The Structure of the Local Hot Bubble

TL;DR

This study uses data from the DXL mission to separate Solar Wind Charge eXchange effects from X-ray background, enabling detailed analysis of the Local Hot Bubble's temperature and structure.

Contribution

It provides the first quantification of SWCX contribution to the diffuse X-ray background and maps the 3D structure of the LHB using cleaned X-ray data.

Findings

LHB temperature is approximately 0.097 keV with low variation.

The 3D structure of the LHB aligns with local dust and gas measurements.

SWCX contribution was successfully quantified and removed from X-ray data.

Abstract

DXL (Diffuse X-rays from the Local Galaxy) is a sounding rocket mission designed to quantify and characterize the contribution of Solar Wind Charge eXchange (SWCX) to the Diffuse X-ray Background and study the properties of the Local Hot Bubble (LHB). Based on the results from the DXL mission, we quantified and removed the contribution of SWCX to the diffuse X-ray background measured by the ROSAT All Sky Survey (RASS). The "cleaned" maps were used to investigate the physical properties of the LHB. Assuming thermal ionization equilibrium, we measured a highly uniform temperature distributed around kT=0.097 keV+/-0.013 keV (FWHM)+/-0.006 keV (systematic). We also generated a thermal emission measure map and used it to characterize the three-dimensional (3D) structure of the LHB which we found to be in good agreement with the structure of the local cavity measured from dust and gas.