Expid=209811, tileid=21337 from 20231214: small vertical features in the r sframesky

[araichoor]

Out of cautious, I ve marked this tile has "unsure".

The sframesky image has those features in r1, which look a bit sharper to me than usual:

The redshifts look fine to me:

[schlafly]

@julienguy , you and I wanted to follow up here. The proposal on the call was to call these good as the small residual feature in the sframes seems very unimportant on this bright tile. But this is a case I haven't seen before where plausibly some of the sky PCA stuff is locking on to something weird on a lot of fibers, which is odd?

[schlafly]

Let's just mark this as bad and try again. @abhi0395 , @akremin , 20231214/209811, tileid 21337. Thanks!

[abhi0395]

@schlafly I have marked this exposure as bad and have re-processed the tile. nightqa and tsnr have been updated. Please close the ticket if everything looks okay to you.

[schlafly]

Fixed, thank you!

[araichoor]

for info, on 20240229, it looks like we had similar features on bright tiles, so I re-open the ticket.
there is no obvious effect on the redshifts, so I ve qa-validated the tiles; but it would be nice to find out the reason :).

this affected almost all the bright tiles after expid=228099:

# EXPID TILEID
228099 21618
228100 21617
228103 23914
228104 22288
228106 22293

the "worst" one being 228100:

[araichoor]

note that a serie of backup tiles from 20240301 (expids 00228218 -- 00228222) also have such features.