Author Topic: A few newbie questions.  (Read 1932 times)

Danisimo

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A few newbie questions.
« on: July 07, 2012, 04:51:52 pm »
Hello.
I'm new to the galaxy zoo and it all really interesting but I'm having trouble classifying some galaxies and I'd really like to give as accurate results as possible so I'l ask some questions here to prevent mistakes.
First. What exactly are artifacts? I don't fully understand the term.

Second. What is the difference between irregular and disturbed galaxies? I can't seem to figure that out.

Third. Some galaxies just seem to be really close to each other and some are mergers. I have a perfect example for this. http://www.galaxyzoo.org/examine/AHZ2001out Is this a merger?

Fourth. While reading the tutorial i saw some examples of galaxies with a pretty obvious bulge being classified as smooth and i was wondering how exactly do you classify those? Should i mark them as smooth and mark the shape or should i click on "features or disk"?

Fifth. Galaxies that have a bright center bulge and a perfectly round disk. Are they classified as smooth or with features/disk? When i click the second option it only asks me if it's a ring or spiral so I'm not entirely sure about that too. Example. http://www.galaxyzoo.org/examine/AHZ2001sru It has a noticeable bulge and a disk but there i can't seem to find the right classification for it.

Sixth. Lens or arc. I've looked at the tutorial but i still can't understand what exactly I'm looking for. Pictures that are classified as Lens or arc in the tutorial section just seem like pictures with multiple galaxies to me. http://www.galaxyzoo.org/examine/AHZ6000d21 Would this be it?

I apologize for the rather long post. Any and all help will be appreciated.

EDIT: I just got this and i have no idea what I'm looking at.  There's a very bright light. It might be a star.
« Last Edit: July 07, 2012, 05:06:52 pm by Danisimo »

elizabeth

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Re: A few newbie questions.
« Reply #1 on: July 07, 2012, 07:43:37 pm »
Hello.
I'm new to the galaxy zoo and it all really interesting but I'm having trouble classifying some galaxies and I'd really like to give as accurate results as possible so I'l ask some questions here to prevent mistakes.
First. What exactly are artifacts? I don't fully understand the term.

Second. What is the difference between irregular and disturbed galaxies? I can't seem to figure that out.

Third. Some galaxies just seem to be really close to each other and some are mergers. I have a perfect example for this. http://www.galaxyzoo.org/examine/AHZ2001out Is this a merger?

Fourth. While reading the tutorial i saw some examples of galaxies with a pretty obvious bulge being classified as smooth and i was wondering how exactly do you classify those? Should i mark them as smooth and mark the shape or should i click on "features or disk"?

Fifth. Galaxies that have a bright center bulge and a perfectly round disk. Are they classified as smooth or with features/disk? When i click the second option it only asks me if it's a ring or spiral so I'm not entirely sure about that too. Example. http://www.galaxyzoo.org/examine/AHZ2001sru It has a noticeable bulge and a disk but there i can't seem to find the right classification for it.

Sixth. Lens or arc. I've looked at the tutorial but i still can't understand what exactly I'm looking for. Pictures that are classified as Lens or arc in the tutorial section just seem like pictures with multiple galaxies to me. http://www.galaxyzoo.org/examine/AHZ6000d21 Would this be it?

I apologize for the rather long post. Any and all help will be appreciated.

EDIT: I just got this and i have no idea what I'm looking at.  There's a very bright light. It might be a star.

:D :D Welcome to the zoo.  Here is a good place to start link#3 might be a overlaplink

Alice

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Re: A few newbie questions.
« Reply #2 on: July 18, 2012, 12:33:14 pm »
Welcome to the zoo Danisimo!

I agree with Liz on the good place to start :)

1) An artifact is something the camera has done, usually a flare - something very bright that messes up the image (often with spectacularly beautiful results).

2) An irregular galaxy is a galaxy without any sort of structure, like spiral or elliptical. They often look like blue clouds. A disturbed galaxy is a galaxy which is interacting with another, or clearly has done in the past, so it's pulled out of shape.

3) I'd classify that as an overlap. (But even if you put merger, it's OK. It can be checked.) If galaxies are merging, they'll be pulled out of shape, for example long arms or loops or just silly shapes.

4) I'm often confused about that too :D I think it's easy to confuse "bulge" with "core". This, for example, is a core not a bulge:

and that is a smooth galaxy. A bulge is this, what you see in the edge-on galaxy, an actual shape:


5) I'd call that a spiral. I can see spiral arms, even though they're embedded within the disk.

6) A lens or arc is a curved, often discoloured (blue or grey) "ring" shape, or piece of ring, around the galaxy, this for example.

Hope all this helps! Don't worry too much about getting it "right". The most important thing is that this is not a test, with the answer in the back of the textbook. We are not aiming for single "answers", but for varieties of everything people see. If different people say different things about galaxies, it is a good thing - it means the galaxy has lots of features to study.