Stellar magnitude distribution


I chose 200 random fields using opsim–minion_1016 (fieldRA, fieldDec and expMJD) and I plugged that into catsim to obtain a stellar catalog by querying starObj from the allstarforceseek table. I obtain a peak around magnitude 20 and it’s pretty surprising. Why is this peak appearing? Any hints?magnitude_stars.pdf (13.7 KB)

When I require a 5sigma detection limit on r band >=24.5 the distribution changes slightlymagnitude_stars_new.pdf (13.7 KB)

When you say you chose 200 random fields, are you just using the pointings from opsim - or also the limiting magnitude information?

I select pointings from opsim that have a 5sigma detection limit higher that 24.5. I say random because I select them randomly from the table without following any ordering scheme. When I use catsim I am not introducing any limiting magnitude information, I only use ra, dec and expMJD from opsim to query stars in the starsallforceseek table. According to Scott Daniel it can be related to some issues at the time of introducing extinction in the MLT dwarfs.