Eventually, NASA will go forward with one (or neither) of these missions. However it ends up, being part of an AXIS working group and collaborating with folks from all over the world has been a really cool experience 💫

AXIS is competing with another proposed probe called PRIMA, a far-infrared observatory. They also have a science book out: arxiv.org/abs/2310.20572

When tMSPs do not host an accretion disk, they are indistinguishable from other "spider" millisecond pulsar binaries. I contributed to another science case in this AXIS white paper that is all about how the proposed probe could enhance our understanding of those systems too.

We simulated the light curve that AXIS would detect for a moding tMSP at the flux level of 4FGL J0639.1-8009, a candidate tMSP that I published in my first PhD paper. This source was observed by XMM-Newton and was too faint to bin finely enough to see these modes. AXIS would totally detect moding!

Some candidate tMSPs in the Galactic field that we already know about are too faint for current X-ray facilities to detect really short timescale variability. Unfortunately, this signature is the "smoking gun" of tMSPs: switches between a high and low X-ray mode that occur within seconds.

Someone made this list of the reps that are publicly on the fence. Call these ones, even if they are not in your district!