Interesting red arcs - any ideas?

https://www.legacysurvey.org//viewer/?ra=343.3608&dec=1.0954&layer=hsc-dr2&zoom=16

This has an AGN

If you mean the very thin red track that looks like it’s aligned with the spiral arm at 6 o’clock from the galaxy center, I think that may be a cosmic ray. Zooming in a bit,

There also seems to be a red tint to the southern side of the galaxy core – I don’t know what that is!

Yes, I see the track, but there is also a red tinge to the lower part of the core. It’s also in DR9.