Abstract
<p><span style="font-size: 18px;">The observed Diffuse X-ray Background (DXB) is made of different components that are difficult to separate because of similar observational properties. At very low energy, two local components are predominant, emission from the Local Hot Bubble (LHB), a 1M K plasma surrounding the solar system 100-300 pc in all directions, and Solar Wind Charge eXchange (SWCX), produced when solar wind ions interact with neutral gas in the interplanetary medium. The “Diffuse X-ray emission from the Local galaxy” (DXL) mission consists of a series of sounding rocket launches to study and separate the SWCX and LHB x-ray emissions. DXL-2 launched in December 2015 and used four large area proportional counters carrying three unique filters (carbon, boron, and beryllium-based). It scanned through the Helium Focusing Cone (HFC) in two perpendicular directions to look for the spatial signature of SWCX on top of the LHB emission. We find that the SWCX contribution to the diffuse x-ray background for the ¼ keV band in the galactic plane to be 30±6% and an average over the whole sky to be 30±6% the rest of the emission is dominated by LHB. Similarly, for ¾ keV we find it to be 21±9% in-plane and 14±6% for the whole sky. We used the observation along the ecliptic longitude to measure the pointing direction of the Sun’s velocity vector, which we quantify to be </span><span style="font-family: "Times New Roman", serif;"><span style="font-size: 18px;">λ= </span></span><span style="font-size: 18px;">73.5±3.6°. We extrapolate our result to identify SWCX and its </span><span style="font-size: 18px;">contribution to ROSAT All Sky Survey (RASS) maps and to derive physical parameters of the LHB. Our results will stand as a strong probe to correct for the embedded SWCX offset for any of the past or future observations on diffuse x-ray emission.</span></p>