Contributed Talk - Splinter eROSITA

Wednesday, 14 September 2022, 16:15   (SFG 0140 / virtual eROSITA)

The Soft X-Ray Foreground as Revealed by Sight Lines to the Darkest X-Ray Shadows

M. Yeung (1), M. Freyberg (1), G. Ponti (1,2)
(1) Max-Planck-Institut für extraterrestrische Physik, (2) INAF-Osservatorio Astronomico di Brera

SRG/eROSITA is situated in a halo orbit around L2 where the highly variable solar wind charge exchange (SWCX) from Earth's magnetosheath is expected to be minimal. The soft X-ray foreground emissions from the Local Hot Bubble (LHB) and the remaining heliospheric SWCX emissions could be studied in unprecedented detail with eROSITA All-Sky Survey (eRASS) data in 6-month cadence and better spectral resolution. Giant molecular clouds located at the edge of the LHB provide the best sight lines for such study as most of the background emission is absorbed to reveal the foreground. Combining with the distance to the clouds, one could constrain and calibrate the density of the LHB for future all-sky studies. I will present the key findings from the detailed spectral analysis of these sight lines, including the properties and uniformity of the LHB, and the spatial and temporal variations in the SWCX level detected by eROSITA during the first four eRASSs.