the arms and not the bulge.
If you take a look at
this picture of the Large Magellanic cloud, you might perhaps agree that the scattered regions of star formation surrounding the bar of the LMC do show some slight simiarities to spiral arms.
Ann
Thank you for your answer, Ann. (I really appreciate your work on color, there are so many inconsistencies about it)
You're welcome!
English is not my native language,
It's not mine, either. I wonder how many gaffes I've made here over the years.
Well, personally I wouldn't think that M31 has affected the Magellanic Clouds all that much. The Astrophysical Journal doesn't seem to think so, either.
The Astrophysical Journal wrote:
For a range of LMC proper motions approximately 3σ higher than the mean and total Local Group mass >3.5 × 1012 M ☉, M31 can provide a significant torque to the LMC orbit. However,
if the LMC is bound to the MW, then
M31 is found to have negligible effect on its motion, and the origin of the high angular momentum of the system remains a puzzle.
So is the Large Magellanic Cloud bound to the Milky Way? Are both Magellanic Clouds bound to the Milky Way? I'd say that, yes, that seems highly probable.
Take a look at the map at left. It shows the Local Group of galaxies. The Milky Way is in the middle of the map. Can you see the two little elongated white things to the left of it? I'd say that those little objects are the Magellanic Clouds. Note how close they are to the Milky Way! Note that the Andromeda galaxy is much farther away. It, too, has two little objects right next to itself. Those two little satellite galaxies are M32 and NGC 205.
I
believe that it is fairly generally accepted that the Magellanic Clouds have been interacting with each other for quite some time, perhaps for a billion years or so. Most likely, though, the Magellanic Clouds were not snared by the gravity of the Milky Way until more recently.
So I'd say that the distorted shape of the LMC is mostly due to interactions with the LMC, but it is also caused by the mighty pull of the Milky Way.
Ann
[quote=edgardine post_id=282515 time=1526473262 user_id=144310]
[quote=Ann post_id=282506 time=1526460919 user_id=129702]
[quote=edgardine post_id=282503 time=1526451366 user_id=144310]
So glad about gaia's data.
However, one of the sentences seems to be outdated information "The LMC [...] is a spiral galaxy that has been distorted by encounters with the greater Milky Way Galaxy and the lesser Small Magellanic Cloud."
Recently, I read some articles about the past encounters of Andromeda, in which they said that the LMC has been distorted then.
I may be wrong
[/quote]
This [url=https://en.wikipedia.org/wiki/Hubble_sequence]Wikipedia article about the Hubble sequence[/url] identifies the Large Magellanic Cloud as an irregular galaxy. However, I think it could be argued that the LMC might also be classified as an SBd galaxy:
[quote]Sd (SBd) – very loosely wound, fragmentary arms; most of the luminosity is in the arms and not the bulge.[/quote]
If you take a look at [url=https://apod.nasa.gov/apod/ap080409.html]this picture of the Large Magellanic cloud[/url], you might perhaps agree that the scattered regions of star formation surrounding the bar of the LMC do show some slight simiarities to spiral arms.
Ann
[/quote]
Thank you for your answer, Ann. (I really appreciate your work on color, there are so many inconsistencies about it)[/quote]
You're welcome! :D
[quote]English is not my native language,[/quote]
It's not mine, either. I wonder how many gaffes I've made here over the years. :wink:
[quote] I probably did not express myself clearly. What I consider potentially outdated is that the LMC has been distorted by the Milky Way rather than by Andromeda.
I read a recent article about it, but I can not retrieve it.
Here are two
http://iopscience.iop.org/article/10.1088/0004-637X/700/2/924/meta
https://arxiv.org/abs/1010.2748
[/quote]
Well, personally I wouldn't think that M31 has affected the Magellanic Clouds all that much. The Astrophysical Journal doesn't seem to think so, either.
[quote][url=http://iopscience.iop.org/article/10.1088/0004-637X/700/2/924/meta]The Astrophysical Journal[/url] wrote:
For a range of LMC proper motions approximately 3σ higher than the mean and total Local Group mass >3.5 × 1012 M ☉, M31 can provide a significant torque to the LMC orbit. However,[b][size=120][color=#4040FF] if the LMC is bound to the MW[/color][/size][/b], then [b][size=120][color=#BF4000]M31 is found to have negligible effect on its motion[/color][/size][/b], and the origin of the high angular momentum of the system remains a puzzle.[/quote]
[float=left][img2]http://www.atlasoftheuniverse.com/localgrp.gif[/img2][c][size=85]The Local Group of galaxies. Illustration:
http://www.atlasoftheuniverse.com/localgr.html[/size][/c][/float]So is the Large Magellanic Cloud bound to the Milky Way? Are both Magellanic Clouds bound to the Milky Way? I'd say that, yes, that seems highly probable.
Take a look at the map at left. It shows the Local Group of galaxies. The Milky Way is in the middle of the map. Can you see the two little elongated white things to the left of it? I'd say that those little objects are the Magellanic Clouds. Note how close they are to the Milky Way! Note that the Andromeda galaxy is much farther away. It, too, has two little objects right next to itself. Those two little satellite galaxies are M32 and NGC 205.
I [b][i]believe[/i][/b] that it is fairly generally accepted that the Magellanic Clouds have been interacting with each other for quite some time, perhaps for a billion years or so. Most likely, though, the Magellanic Clouds were not snared by the gravity of the Milky Way until more recently.
So I'd say that the distorted shape of the LMC is mostly due to interactions with the LMC, but it is also caused by the mighty pull of the Milky Way.
Ann