Did someone say arc?

• by Budgieye moderator

  nice shape! , though arc doesn't seem to be centered on nucleus

  http://talk.galaxyzoo.org/#/subjects/AGZ000app8

  http://www.galaxyzoo.org.s3.amazonaws.com/subjects/decals/standard/J103439.14%2B033534.2_standard.jpeg

  http://imagine.legacysurvey.org/?ra=158.66307943141203&dec=3.59284552937426&zoom=14&layer=decals-dr1j

  

  http://skyservice.pha.jhu.edu/DR9/ImgCutout/getjpeg.aspx?ra=158.66308952&dec=3.59284661&scale=0.09903175&width=512&height=512&opt=&query=

  http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?ra=158.66307943141203&dec=3.59284552937426ra=158.66308952&dec=3.59284661&scale=0.09903175&width=512&height=512&opt=&query=)

  

  http://skyserver.sdss.org/dr9/en/get/specById.asp?id=649710806413371392

  Is that an extra peak at 7304 ? and 6821

  http://dr9.sdss3.org/spectrumDetail?plateid=577&mjd=52367&fiber=242

  Posted September 26, 2015 7:29 AM

• by ElisabethB moderator

  Not sure if it is a real arc, looks like an artefact to me.

  Here's another example of squiggly red lines : http://talk.galaxyzoo.org/?_ga=1.164672892.259766795.1441311472#/subjects/AGZ000aqrh

  Posted September 26, 2015 7:57 AM

• by drphilmarshall scientist

  Suppose it's a lensed arc:

  The wavelengths of the two lines don't seem to match up to the usual emission line suspects - but I guess the one at 7304 is suspect for being in amongst the sky lines, so if we ignore that one, we're left with a single emission line at 6821. That could be H-alpha at z=0.03 or lyman alpha at z=4.6, so a nice red galaxy... Itd be interesting to know the angular sepration of the red squiggle from the center of the elliptical.

  I'm not sure the spectroscopic fibre would have caught this red squiggle - the galaxy looks like a big nearby elliptical galaxy, so the spectrum may only be of the central region. If its a lensed arc then I guess the spectrum could contain a central counter-image, if the lensing geometry made sense.

  Now suppose it's an artifact:

  Have you seen other things like this that are not tangentially aligned around massive-looking galaxies?

  Posted September 27, 2015 12:52 AM

• by zutopian in response to drphilmarshall's comment.

  Have you seen other things like this that are not tangentially aligned around massive-looking galaxies?

  On below DECaLS images there are similar red things, but they aren't curved.:
  http://talk.galaxyzoo.org/#/subjects/AGZ000b97y
  http://talk.galaxyzoo.org/#/subjects/AGZ000alvo

  On below DECaLS image there is another red arc, but this one doesn't surround a galaxy.:
  http://talk.galaxyzoo.org/#/subjects/AGZ000avfz

  Posted September 27, 2015 9:20 AM

• by zutopian

  Here is another red linear object (DECaLS)!
  http://talk.galaxyzoo.org/#/subjects/AGZ000awfa

  Posted September 28, 2015 6:22 AM

• by williamaskew

  When I first came across this it was suspect but since then I have come across several more but straighter . ARCIFACT

  Posted September 28, 2015 6:40 PM

• by vrooje admin, scientist

  ARCIFACT

  😄 😉 😄

  Posted September 28, 2015 7:33 PM

• by Budgieye moderator

  Ho, ho, very punny! 😃

  Posted September 28, 2015 7:39 PM

• by Capella05 moderator

  😃

  Posted September 28, 2015 8:07 PM

• by Capella05 moderator

  I have created a hash tag collection here for all these weird red artifacts from DECaLS: CGZL00006l

  Just tag an image with #decals_red_artifact and it will get automatically added into the collection.

  Posted September 30, 2015 4:24 PM