Physics Department Seminar University of Alaska Fairbanks

J O U R N A L    C L U B


Exospheric Neutral Density study at the Earth’s subsolar magnetopause deduced from the XMM-Newton X-ray mission


Jaewoong Jung

Physics Department/Geophysical Institute, UAF



Soft X-rays are emitted when highly charged solar wind particles like O7+ and O8+ exchange electrons with neutral hydrogens. This process is called solar wind charge exchange (SWCX). The Earth’s magnetosheath and cusps are expected to emit strong SWCX emissions due to high abundasces of both solar wind particles and exospheric hydrogen atoms in these regions. The Solar wind – Magnetosphere – Ionosphere Link Explorer (SMILE) mission, selected by ESA and China with launch in 2023, will image the Earth’s dayside system in soft X-rays. To support the SMILE mission, we conduct a statistical study on the near-Earth SWCX signals using the XMM-Newton astrophysics observations. XMM-Newton is the European X-ray telescope launched in 1999 and has been observed cosmic X-ray sources for nearly 18 years. At times, its line-of-sight passes the dayside magnetosheath, and the telescope detects near-Earth SWCX emissions in addition to X-ray light sources like stars and galaxies, diffuse astronomic X-ray backgrounds like interstellar and intergalactic clouds, diffuse heliospheric SWCX signals, and particle backgrounds from the telescope’s own glow. We introduce how to extract near-Earth SWCX signals from the XMM-Newton’s raw observation data. Then, we investigate the relation of near-Earth X-ray emissions to the solar irradiance, solar wind flux, and abundances of X-ray source particles in solar wind.


Friday, 25 Oct. 2019

Globe Room, Elvey Building