DOI: 10.1029/2018JA025339
Scopus记录号: 2-s2.0-85050279073
论文题名: Statistical Study of Mercury's Energetic Electron Events as Observed by the Gamma-Ray and Neutron Spectrometer Instrument Onboard MESSENGER
作者: Nikoukar R. ; Lawrence D.J. ; Peplowski P.N. ; Dewey R.M. ; Korth H. ; Baker D.N. ; McNutt R.L. ; Jr.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 6 起始页码: 4961
结束页码: 4978
语种: 英语
英文关键词: energetic electrons
; Mercury magnetosphere
英文摘要: We present results from a statistical analysis of Mercury's energetic electron (EE) events as observed by the gamma-ray and neutron spectrometer instrument onboard the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. The main objective of this study is to investigate possible anisotropic behavior of EE events using multiple data sets from MESSENGER instruments. We study the data from the neutron spectrometer (NS) and the gamma-ray spectrometer anticoincidence shield (ACS) because they use the same type of borated plastic scintillator and, hence, they have very similar response functions, and their large surface areas make them more sensitive to low-intensity EE events than MESSENGER's particle instrumentation. The combined analysis of NS and ACS data reveals two different classes of energetic electrons: “Standard” events and “ACS-enhanced” events. Standard events, which comprise over 90% of all events, have signal sizes that are the same in both the ACS and NS. They are likely gyrating particles about Mercury's magnetic field following a 90° pitch angle distribution and are located in well-defined latitude and altitude regions within Mercury's magnetosphere. ACS-enhanced events, which comprise less than 10% of all events, have signal sizes in the ACS that are 10 to 100 times larger than those observed by the NS. They follow a beam-like distribution and are observed both inside and outside Mercury's magnetosphere with a wider range of latitudes and altitudes than Standard events. The difference between the Standard and ACS-enhanced event characteristics suggests distinct underyling acceleration mechanisms. ©2018. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113728
Appears in Collections: 气候减缓与适应
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作者单位: Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, United States; Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, United States; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, United States
Recommended Citation:
Nikoukar R.,Lawrence D.J.,Peplowski P.N.,et al. Statistical Study of Mercury's Energetic Electron Events as Observed by the Gamma-Ray and Neutron Spectrometer Instrument Onboard MESSENGER[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(6)