Lecture Questions - Day 3 (2022)

Questions for the Day 3 Lectures can be posted here.

Such a great talk on parameter estimation! Is it possible to produce corner plots from a multitude of GW events – i,e, correlations between parameters from many BBH mergers?

Hi @AnnaChrys_ip2i, you can find online all the posterior samples for all the published events so, since you have the ‘raw’ files, you need just to play a bit with them and you can make all the corner plots you want.

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Great talks, thank you ! A question here from the Lyon’s hub on the Q-Transform: what is the recipee to determine the Q-range to be used in the Q-transform function ?

Hi @Patrice, I replied to a similar question here. In addition to that, I would say the order of magnitude of the optimal Q is similar to the number of cycles of the signal you recover.

Thank you @Agata for the link. Question from the students here is related to the tutorial 1.3, where a range [80,110] is used. It was not completely clear yesterday when we did the tutorial how this range was determined: why [80,110] and not [70,120] ? and how the final result is affected by this choice.

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Hi! Thanks! Yes, it indeed is possible. Some examples are here:

https://bilby-gwtc1.github.io/

Specifically, you can go to summarypages of each event > Result Pages > bilby > corner, and click on “all”.

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I had a doubt regarding the certification procedure. Is the certification based on our performance in data challenges? Or do we just get a certificate once we complete the course and submit all the answers? Since the evaluation of the answers to data challenges will happen after the week-long target.

As far as I have understood, the best choice of the q-range is the one that makes the plot looks better (i.e. the signal more visible), I don’t think that there is a perfect value to be chosen a priori, caveat the consideration about the order of magnitude I was mentioning. In other words, I try different intervals and I chose the one that looks better.

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Hi @Saksham, the correctness of the answers to the challenge does not affect the certificate, it is based only on the fact that you have done all the foreseen activities so it doesn’t matter if you replied correctly to the questions.

@aditya A belated “super thanks!” for the link and your instructions! It is phenomenal to have a platform with the posterior samples for GWTC-1 at our fingertips.