Avoiding Bias in Measurements of Fundamental Constants from High Resolution Quasar Spectra^†

Round 1

Reviewer 1 Report

This paper advocates for the need of careful, unbiased data fitting in works constraining the eventual variation of fundamental constants. It focuses on analyses of high resolution quasar spectra and their use to detect the fine structure constant variation. The authors point out problems of conscious or unintentional bias towards the non-variation of the fundamental constant embedded in the most common practices of data fitting. They underscore the adequate treatment and describe their approach in a good level of details. The scientific contribution by this paper is sound and original. I do recommend the manuscript to be published by the journal. 

Author Response

We are most grateful to Reviewer 1 for the thoughtful comments. We have corrected a few typos that were present in the initial submission and made minor re-arrangements to the text in places. All changes are illustrated in the Latex diff file.

Reviewer 2 Report

The paper is very interesting.  It makes clear the dangers of bias in measurements in physics and especially in astrophysics.  I am not an experimentalist, so I couldn't follow much of their technical analysis.  Assuming another reviewer, who is able to better evaluate the paper from the experimental side, finds the paper equally satisfactory, I recommend it for publication. 

Author Response

We are most grateful to Reviewer 2 for the thoughtful comments. We have corrected a few typos that were present in the initial submission and made minor re-arrangements to the text in places. All changes are illustrated in the Latex diff file.