Galaxy Zoo Talk

New images from DECaLS (Data Release 2) now in Galaxy Zoo!

  • KWillett by KWillett scientist, admin, translator

    Hi everyone,

    I'm really pleased to announce that a new set of unclassified images has just been put into the Galaxy Zoo interface. These are images from Data Release 2 (DR2) of the DECaLS survey, which many of you helped classify over the last several months. After finishing all of the 30,000 images from Data Release 1, we're excited to have gotten another year's worth of data off the telescope covering tens of thousands of new galaxies taken with the CTIO telescope in Chile. These images all have improved resolution and deeper sensitivity than the Sloan images, so we hope that you'll be able to continue identifying fainter features like mergers and tidal debris.

    The analysis on the first set of DECaLS images is now underway in conjunction with our colleagues in the DECaLS survey, but I hope lots of you will be excited to classify and discuss these image for the very first time. Please post here if you have any questions; the GZ team and our excellent moderators will help however we can.

    Posted

  • KWillett by KWillett scientist, admin, translator

    FYI: we've noted that the Examine page is having difficulty displaying the images and metadata. We'll try to get that fixed ASAP.

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    It seems DECaLS DR2 classifications also don't add up with the classification count under profile.

    I was wondering if the analysis / research only focusses on the combined classification data or also on individual objects, such as posted in the 'further research' thread.

    Thanks

    Posted

  • ElisabethB by ElisabethB moderator

    The classification count should only take into account the images you have classified. It has nothing to do with how much you post on Talk.

    If it doesn't add up, that is probably a bug. I'll flag it !

    Thanks for notifying it ! 😄

    Posted

  • Capella05 by Capella05 moderator

    Yay - new images!

    😃 😄 😃

    Posted

  • bluemagi by bluemagi

    Examine page still won't come up. Thanks BM

    Posted

  • KWillett by KWillett scientist, admin, translator

    Yes - I'm really sorry about that. We're trying to get that addressed as soon as we can!

    Posted

  • EyeOnSkies by EyeOnSkies

    WE LOVE IT!

    Posted

  • KWillett by KWillett scientist, admin, translator

    Examine pages should be up now for all images. Please let us know if you find anything that still doesn't work. Sorry for the initial inconvenience - hopefully this will let everyone explore and learn about the galaxies you're helping to classify!

    The DECaLS sky browser (linked from the Examine page) has also been updated, and you can look between lots of different layers, including DR1 and DR2 comparisons.

    Posted

  • ElisabethB by ElisabethB moderator

    Yessss ! 😄 Great news ! Tx.

    Posted

  • Budgieye by Budgieye moderator

    DECaLS has a forum, not much on it yet. https://groups.google.com/forum/#!forum/decam-legacy-survey

    Posted

  • fred_neill by fred_neill

    Is "Galaxy Zoo Examine" actually in the right place? - I query because a number of the recent images to classify seem not to include any obvious bars, spirals, etc., - that is until AFTER you have classified them and can then look into "Galaxy Zoo examine" where Skyviewer ((magnified) or 'residuals' often seems to show them - you can then only 'return to classify' (or close)

    Posted

  • Budgieye by Budgieye moderator

    Once you have classified a galaxy, you can't return to it. The next galaxy will be waiting for you in classify.

    About more detail, maybe the classification images are slightly compressed for transmission? (I am guessing)

    Maybe someone else can explain about residuals.

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    As far as i have read, Residuals is nothing more than the stuff that is left after the Model is substracted from the actual Image.

    And while classifying, it is also possible to 'invert' the image, which usually helps to see these structures better, if it's not '#wrong_size' 😃

    Posted

  • fred_neill by fred_neill

    Cheers & many thanks both for that.

    Certainly I have classified several images recently and really seen very little obvious other than them probably being discs. However, then when you open via 'comments' and look at 'Skyviewer' or 'residuals,' bars and/or spirals appear to be there. I almost always 'invert' anyway plus do use '# wrong-size' (though less often tending to use Skyviewer) - yes, these can both sometimes help - however, if you could access Skyviewer, etc,. actually when you classify would that not increase the % of "correct" classifications?

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  • CeciliaB by CeciliaB

    After having classified an object, you can find out more about it through 'Galaxy Zoo Examine' and add this information afterwards in 'Talk' by this procedure:

    Click on PROFILE in the Classifying page where you will see your object again. Click on the image and choose the link 'Discuss this object' to the right, which will send you to 'Talk' with an image of your object and a space for comments.

    Posted

  • Budgieye by Budgieye moderator

    Peeking at the collected data and other people's answer might give a more "correct" answer, but two things wrong. All our classifications are done "cold" ie, no access to any information, just your brain. So all results can be compared because they are collected the same way. The other objection is that you are less likely to find something "new" because you are not trusting what you see.

    There is no wrong answer. If 50% say "smooth", and 50% say "features or disk" , the diversity of classification is information too ie. it doesn't fit easily into a single category.

    If you look at enough galaxies, you start to understand what you are seeing without access to data, but still classification must be done cold ie. no guessing that it is a spiral if you can't see the arms.

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  • CeciliaB by CeciliaB

    I realize of course that all classifications should be done "cold".

    I just meant that there could be interesting things to discuss after you learnt more about an object 😃

    Posted

  • Budgieye by Budgieye moderator

    Sorry CeciliaB, you are of course correct. I think I was answering a question that has been deleted. I should remember to click respond when I answer a question.

    Posted

  • fred_neill by fred_neill

    OK - I'll wave a white flag and carry on here, with the Penguins & in New York!

    Posted

  • ryancaffrey by ryancaffrey

    Hey Fellow Astronomers me and my fellow earthlings are doing a project how do we find the g and r values for the galaxies we classified

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