Re: Nova Aigle
Posted: Thu Nov 05, 2015 8:53 pm
Hello Benji,
I would disagree with you. In the spectrum you object the average signal is positive even below 5000 A. What you see are peaks below zero caused by noise, which occur when S/N is around or below 1. In that case your reasoning about inequalities ( S+N > 0) are not valid. It would be a mistake to subtract less sky just to get the the noise peaks above zero. The S/N is just not good enough to measure the continuum, which is understandable with the brightness of the Nova and the position of the Nova in the sky. I fully agree with Huberts explanation. I cannot see anything wrong with his treatment.
Regards, Martin
I would disagree with you. In the spectrum you object the average signal is positive even below 5000 A. What you see are peaks below zero caused by noise, which occur when S/N is around or below 1. In that case your reasoning about inequalities ( S+N > 0) are not valid. It would be a mistake to subtract less sky just to get the the noise peaks above zero. The S/N is just not good enough to measure the continuum, which is understandable with the brightness of the Nova and the position of the Nova in the sky. I fully agree with Huberts explanation. I cannot see anything wrong with his treatment.
Regards, Martin