Galaxy Zoo Talk

Swan Formation

  • wwg1775 by wwg1775

    This one appears quite unusual. What seems to be going out there?


  • zookeeper by zookeeper admin, scientist

    It's a tricky one - the spectrum shows a QSO in the central object but it's not clear why that isn't directly associated with the other two systems. It must be an interaction, but it's not clear to me whether it's two or three things colliding. Triple #mergers are rare but possible, but my gut instinct is that it must be a double merger which has directly disturbed the top galaxy and this will all settle down into an elliptical. The problem is we don't have velocities for these systems so it's hard to disentangle.

    Fascinating though.


  • ttfnrob by ttfnrob scientist

    Could it be a merger with a foreground object (the white thing) that is not associated? Just that the colours seem quite different.


  • mlpeck by mlpeck

    The blue object was targeted as a #QSO but the spectrum looks decidedly post-starburstish. The MPA pipeline line index measurements have Lick HδA = 5.08 ± 0.39 Å and D4000n= 1.045 ± 0.007(*), which is well into the fading starburst region of the HδA-D4000n plane.

    Also there are two spectra of the long thin galaxy to the north (below the blue clump in this picture) and the redshifts are the same - the thin galaxy has z = 0.0849167 while the blue clump's is z = 0.0851474. For some reason the spectra of the neighbor to the blue clump don't show up in Navigate but the plate, MJD, fiberid combinations are (972, 52428, 199) and (972, 52435, 195).

    (*) stuff I learned to look at while participating in the apparently defunct Quench project.


  • Budgieye by Budgieye moderator

    also imaged as


  • Benescu by Benescu

    What if there are 2 mergers but the blue light comes from the "contact" point of the galaxies?