Galaxy Zoo Talk

two

  • dderek by dderek

    hi big merger about happen what will would you see if the two centers collided ?

    Posted

  • JeanTate by JeanTate in response to dderek's comment.

    It's far from clear that this is, in fact, a merger (and not a chance projection of two early-type galaxies - ETGs - separated by an Mpc (megaparsec) or more of space. In this regard, Blue_Crew's "notam_word" (which I interpret as 'not a merger') may be highly pertinent.

    Even if these two ETGs are, in fact, close, we know nothing of their relative velocities (and so momenta); it's entirely possible that they'll sail away after their close encounter, and won't come close again for another 100 billion years or so.

    As both seem to be 'dead and red' (or is it 'red and dead'?), there will be effectively zero 'collisions' (dark matter is collisionless, as far as we know, and stars that collide will be numbered in the 'handful'). If - by an extreme case of cosmic coincidence - the two have SMBH (supermassive black holes) in their nuclei, and they're on trajectories such that they'll pass close to each other, they may become a SMBH binary (extremely unlikely, but just suppose), which will, one day, decay into an inspiral (due to loss of orbital energy by gravitational wave radiation), and ... well, that would be exciting to watch! 😄

    But it won't happen before homo sapiens has long since departed, and likely not before Earth is consumed by the Sun going red giant ...

    Posted

  • ElisabethB by ElisabethB moderator

    I would not pay any attention to Blue_Crew's comment. This person was convinced that there was no such thing as a merger., ever.

    Purely by visual inspection, and that is what we do here, it could very well be a merger.

    Posted

  • JeanTate by JeanTate

    Of course. When you can see 'tidal debris', where there are disk galaxies ('spirals') that are highly distorted (and when there's another, similarly distorted, spiral nearby), etc, it's pretty easy to make a 'merger' call.

    For ETGs - 'early-type galaxies', ellipticals and lenticulars (disk galaxies without obvious arms or bars) - it's not so obvious what the visual signs of a merger are. Tidal tails/debris? Certainly good features. Highly asymmetric? Sure. But simple proximity, especially if there's no obvious sign of disruption or distortion, is not enough. And where the two overlap - as here - unless there's something like a backlit dustlane, I myself think caution is called for. Particularly near the center of a rich cluster, where there are lots of ETGs ... for sure many of the overlapping objects are just chance alignments, not mergers (not that these two are in the center of such a cluster ...).

    In this case, the object we were asked to classify is the white blob, not either of the ETGs. Strangely, the photometric pipeline classified this white object as a galaxy ... but the other white objects nearby are all stars. There are no objects with spectra, so we can't use that check. Do you think any zooite would have classified the white object as a merging galaxy? Surely most would say 'star or artifact', wouldn't they?

    enter image description here

    Posted

  • ElisabethB by ElisabethB moderator

    I think at least 80% of the people who got this image would not even consider the white dot and go for the two galaxies (possibly merging). I know I did. Oops ! 😄

    Posted

  • dderek by dderek

    i only asked.

    Posted

  • dderek by dderek

    i have just seen the white blob

    Posted

  • JeanTate by JeanTate in response to dderek's comment.

    Asking is good! 😃

    Posted

  • KWillett by KWillett scientist, admin, translator

    I asked for a recent data dump of the classifications for this object; will let you know 😉

    Posted

  • KWillett by KWillett scientist, admin, translator

    Still waiting on the data. Sorry for the delay!!!

    Posted

  • Blue_Crew by Blue_Crew

    Dr. Willett would you please remind the moderator that personal
    attacks are not tolerated by anyone at the Zoo. Thank you.
    If anyone wishes to inquire about a #word I wrote they can send
    a pm to me and ask about it.
    There is another personal attack at
    http://talk.galaxyzoo.org/#/boards/BGZ0000002/discussions/DGZ00002yk
    . Thanks again for your immediate attention.

    Posted

  • ElisabethB by ElisabethB moderator

    Blue_Crew,

    You have been warned the first time around. Do not start this discussion again.

    Thank you

    Posted

  • KWillett by KWillett scientist, admin, translator in response to ElisabethB's comment.

    Finally got around to reminding myself how the various GZ databases fit together to answer this question (which is moderately complicated, but logical).

    Most people (80%) who classified this identified a smooth galaxy without features, probably the one at the center. However, about two-thirds of classifiers also thought it was "odd", three-quarters of which were for merger.

    I don't know that we can determine from the image alone whether it's a merger or simply a chance-aligned galaxy pair, but the results so far from our classifiers indicate lots of merger votes. The good news is that we have techniques of how to statistically adjust for the likelihood of overlapping pairs (Darg et al. 2010, Casteels et al. 2013) and so the Galaxy Zoo results should be reliable when averaged over the full sample. Thanks for the good discussions, everyone!

    Posted

  • JeanTate by JeanTate in response to KWillett's comment.

    Thanks!

    From that it would seem that no one - or maybe just a tiny handful - of zooite classifiers noticed that the 'object' in the center is not the yellow fuzzy blob but the white star-like thing. Can you check to see if the yellow fuzzy blob is a separate object, in the GZ database (it very obviously is in the SDSS one)? And if so, how has it been classified?

    From a catalog-compiling perspective, this is yet another example of the sorts of blending/shredding confusion that can arise. And of the limitations of having automated routines do classification for us 😉

    Posted

  • Blue_Crew by Blue_Crew

    And if one wishes to leave a hash-word that expresses a classification or description other than those
    officially condoned by the staff what does one write? What are the official replies? Does one need to fear
    reprisals from the moderator for expressing an honest opinion? If the staff is unwilling to afford the classifiers
    alternative replies then what's the point leaving remarks?
    What exactly is the factious crime that one commits in the first place to be blocked and/or chastised by the moderator and staff?

    Posted

  • vrooje by vrooje admin, scientist

    The person who posted above under the username Blue_Crew was previously reported for harassing users with unsolicited private messages and for spamming Talk by creating multiple users to post the same (or very similar) messages. I and others attempted to resolve the issue via public posts and private messaging, and when the individual admitted to the above abusive behaviors and was asked to stop, s/he refused. When it became clear that s/he would not voluntarily cease to harass others, it became necessary to ban the user. This step was not taken lightly and many people were involved in the decision, including moderators and admins.

    That the unsolicited private messages and the messages posted by the same person under multiple user names were related to a scientific hypothesis that is fundamentally in conflict with our understanding of gravity is not relevant. People can hold any opinions they want, but if they try to shout down everyone who disagrees with them, or behave in an abusive manner towards other volunteers, they will be asked to stop. This particular user (or rather the person behind any present or future usernames) is banned from using Talk, but can continue to classify galaxies and is free to use any public data to formulate and test their scientific hypotheses.

    Galaxy Zoo is built on individual, independent classifications, each of which are valuable and valued. We encourage volunteers to explore the data and discuss topics in the community; and, in the spirit of this incredible community, we ask that people approach each science conversation with an open mind regarding what is, and is not, currently known by the scientific community.

    Now back to your regularly scheduled programming... 😉

    Cheers,
    -Brooke

    Posted

  • joi2cjoi by joi2cjoi

    I read the reply to the "report" in the Forum.

    It's very interesting that the exclusion indeed seems to be very one sided.
    Why was Blue_crew not allowed to respond?
    Why did you not answer the last question?
    Was Blue_crew blocked once or twice?

    "resolve the issue via public posts and private messaging,"
    Where is this information?

    http://www.galaxyzooforum.org/index.php?topic=278768.msg611531#msg611531
    this was about fake AGNs and there was a serious outcry. No one was blocked or
    removed from the staff.
    So it's alright to use human psychological guinea pigs as long as they don't know about it.
    How do we know this isn't a fake "report"?

    Let's put the 'citizen' back in citizen science. If you have a problem report it to a mediator.
    If you are still not happy and want to make a formal complaint, please contact the Research
    Ethics Committee at the University of Oxford (ethics@socsci.ox.ac.uk).

    Posted

  • shashi.pushigmail.com by shashi.pushigmail.com

    ethereally beautiful

    Posted

  • joi2cjoi by joi2cjoi

    Unblock Blue_crew.

    Posted

  • joi2cjoi by joi2cjoi

    Unblock Blue_crew or SHOW CAUSE.

    Posted

  • zutopian by zutopian

    Well, I think, that there is actually no right to be a volunteer/Talk user. So I think, that the science team can block users for whatever reason. That's just my humble opinion.

    EDIT: PS: My comment is referring to the discussion on previous page.

    Posted

  • Capella05 by Capella05 moderator in response to zutopian's comment.

    I am new to being a mod on GZ talk, and have no previous knowledge of the issue at hand, But @zutopian I have no idea what you are alluding too?

    edited to add: I am not a science team member.

    Posted

  • zutopian by zutopian

    @Capella05

    I edited my post.

    Posted

  • joi2cjoi by joi2cjoi

    Logon comment: **You have been banned from Talk by a moderator ** posted.
    Who is the "moderator" with authority to do this?
    Why was it done? What is the STATED violation of Talk conduct?
    Where might one find these rules of conduct?

    Where are rules of conduct for the moderator?

    Posted

  • joi2cjoi by joi2cjoi

    UNBLOCK BLUE_CREW PLEASE. YOU HAVE WASTED ENOUGH TIME WITH THIS FARCE.

    Posted