Author Topic: The Shape of the Galaxy Project  (Read 6827 times)

aardvak

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The Shape of the Galaxy Project
« on: July 18, 2011, 01:38:47 pm »
This is the first post of many, I will undertake throughout this summer, reporting daily on what I have found. The project's main goal is to classify our own galaxy, by using the properties of similar galaxies to determine the structure of ours. We will try to find accurate clones of our galaxy which might enable us to finally see where we live. Today we started by researching commonly held beliefs in the science world. We found two theorems which sound very realistic (http://www.atlasoftheuniverse.com/milkyway.html and http://www.guardian.co.uk/science/punctuated-equilibrium/2011/jul/05/2). They show our galaxy to have two main spiral arms which broaden into more, sub-arms. Both also show the bar-like centre of our galaxy and they provide possible clones which we could use. Both arguments are supported by numerous claims and evidences, but this project has got goals to try and find better clones. To do this we will study the number of spiral arms, size of the central bulge and bar classifications to hopefully find a perfect match. By the end of this summer we hope to have some solid evidence to support any claims we might have. To finally present our findings we will use a programme to make a graph showing these variables against those of the Milky Way, which will hopefully show at least one galaxy to be an almost perfect clone to our own environment.

Aardvak

aardvak

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The Shape of the Galaxy Project - Day 2
« Reply #1 on: July 19, 2011, 12:37:07 pm »
Here is the second day's findings I am posting. Today we outlined how we will classify the properties of many galaxies, thus narrowing the list of possible matches. The criteria we will be working with is as follows: Mass of galaxy, Star formation rate of galaxy, Colour of galaxy, properties of galaxy (such as whether there is a central bar present and how many spiral arms it has), luminosities of galaxy and environments of galaxy. Using the mass of 1.4x1042kg as a mass for the galaxy, I will find a broad variety of similar galaxies with which I can test the other fields on. Secondly, whilst reading articles online, I came across a piece which showed how the Galaxy is not an ordinary one (www.physorg.com/news/2011-05-milky-mid-life-crisis.html). It is not a highly productive blue galaxy, which has a high star formation rate, and it isn't a red sequence galaxy, which has a low star formation rate. It is part of a very rare group of galaxies called the green valley group. This means that our Galaxy has a star formation rate which is more a trickle than a flood or a drought. The graph on the diagram shows how uncommon this galaxy is compared to it's neighbours, also it shows that there could be other galaxies with either a very large reading for their luminosities or a very small one, as the graph shows no boundaries for the green valley galaxies. This could either be down to the fact that there is no known edge to this part of the scale, or it could be down to the fact that the scale is incomplete in some way. Either way shows us that our Galaxy is very special and rare. If it is discovered that our galaxy does indeed have four spiral arms instead of two, and we do fit in this green valley space, then it could may well be that our galaxy is one of a very rare breed, more of which will become apparent in later posts.

Aardvak

aardvak

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The Shape of the Galaxy Project - Day 3
« Reply #2 on: July 20, 2011, 10:32:06 am »
Tomorrow we will have compiled a data sheet with many of the galaxies classified by people in Galaxy Zoo. From this we will be able to start to make real headway in the project as until now we have just been doing the research behind the project. This will allow us to start narrowing the search down. At the end of the project we will compile a table of what currently is the thought of what the galaxy looks like and compare it to between five and ten candidates for clone galaxies. Then a graph will be plotted and all the galaxies will be superimposed upon a graph of our galaxies table and hopefully we will have a match. First however we need the table of data, which comes tomorrow. Today's work, will mostly involve getting used to the software we will be using to plot the graphs and tables, called 'IDL'. Unfortunately for me, it means learning a whole new language...

Aardvak

zookeeperChris

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Re: The Shape of the Galaxy Project
« Reply #3 on: July 21, 2011, 12:13:56 pm »
Hiya

Thought you might be interested in the paper that produced the image that's cited in the Guardian article you link to above - it's here.

We also mention a comparison with the Milky Way in one of Kevin's papers, here.

Chris

aardvak

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Re: The Shape of the Galaxy Project
« Reply #4 on: July 21, 2011, 12:41:44 pm »
unfortunately this post will be very short as the table has not been got due to unforeseen circumstances and so progress has been slow today. The main progress of today was learning more about the computing programme IDL. Most of it remains a mystery to me but it remains a challenge I hope to conquer. Also more background reading was used today to ensure I have as much required knowledge as possible, for when the meat of the project starts going.

Aardvak

EigenState

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Re: The Shape of the Galaxy Project
« Reply #5 on: July 21, 2011, 08:35:42 pm »
Greetings,

First of all, welcome to the Zoo aardvak.

Now some questions regarding your research and its objectives.  In what way is the rather limited observational data of the Milky Way sufficiently comprehensive to support substantive, objective, and quantitative comparisons to the structure of other galaxies?  What is the physical significance of finding what you refer to as a "clone" of the Milky Way?  Lastly, why provide non-substantive daily updates rather than present the results of your investigations once they are complete?

Best regards,
EigenState

aardvak

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Re: The Shape of the Galaxy Project
« Reply #6 on: July 22, 2011, 08:45:36 am »
I will post findings later today, specifically for the project, this is just a message clearing up any ambiguities I may have introduced. Firstly, we will be studying other galaxies similar to the Milky Way and from the limited data we have on our Galaxy, will try to find another galaxy which matches. For example; if we know the Milky Way has diameter x and mass y, we will look for galaxies with diameter x and mass y, discarding galaxies with mass z. From list shortened list we will then discount galaxies which don't match up with the Milky Way's star formation rate. When we have input all the known data from the Milky Way, we will hopefully have a unique group of galaxies similar to the Milky Way, we can then see data that we don't know about the Milky Way and find a rough estimate from the other Galaxies which share the properties we do know. The significance of this is still a mystery, to me at least, others may have a reason for doing this scientifically, but if we take the example of electricity, it was first thought that it was just a 'pretty' exhibit at a science fair with no uses. Now electricity is a crucial part of modern culture, as i wouldn't be able to communicate with you without it. Thus I believe there must be a use for finding the structure and formation of the Galaxy even if we don't know it at this point in time. Thirdly, the reason for writing this 'journal' of my day's work is not only to document it for a later date, I can also show it to the science world, which people hopefully will take an interest in and provoke interesting discussions. It also is a requirement of the current course I am doing as part of my A level Physics course. As I say, results about today's project advancements will follow later in the day.

Aardvak




aardvak

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Re: The Shape of the Galaxy Project
« Reply #7 on: July 22, 2011, 01:29:14 pm »
Today has been another day of expecting tables, but alas no table, no one's fault of course as everyone is very busy here, so today i have entertained myself in finding out about the formation of galaxies and meandering through the backwaters of wikipedia. Many interesting things have been found but sadly little to do with this project. Never mind, fun has been had. Minds have been expanded. Tea has been drunk. So we now have the energy to survive the weekend to come back with a vengeance, and a guaranteed table on Monday, ready to be plotted. This i look forward to greatly having new data to work with. This will I'm sure test me greatly with IDL software but I'll endeavour to make it work to get a nice set of results.

Aardvak 

EigenState

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Re: The Shape of the Galaxy Project
« Reply #8 on: July 22, 2011, 01:56:11 pm »
Greetings,

Thirdly, the reason for writing this 'journal' of my day's work is not only to document it for a later date ...

Excellent practice.  It is called a research notebook--ink on paper in a hard bound notebook--that constitutes the historical record.

Given that this is related directly to your school work, I shall not comment further.

Best regards,
EigenState

aardvak

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Re: The Shape of the Galaxy Project
« Reply #9 on: July 25, 2011, 12:02:17 pm »
Well its Monday afternoon and the table of data is proving to be confusing. More background reading on IDL, plotting 2D and 3D graphs, still a little confusing, but I'm getting there. Throughout the last few days I have mainly been doing research and reading around the subject. For those of you who are reading this more than others, I think that the more interesting parts of this project will come later when I have a greater hold of the programming and the data. I will try to keep up this thread to keep everyone informed about what is going on but I'm afraid they will be the same sort of detail. On a less relevant topic today I have found a picture of what is thought to be the galactic central point. Not sure how reliable this picture is but wikipedia tends to be fairly good, here is the website, http://en.wikipedia.org/wiki/Galaxy, the picture is on the right hand side and about a quarter of the way down the page. Not really much more for me to talk about today so I'm going to say bye bye for today, and I hope have more interesting data for tomorrow.

Aardvak

klmasters

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Re: The Shape of the Galaxy Project
« Reply #10 on: July 27, 2011, 09:05:13 am »
I'm a bit slow noticing this thread (in fact didn't notice until Aardvark pointed it out to me in an email this morning), but I wanted to jump in and introduce Aardvark who is a local A-level student working with me in Portsmouth this summer on a project comparing the properties of galaxies with similar morphologies to the Milky Way (ie. 2 or 4 arms depending on which observations you believe and a bar) with the properties of Milky Way itself. As he has picked an anonymous username I will stick with referring him in that way on this forum.

 I'm the guilty culprit who was too slow and busy to get him the table of GZ2 classifications he needed last week (in my defense he's been much quicker at picking up using Linux or IDL than I expected, and I was unexpectedly busy last Friday!).

 I also encouraged him to post a weblog of his research here, so please be nice in your comments (as I'm sure you will be!).

 We do also plan to together write a blog post with the final results later in the summer.

 Aardvark will be with us in Portsmouth over the next few weeks, although this morning he told me in his email he's a bit under the weather so is working from home.

elizabeth

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Re: The Shape of the Galaxy Project
« Reply #11 on: July 28, 2011, 06:47:02 pm »
I'm a bit slow noticing this thread (in fact didn't notice until Aardvark pointed it out to me in an email this morning), but I wanted to jump in and introduce Aardvark who is a local A-level student working with me in Portsmouth this summer on a project comparing the properties of galaxies with similar morphologies to the Milky Way (ie. 2 or 4 arms depending on which observations you believe and a bar) with the properties of Milky Way itself. As he has picked an anonymous username I will stick with referring him in that way on this forum.

 I'm the guilty culprit who was too slow and busy to get him the table of GZ2 classifications he needed last week (in my defense he's been much quicker at picking up using Linux or IDL than I expected, and I was unexpectedly busy last Friday!).

 I also encouraged him to post a weblog of his research here, so please be nice in your comments (as I'm sure you will be!).

 We do also plan to together write a blog post with the final results later in the summer.

 Aardvark will be with us in Portsmouth over the next few weeks, although this morning he told me in his email he's a bit under the weather so is working from home.
:D I for one was wondering. Thanks for the info.

Alice

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Re: The Shape of the Galaxy Project
« Reply #12 on: July 29, 2011, 02:50:11 pm »
Welcome to the zoo Aardvark! Get well soon and enjoy working at Portsmouth. :)

aardvak

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Re: The Shape of the Galaxy Project
« Reply #13 on: August 03, 2011, 09:24:00 am »
Sorry for the long delay, in messages but here I am. Yesterday I got into the document on IDL which I then plotted to find out it was a picture of four parts. The first was a large circular cluster of points in the very center. This would be a normal graph if it finished there, but there were fthree other cigar-shaped bars of points, one next to the main cluster, one down in the bottom left of the graph and one in the top left. This obviously shows that there are multiple different classes of data here with the largest also being the most consistent. This data having come late yesterday means there is not much more i can observe at this point but im sure there will be more to come. In more vague areas I am still reading much around the subject and am finding more and more that candidates for clones of our galaxy mainly have flaws in them. For example the galaxy i explained about in my first post is very similar to our galaxy in all respects but it is vastly more massive. So therefore it's different. And not a clone.

Aardvak

klmasters

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Re: The Shape of the Galaxy Project
« Reply #14 on: August 04, 2011, 11:48:23 am »
What Aadrvark is describing is the sky distribution of the galaxies in the Sloan Digital Sky Survey which are used by Galaxy Zoo. He could see the main sample (the big cluster in the middle) plus the famous Stripe 82 which is the main "cigar-shaped" bit and shows up the observing strategy of Sloan which imaged the sky in big stripes continuously taking data and reading out the cameras. It was a very clever and fast way to image large areas of the sky. Lucky for us thought the images are all consistent, so we can use these different patches on the sky as one data set to study galaxies with Galaxy Zoo classifications (no need to worry about different classes in this case, although that's a good scientific way to think about data). I have asked Aardvark to learn about RA and Dec and describe this plot as part of his report. I'm excited to see how he gets on looking at the other columns in the table I sent him in the next few days. :)