Invited Article: First Flight in Space of a Wide-Field-of-View Soft X-Ray Imager Using Lobster-Eye Optics: Instrument Description and Initial Flight Results

We describe the development, launch into space, and initial results from a prototype wide eld-of-view (FOV) soft X-ray imager that employs Lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The Sheath Transport Observer for the Redistribution of Mass (STORM) is the rst instrument using this type of optics launched into space and provides proof-of-concept for future ight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the moon, and the solar wind interaction with planetary bodies like Venus and Mars

X-ray Emission from the Local Hot Bubble and Solar Wind Charge Exchange

DXL (Diffuse X-rays from the Local galaxy) is a sounding rocket mission to quantify the Solar Wind Charge Exchange (SWCX) X-ray emission in the interplanetary medium, and separate its contribution from the Local Hot Bubble (LHB) emission. The first launch of DXL took place in December 2012. This thesis will describe the DXL instrumentation and calibrations, and discuss the results obtained. The mission uses two large area proportional counters to scan through the Helium Focusing Cone (HFC), a high helium density region in the solar system emitting excess X-rays due to SWCX. Using well determined models of the interplanetary neutral distribution and comparing the DXL results with data from the same region obtained by the ROSAT satellite away from the cone, we calculated that SWCX contributes at most 36% to the ¼ keV ROSAT band and 13% to the ¾ keV ROSAT band, in the galactic plane. This provides a firm proof for existence of a LHB which dominates the Diffuse X-ray Background (DXB) at ¼ keV, while raising new questions on the origin of the ¾ keV emission

The Diffuse X-rays from the Local Galaxy (DXL) Mission

International audienceThe Diffuse X-rays from the Local Galaxy (DXL) mission is a sounding rocket mission for the study of Solar Wind Charge eXchange (SWCX) and Local Hot Bubble (LHB) X-ray emission. The mission was successfully launched from White Sands Missile Range, NM on December 12, 2012. It carried two large area proportional counters with thin carbon windows with roughly 1,000 cm2 area both in the ¼ and ¾ keV band. The mission successfully detected the spatial variation of the SWCX due to the He focusing cone. In this paper we will review the mission design and performance and present preliminary results from the December launch

The structure of the local hot bubble

International audienceDXL (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

The origin of the “local” ¼ keV X-ray flux

International audienceThe Solar Wind interacts with interstellar neutrals via charge exchange producing a spatially and temporally varying x-ray flux difficult to separate from other diffuse sources. The Diffuse X-rays from the Local Galaxy (DXL) mission measured the spatial signature of Solar Wind Charge eXchange (SWCX) emission using 2 large-area proportional counters. DXL was able to separate the SWCX contribution from the more dominant flux originating in the Local Hot Bubble. The data from the mission provide a robust estimate of the SWCX contribution to the RASS data in the ¼ keV band, showing that the total SWCX contribution is 40%±5% (stat) ±5% (sys) of the minimal ¼ keV flux in the Galactic plane. This result implies that the measured fluxes are dominated by interstellar emission, strengthening the idea of a hot bubble filling the cavity in the local interstellar medium extending ~50-150 pc from the Sun. Combined with recent three-dimensional maps of the local interstellar medium and Voyager measurements of the magnetic field outside the heliosphere, it also leads to a consistent picture of the local interstellar environment

The DXL and STORM sounding rocket mission

International audienc