Thumbnail
Access Restriction
Open

Author Mullen, P. D. ♦ Cumbee, R. S. ♦ Lyons, D. ♦ Shelton, R. L. ♦ Stancil, P. C. ♦ Gu, L. ♦ Kaastra, J.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ ASTROPHYSICS ♦ CARBON DIOXIDE ♦ CARBON MONOXIDE ♦ CHARGE EXCHANGE ♦ COLLISIONS ♦ COMETS ♦ CROSS SECTIONS ♦ ELECTRON CAPTURE ♦ ELECTRONS ♦ EMISSION ♦ IONS ♦ SIMULATION ♦ SOLAR WIND ♦ X RADIATION
Abstract Charge exchange (CX) has emerged in X-ray emission modeling as a significant process that must be considered in many astrophysical environments—particularly comets. Comets host an interaction between solar wind ions and cometary neutrals to promote solar wind charge exchange (SWCX). X-ray observatories provide astronomers and astrophysicists with data for many X-ray emitting comets that are impossible to accurately model without reliable CX data. Here, we utilize a streamlined set of computer programs that incorporate the multi-channel Landau–Zener theory and a cascade model for X-ray emission to generate cross sections and X-ray line ratios for a variety of bare and non-bare ion single electron capture (SEC) collisions. Namely, we consider collisions between the solar wind constituent bare and H-like ions of C, N, O, Ne, Na, Mg, Al, and Si and the cometary neutrals H{sub 2}O, CO, CO{sub 2}, OH, and O. To exemplify the application of this data, we model the X-ray emission of Comet C/2000 WM1 (linear) using the CX package in SPEX and find excellent agreement with observations made with the XMM-Newton RGS detector. Our analyses show that the X-ray intensity is dominated by SWCX with H, while H{sub 2}O plays a secondary role. This is the first time, to our knowledge, that CX cross sections have been implemented into a X-ray spectral fitting package to determine the H to H{sub 2}O ratio in cometary atmospheres. The CX data sets are incorporated into the modeling packages SPEX and Kronos .
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-07-20
Publisher Place United States
Journal Astrophysical Journal
Volume Number 844
Issue Number 1


Open content in new tab

   Open content in new tab