12:00–1:00 pm ERC 501
Host: Jeff McMahon
Dan Fabrycky "It's 2023. Where's my Jet-pack and Exomoon?"
There are 5,300 known extrasolar planets. NASA's ongoing transiting mission (TESS) has provided 4000 fresh exoplanet candidates. The solar system is awash with natural satellites (moons), yet no fully vetted moons of exoplanets (aka exomoons) have been discovered. The conventional wisdom is that transiting planets are the most sensitive way to find them. Transit discovery is highly biased to short orbital periods, so tides might destroy those systems. We detail calculations (with UChicago undergrad Andrew Kisare) showing that gaseous planets might retain their rocky exomoons in a quite observable configuration, despite being rather close in to their stars. This work is theoretical encouragement for a renewed exomoon search among the TESS exoplanet candidates, in the wake of Kepler photometry turning up two marginal exomoon candidates. This work does not address the lack of jet-packs.
Elena Pinetti "Putting all the X in one basket: X-ray constraints on sub-GeV dark matter"
Putting all the X in one basket: X-ray constraints on sub-GeV dark matter We looked at light dark matter particles, with a mass between 1 MeV and a few GeV. These particles can annihilate or decay into electron-positron pairs which can upscatter the low-energy fields in our Galaxy and produce X-ray emission. By using the X-ray data from Xmm-Newton, Integral, Suzaku and NuStar, we derive strong constraints on MeV dark matter. In the decay scenario, our bounds are the strongest to date, essentially in the entire mass range of interest, and improving up to 3 orders of magnitude upon existing limits. In the annihilation case, our constraints are the strongest available for dark matter masses above 180 MeV.
