Trying to understand the differences between distant & local galaxies

[Cerenkov]

Hello.

The recent discovery of the galaxy SPT0418-47 has piqued my interest.

https://www.almaobservatory.org/en/images/reconstructed-view-of-spt0418-47/

https://en.wikipedia.org/wiki/SPT0418-47

https://www.eso.org/public/archives/releases/sciencepapers/eso2013/eso2013a.pdf

It's my current understanding that galaxies at this red shift are expected to display very different characteristics (star formation rates, rotation, metallicity, size, etc.) to the mature and highly-evolved galaxies in the local universe. But, it appears that certain characteristics of SPT0418-47 seem to buck this expectation.

It occurs to me that I need to discover more about how galaxies are characterised. Then, knowing this I could look at the characteristics of local galaxies and compare them to those distant ones with a better understanding.

So, this prompts me to ask the following questions.

1.
Is finding out about how galaxies are characterised a good first step in understanding the differences between distant, early galaxies and nearby, evolved ones in the local universe?

2.
If so, could I please be directed to some Basic Level resources (links, websites, blogs, etc.) that will help me achieve this?

3.
If not, could I please be guided to a better option?

4.
In the context of this topic, does the word 'Local' refer to the Local Group of galaxies, to the Virgo or Laniakea Superclusters or to a measurement relating to the redshift (z) ?

Any help given would be very much appreciated.

With thanks,

Cerenkov.

 

[AndrewWayneHarville]

Hope it helps but I am not very inteliggent on this matter

 

[Keith_McClary]

I found this course:
http://faculty.washington.edu/ivezic/t_astr323.html
Also, our Free Physics Books list.

 

[davenn]

View attachment 276676 Hope it helps but I am not very inteliggent on this matter

That has nothing to do with local and distant galaxies. It's referring to our Milky Way galaxy

 

[Cerenkov]

Many thanks for the help folks.

I thought this thread had died stillborn.

Looks like I was wrong.

Thanks again.

Cerenkov.

 

[snorkack]

Hello.

The recent discovery of the galaxy SPT0418-47 has piqued my interest.

https://www.almaobservatory.org/en/images/reconstructed-view-of-spt0418-47/

https://en.wikipedia.org/wiki/SPT0418-47

https://www.eso.org/public/archives/releases/sciencepapers/eso2013/eso2013a.pdf

It's my current understanding that galaxies at this red shift are expected to display very different characteristics (star formation rates, rotation, metallicity, size, etc.) to the mature and highly-evolved galaxies in the local universe. But, it appears that certain characteristics of SPT0418-47 seem to buck this expectation.

It occurs to me that I need to discover more about how galaxies are characterised. Then, knowing this I could look at the characteristics of local galaxies and compare them to those distant ones with a better understanding.

So, this prompts me to ask the following questions.

1.
Is finding out about how galaxies are characterised a good first step in understanding the differences between distant, early galaxies and nearby, evolved ones in the local universe?

2.
If so, could I please be directed to some Basic Level resources (links, websites, blogs, etc.) that will help me achieve this?

3.
If not, could I please be guided to a better option?

1) is correct, but the link offered for 2) is not a very good one, yet I don´ t know a better one.

The classification of nearby galaxies is basically into "elliptical" and "spiral" galaxies, with intermediate group of "lenticular"... plus "irregular" galaxies.
Irregular galaxies are common even in local universe - just look up for the Magellanic Clouds. Yet the link only briefly mentions irregular galaxies, and discusses elliptical and spiral galaxies at length.

The problem with SPT0418-47 refers to a guess that young world should have had only irregular galaxies, and no elliptic or spiral galaxies.

4.
In the context of this topic, does the word 'Local' refer to the Local Group of galaxies, to the Virgo or Laniakea Superclusters or to a measurement relating to the redshift (z) ?

To redshift.