DIAGNOSTICS ON THE SOURCE PROPERTIES OF A TYPE II RADIO BURST WITH SPECTRAL BUMPS

Journal Article · Wed Apr 10 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/767/1/29· OSTI ID:22167446

Feng, S. W.; Chen, Y.; Kong, X. L.; Li, G.; Song, H. Q. ^[1]; Feng, X. S. ^[2]; Guo, Fan ^[3]

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1. Institute of Space Sciences and School of Space Science and Physics, Shandong University, Weihai 264209 (China)
2. SIGMA Weather Group, State Key laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)
3. Department of Planetary Sciences and Lunar and Planetary laboratory, University of Arizona, Tucson, AZ 85721 (United States)

In recent studies, we proposed that source properties of type II radio bursts can be inferred through a causal relationship between the special shape of the type II dynamic spectrum (e.g., bump or break) and simultaneous extreme ultraviolet (EUV)/white light imaging observations (e.g., CME-shock crossing streamer structures). As a further extension of these studies, in this paper we examine the coronal mass ejection (CME) event on 2007 December 31 associated with a multiple type II radio burst. We identify the presence of two spectral bump features on the observed dynamic spectrum. By combining observational analyses of the radio spectral observations and the EUV-white light imaging data, we conclude that the two spectral bumps result from a CME-shock propagating across dense streamers on the southern and northern sides of the CME. It is inferred that the corresponding two type II emissions originate separately from the two CME-shock flanks where the shock geometries are likely quasi-perpendicular or oblique. Since the emission lanes are bumped as a whole within a relatively short time, it suggests that the type II radio bursts with bumps of this study are emitted from spatially confined sources (with a projected lateral dimension smaller than 0.05-0.1 R{sub Sun} at a fundamental frequency level of 20-30 MHz).

• OSTI ID: 22167446
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 767; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMIC X-RAY BURSTS
EMISSION
EXTREME ULTRAVIOLET RADIATION
GEOMETRY
MASS
MHZ RANGE
SHOCK WAVES
SPECTRA
SUN
VISIBLE RADIATION