@article{9ea18d474d00450588b9009878ce1eca,
title = "The origin of the local 1/4-keV X-ray flux in both charge exchange and a hot bubble",
abstract = "The solar neighbourhood is the closest and most easily studied sample of the Galactic interstellar medium, an understanding of which is essential formodels of star formation and galaxy evolution.Observations of an unexpectedly intense diffuse flux of easily absorbed 1/4-kiloelectronvolt X-rays 1,2, coupled with the discovery that interstellar space within about a hundredparsecs of the Sun is almost completely devoid of cool absorbing gas3, led to a picture of a 'local cavity' filled with X-ray-emitting hot gas, dubbed the local hot bubble4-6. This model was recently challenged by suggestions that the emission could instead be readily produced within the Solar System by heavy solar-wind ions exchanging electrons with neutralHandHein interplanetary space7-11, potentially removing themajor piece of evidence for the local existence of million-degree gas within the Galactic disk12-15. Here we report observations showing that the total solarwind charge-exchange contribution is approximately 40 per cent of the 1/4-keV flux in the Galactic plane. The fact that the measured flux is not dominated by charge exchange supports the notion of a million-degree hot bubble extending about a hundred parsecs from the Sun.",
author = "M. Galeazzi and M. Chiao and Collier, {M. R.} and T. Cravens and D. Koutroumpa and Kuntz, {K. D.} and R. Lallement and Lepri, {S. T.} and D. McCammon and K. Morgan and Porter, {F. S.} and Robertson, {I. P.} and Snowden, {S. L.} and Thomas, {N. E.} and Y. Uprety and E. Ursino and Walsh, {B. M.}",
note = "Funding Information: Acknowledgements We thank the personnel at NASA{\textquoteright}s Wallops Flight Facility and the White Sands Military Range for their support of payload development, integration and launch, and the technical personnel at the University of Miami, NASA{\textquoteright}s Goddard Space Flight Center and the University of Michigan for their support of the instrument{\textquoteright}s development. This work was supported by NASA award numbers NNX11AF04G and NNX09AF09G. D.K. and R.L. acknowledge financial support for their activity through the programme {\textquoteleft}Soleil H{\'e}liosph{\`e}re Magn{\'e}tosph{\`e}re{\textquoteright} of the French space agency CNES, and the National Program {\textquoteleft}Physique Chimie du Milieu Interstellaire{\textquoteright} of the Institut National des Sciences de l{\textquoteright}Univers (INSU). M.C. and N.E.T. are employed through the Center for Research and Exploration in Space Science and Technology (CRESST) and the University of Maryland, Baltimore County, Baltimore, Maryland, USA.",
year = "2014",
month = aug,
day = "14",
doi = "10.1038/nature13525",
language = "English (US)",
volume = "512",
pages = "171--173",
journal = "Nature",
issn = "0028-0836",
publisher = "Nature Publishing Group",
number = "7513",
}