New Measurement of the Vertical Atmospheric Density Profile from Occultations of the Crab Nebula with X-Ray Astronomy Satellites Suzaku and Hitomi

Abstract

Combined O and N densities at altitudes 70-200 km are measured from Earth occultations of the Crab Nebula using X-ray astronomy satellites, Suzaku and Hitomi.• The vertical density profile is in general agreement with a predicted profile from the NRLMSISE-00 model, except for altitudes 70-110 km in which the density is significantly smaller than the prediction by the NRL model.• This density deficit could be due to either long-term radiative cooling of the upper atmosphere or imperfect modeling.

Long‐Term Density Trend in the Mesosphere and Lower Thermosphere From Occultations of the Crab Nebula With X‐Ray Astronomy Satellites

“…Recently, Katsuda et al. (2021), hereafter Paper I, and Yu et al. (2022a, 2022b) applied the same technique to derive atmospheric vertical density profiles, using Japanese and Chinese X‐ray astronomy satellites, respectively.…”