Ring without references
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I found this ring buried in the Ultravista images (IR) and was wondering what it is. It is not in any (useful) reference in SIMBAD or VizieR. The ring seems to be bigger in Ultravista Y and J band, a bit bigger in H band (deformed) andbrightest in Ks band.
Planetary nebula / supernova remnant?
149.40737 +01.68740
Color image and single band images from Ultravista, same size and center.
Posted
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by
Budgieye
moderator
I would ask someone in the Milky Way Project.
https://www.zooniverse.org/projects/povich/milky-way-project/talk
and include the link to Ultravista
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by
Ghost_Sheep_SWR
in response to Budgieye's comment.
Yes I thought about doing that first, but figured they're more about bubbles (young stars) than possible supernova remnants.
But will do, thanks!
EDIT: https://www.zooniverse.org/projects/povich/milky-way-project/talk/508/506368
Posted
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at the Milky Project moderator @Melina_T already responded:
A distant Planetary Nebula or Supernova Remnant would be closer to the
galactic plane. So I would say it is not a PN or SNR. A proto-PN or
disk should be visible in 24 um, but the spitzer images do not show a
source.
Green circle is the position you mentioned @Ghost_Sheep_SWR and 5''
diameter. My guess is that it is a galaxy
But I just found out something that is weirder still; it is visible in Ultravista H + K Band images, but not CFHT H + K band images which AFAIK is the same filter / wavelength:
CFHT K band
CFHT H Band
It is however visible in Subaru bands B V g r i z
Images from the Panchromatic Swarp Imager
http://cutout.icrar.org/tmp/15143084438614/index_temp.phpPosted
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As was proposed by moderator @Melina_t it may be an unknown light echo, so I will try to retrieve all the observation dates from the different surveys in order to make a reconstruction in time.
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Does anyone how to retrieve the Subaru images for exactly 149.40737 +01.68740 / 09:57:37.78 +01:41:14.8 like the GAMA Panchromatic Image Swarper is showing?
It seems I can get a lot of images that are very close to those coordinates but not cover the possible event in Aladin Desktop and the SMOKA Subaru archive. No idea were GAMA is pulling them from.
EDIT: managed to get the images and dates, definitely something visible there
Posted
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MWP Moderator Melina_T pointed me at a somewhat similar feature closer to the very bright star to 6 o'clock at 149.40758 +01.66346, so it does seem it's going to be an artifact after all.
Some more CFHT images to check, but nothing to be seen anywhere in time or different filters. Which is also a bad sign.
BUT, still there is the source in the Subaru images, also artifact at the exact same location??
Aslo still to check: Ultravista (EDIT VIRCAM) images, about a hundred.
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I might have found some more fainter ring-like structures in the Ultravista field, and the FITS files are just waaaaay too big for me to download, might take me days at best. Also the Ultravista FITS headers aren't useful at all because they descibe an observation start date and end date from 2009 to 2014, so says nothing about the actual observations dates.
So I'm calling it a day and say Artifact. It isn't visible in about 10 surveys (optical + IR) spanning a period between 2000 - 2017 except in two.
That leaves me with the unexplained clear source in the Subaru images, which might also be an artifact at the exact same location?? Here are the filters and observation dates and two images to illustrate, more visible in the link below:
- Filter W-S-G+ 02-14-2005
- Filter W-S-I+ 02-20-2004
- Filter W-J-V 02-19-2004
- Filter W-S-Z+ 01-18-2000
- Filter W-S-R+ 01-19-2004
- Filter W-J-B 01-20-2004
So these don't overlap with the Ultravista images from 2009-2014.
More images from the GAMA Panchromatic Swarp Imager
If anyone else has some insight to add would love to hear it, for now I'm at loss what else it could be in both Ultravista and Subaru images.
Posted
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by
NGC3314
scientist
If you can get the entire original FITS frame for the IR data - some IR detectors are notorious for having crosstalk between signals carrying out data in multiple quadrants, so a bright star will leave a ghost image at the three points symmetric in x,y, and both. (I have never ever been burned by this. Honest).
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I'm sure you haven't.
For the Ultravista field at least I've learned from the VIRCAM FITS files that the complete field is observed in smaller consecutive areas (from top to bottom, then move to the right and up again) so that can quite well explain the latent / ghost artifact ring.
For Subaru I might re-download the entire FITS files again just to check for more ghosts. I've deleted all but some Subaru cutout files, these things are HUGE. Makes you think about data from future telescopes....
Thank you for the feedback.
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