Abstract
We wished to analyse a sample of observations from the XMM-Newton Science Archive to search for evidence of exospheric solar wind charge exchange (SWCX) emission. We analysed 3012 observations up to and including revolution 1773. The method employed extends from that of the previously published paper by these authors on this topic. We detect temporal variability in the diffuse X-ray background within a narrow low-energy band and contrast this to a continuum. The low-energy band was chosen to represent the key indicators of charge exchange emission and the continuum was expected to be free of SWCX. Approximately 3.4 % of observations studied are affected. We discuss our results with reference to the XMM-Newton mission. We further investigate remarkable cases by considering the state of the solar wind and the orientation of XMM-Newton at the time of these observations. We present a method to approximate the expected emission from observations, based on given solar wind parameters taken from an upstream solar wind monitor. We also compare the incidence of SWCX cases with solar activity. We present a comprehensive study of the majority of the suitable and publically available XMM-Newton Science Archive to date, with respect to the occurrence of SWCX enhancements. We present our SWCX-affected subset of this dataset. The mean exospheric-SWCX flux observed within this SWCX-affected subset was 15.4 keV cm-2 s-1 sr-1 in the energy band 0.25 to 2.5 keV. Exospheric SWCX is preferentially detected when XMM-Newton observes through the subsolar region of the Earth's magnetosheath. The model developed to estimate the expected emission returns fluxes within a factor of a few of the observed values in the majority of cases, with a mean value at 83 %.
Highlights
This paper follows that of Carter & Sembay (2008), whereby a set of approximately 180 XMM-Newton observations, taken between revolutions 52 and 1104 (March 2000 until December 2005), were analysed to search for cases of solar wind charge exchange emission (SWCX) occurring within the Earth’s magnetosheath or in near interplanetary space
This paper extends the work of Paper I, to provide a complete sample, covering 3012 suitable XMM-Newton observations downloaded from the XMM-Newton Science Archive (XSA)1
We have identified 103 XMM-Newton observations, 3.4% of the sample studied, when temporally variable SWCX emission was present in the data
Summary
This paper follows that of Carter & Sembay (2008) (hereafter Paper I), whereby a set of approximately 180 XMM-Newton observations, taken between revolutions 52 and 1104 (March 2000 until December 2005), were analysed to search for cases of solar wind charge exchange emission (SWCX) occurring within the Earth’s magnetosheath or in near interplanetary space. During various periods of its orbit and depending on observational constraints, XMM-Newton may view regions of the Earth’s magnetosheath which are predicted to exhibit the highest X-ray emissivity due to SWCX between highly charged solar wind ions and hydrogen in the Earth’s exosphere (Robertson et al 2006, and references therein).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
