Observing hot CGM of spiral galaxies from the sky and earth

The hot circumgalactic medium (CGM) is believed to host most of the baryons missing from the stellar disk and ISM and play a key role in galaxy evolution. However, detecting the hot CGM is extremely challenging due to its low surface brightness and the complexity of the X-ray background. By carefully selecting an optimum target, devising an efficient and rigorous method, and performing two independent analyses of our Suzaku and XMM-Newton data, we have detected the integrated emission of the hot CGM of an isolated star-forming spiral galaxy. The temperature of the inner CGM is super-virial, and the surface brightness distribution indicates cavities along the minor axis. It is the first and only L* galaxy (so far) with such intriguing findings. We perform stacking analyses in mm using the thermal Sunyaev-Zeldovich Effect to complement observations of individual galaxies. We cross-correlate the WISE galaxy catalog with the Compton-y map derived from the CMB data of the Atacama Cosmology Telescope to estimate the thermal pressure of the CGM of 0.63 million L* spiral galaxies. The thermal energy of the CGM of these galaxies evolves more strongly with mass than the self-similar relation of purely gravity-driven halos. We also detect a non-monotonic trend of baryon fraction as a function of mass, with a certain mass range being baryon sufficient. Our results provide insights into the impact of galactic feedback on the hot CGM and set a benchmark for designing experiments with next-generation X-ray and mm facilities.