Entropy Production During Star Formation: An Analytic Thermodynamic Framework from the Main Sequence to Compact Remnants

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper is focused on a closed-form method for the estimation of the entropy production which occurs at star formation. The method is, in brief, as follows. The authors take a molecular cloud  and assume that it collapses into a star.  To estimate the entropy at the initial state of the system they apply a standard textbook formula. Then the authors suggest that entropy is carried away from the system mostly by radiation. The final state of the system is composed of the star plus the radiation. To assess the entropy carried away by the radiation they use the gravitational binding enrgy of the star and the effective temperature of the radiation. The method is applied to two groups of objects: main sequence stars, and evolved and compact objects. 

The paper is definitely interesting, the method is original and has the potential to be expanded to other cases. I recommend it for publishing after MINOR revision concerning mostly the substantiation of the method. I would like the authors to answer the following questions. 

1) What fraction of the initial cloud ends up in the star? Justify your answer.

2) How are molecular clouds with such radii and masses classified? The answer to this question is potentially relevant to the previous one.

3) The authors assume the following estimate of the entropy of the radiation ΔS_rad=ΔE_pot/T_eff. The first law of thermodynamics, however, has one more term, the change in the internal energy of the gas. On what basis has it been neglected? Is it assumed that the temperature of the radiation remains constant during the process of star formation? Quantitative justification is due here.

 

Author Response

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Reviewer 2 Report

Comments and Suggestions for Authors

Report attached as a PDF file.

Comments for author File: Comments.pdf

Author Response

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