Change in brightness
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What could cause the abrupt change in brightness on the right side of this galaxy. Found another one today :
https://www.galaxyzoo.org/#/examine/AGZ000cuxk
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by ElisabethB moderator
I'm not sure what you mean with 'an abrupt change in brightness.
Both these galaxies are disturbed spiral galaxies, so they wouldn't look symetrical.
Hope this helps and happy hunting ! 😄
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Thanks. In the first image (AGZ000czfs), as we move right from the nucleus,, the brightness changes at point. It is visible like a vertical line. The brightness of the galaxy beyond that point is much lower. The right-most spiral arm starts below the nucleus and is quite bright near the nucleus but dimmer later,
The straight line appearance is what drew my attention to this. I thought that it looked unnatural and wondered what could cause this abrupt change. Either there are fewer stars or dimmer stars in these less bright parts of the galaxy.
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by Budgieye moderator
Anything that is is a sharp line is an artifact. After a while you don't see them anymore.
Galaxies are fuzzy.
These images have been taken apart and put back together to a surprising extent.. The bright parts have been masked. Possible cosmic hits have been lasooed, cut out, and an average background put in. Images are sewn together and the adjoining areas sometimes don't match. Lines of ccds have variable performance on different days.
http://cas.sdss.org/DR3/en/proj/advanced/processing/
You might want to look up the original images, and see if the dark area is on them. It will probably mean learning to use FITS files.
7.7 data analysis and FITS images https://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000wrb?page=7
https://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000wrb?page=8
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I have not used FITS files so far. Will take a look at the links you mentioned.
Thanks
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Another one. The left half is not as bright as the rest of the galaxy.
https://talk.galaxyzoo.org/#/subjects/AGZ000d1fs
DECaLS DR3
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