Apr 19
Merger hunting the easy way
I posted a request yesterday afternoon for help in sorting out a set of possible mergers; as the developers are busy with Zoo 2, I just posted a set of lists. Clunky, and annoying, but I’d hoped people would still be able to help out. By the end of last night, forum member Waveney had built us a proper interface. You’ll find the address at the end of the instructions below.
1. Read Daniel’s guide to what makes a Galaxy Zoo merger, available as a pdf file.
2. Go to Waveney’s site and register (make up any name and password you want).
3. Classify away.
4. Sit back and relax.
The site is not operationnal (at least with my firefox). When clicking on register, it offers a merger to sort (always the same, I’ve tried a few times) and does not consider any answers… Still some work to do…
It works for me in firefox. What version are you using?
Currently 13 people have successfully used it. I use Firefox and others (but not IE). Florian - I can’t see an obvious user name entry for you what did you use - I may be able to see what is happening.
none, when I click on “register” it sends me directly to galaxy n°587724199885406295.
It is v2.0.0.14 (maybe because it is the french version?)
I have tightened up the checking when starting, so that you can’t click register without a username or password. I think this is what has gone wrong.
That’s cool, I just had the same thing - I clicked “register” first. Make up your username and password first, then click “register”, then you’re fine.
Waveney, this is brilliant, a new Galaxy Analysis site! Thank you so much for making it. By the way, how are you doing the image feed - is it random, like Galaxy Zoo?
I am using the list of Objects provided by Chris yesterday. Each user will start at a random image number and then work through the 15500 images in sequence. It keeps a record of the last one it sent you.
Waveney are we overloading your server? It’s all gone very slow my end.
Once again the GZ community shows it’s worth! Big ups & many props to Waveney!
p.s. I’m sometimes getting the same image repeated immediately - not a problem I hope…
Thanks for the tutorial PDF. And thanks again to Waveney for the great site - it should solve my little headache.
Is there any record of the references of the galaxies we worked with day by day ?
I like the “Zoom In” and ‘Zoom Out” buttons a lot, Waveney.
Nice touch.
Any chance we can see our “Merger” count stats ?
Regards, diaswa
Tarquin - Sometimes the same merger has several different Object Ids (eg one for each galaxy) these are often similar numbers and hence will appear together in the way I organise the data.
Lehensuge - I am not sure I understand what you want. Yes there is a list of galaxies you have said Merger/Not a Merger to. Its not currently in a convenient form to display. Please explain what you want (best in the forum)
This is great! I’m happy to be classifying again. Sorry for all the mistakes…
OK, so I read the tutorial and registered on Waveney’s site and started chugging through, but I’m not at all comfortable.
Considering, for example, 587724233710305473 which I would be strongly inclined to reject as a projection overlap rather than a merger - my instinct says that two galaxies really intermingling that much would show much more distortion (they’re pretty fluid - right?). Yet in Daniel’s tutorial fig 5 (2) and (5) and fig 6 (11) look awfully like it, and Daniel says “Yes!” and Daniel’s the astronomer.
I analysed http://cas.sdss.org/astro/en/tools/explore/obj.asp?id=587724233710305473
in the same manner for most of the mergers?
ie. zoom in or out / invert the image- decide.
No distortion, no stars interfering so it’s projection(line of sight)ie. NOT Merger.
Occasionally, one queries is it an early merger?
In this case, for your example Brian I noted it’s z distance, did an NED search to find z data for both ellipticals, namely 0.142 and 0.135 and noting errors. They are quite well separated ca. 80 light years if you use Ned Wright’s calculator.
http://www.astro.ucla.edu/~wright/CosmoCalc.html
cf. the Milky Way and Andromeda ca. 2 light years.
Actually when the 80 ly popped up I thought that looks too distant!
Finally, Daniel’s Fig5 (2) does look more projection than merger from the pdf file. He could be wrong and so could I lol.
I spend about 10-15 times longer looking at each merger? than for the GZI images, but considerably more doing NED searches etc for those ” grey mergers”.
Finally it’s definately projection ie. Not a Merger
Glad to be of assistance - the zoom button really helps to see if there is/might be intermingling
Witam wszystkich!
Na rozgrzewke to moje laczace sie galaktyki?
http://cas.sdss.org/astro/en/tools/explore/obj.asp?id=588017705088057501
Czy na tej stronie nie ma polskich liter?
Mergers are fun and the web interface works well. However, I keep running across nice mergers with probable foreground stars in or very near the merger.
From the tutorial, it seems these should be classified as “not a merger” or “don’t know”, since you don’t want stars to contaminate the sample. Doing so feels wrong, however, when there is obviously a merger going on behind the foreground star or stars.
Have I misunderstood the tutorial? If not, it would be nice to have a “merger with foreground stars” button as a classification option.