Blogs

How Many Gravitational Waves have we seen?

Last week I got an email from a colleague, asking a question which, on the face of it, should have been easy to answer.

How many gravitational waves have we detected?

However, the fact that they needed to ask helps to reveal that there is not, in fact, a straightforward answer.

This is hopefully a complete, and fairly concise, set of potential answers to the question, along with caveats as appropriate.

Going Beyond GWTC-3

+++ It started as a nice, simple, short project to test some code I was working on. Things… got out of hand. Today I’ve submitted a paper describing a project I’ve been working on for around 18 months, which was not initially planned as a paper.

The story of this paper

In summer 2023 I was working on asimov which is software designed to help coordinate the analyses of on of the major “catalogues” of gravitational waves which the LIGO, Virgo, and KAGRA (LVK) collaborations put together for each of their observing runs. We used this software for our O3 runs, and producing the GWTC-2{cite}Abbott_2021, 2.1{% cite catalog-gwtc-2d1 %}, and 3{% cite catalog-gwtc-3 %} catalogues, but I was very aware that in order to cope with the large number of events we were expecting in the fourth observing run that I’d need to rewrite parts of it, and then thoroughly test it.

What's a good marathon time?

I seem to be incapable of just doing something without wondering about the statistics behind it these days.

Back in May I ran my first marathon (and I reckon I finished in a decent time, 3h24m. I was aiming for under 3h45m). Much as [when I ran the Glasgow half last year]({% post_url 2023-10-06-whats-a-good-time %}) I found myself wondering how it really compares.

As ever, getting access to the data is a process akin to tooth pulling, but you can get the resulting csv file from this gist.