Update expected BNS detection rate following O4a
There's been lots of discussion about updating anticipated BNS detection rates in O4b/O5, following the non-detection of confident events in O4a (see email thread initiated by Om and discussed on Jan 25, 2024 R&P call). I'm starting this issue to hopefully act as a central place to continue discussion!
Following the R&P call, remaining questions are the following (copied over from Maya's email on Jan 25):
- do we want to use information from public alerts in O4a, or base the estimate simply on O1-O3 published events?
- do we want to use (and release) an O4a PSD to calculate VTs?
- do we want to update the O5 numbers as well? (observers will probably ask?)
- do we want to restrict the update to BNS detections? or include NSBH and BBH? (we probably don't want to reveal too much about NSBH events in O4a.)
- other details about the BNS mass distribution to assume, etc., although it won't matter much because the VT ratio is fairly insensitive to this.