Regular Pulses from the Sun and a Possible Clue to the Origin of Solar Cosmic Rays

McLean, D. J.; Sheridan, K. V.; Stewart, R. T.; Wild, John

doi:10.1038/234140a0

Cited by 99 publications

(29 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A number of publications (Abrami, 1970(Abrami, , 1972Rosenberg, 1970Rosenberg, , 1972McLean et al, 1971) have already described the remarkably regular trains of pulses sometimes received from the Sun at metre wavelengths during solar radio outbursts. We wish to present here a particularly striking, recent example of this phenomenon, and to draw attention to the difficulties encountered in the application of existing theories to this event.…”

Section: Introductionmentioning

confidence: 99%

A damped train of regular metre-wave pulses from the sun

McLean

Sheridan

1973

Sol Phys

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

A damped train of regular metre-wave pulses from the sun

McLean

Sheridan

1973

Sol Phys

Self Cite

View full text Add to dashboard Cite

show abstract

“…Melnikov et al 2005;Inglis et al 2008;Nakariakov 2007;Nakariakov & Melnikov 2009;Zimovets & Struminsky 2009), although in a few cases harmonic oscillations of persistent amplitude and duration have been detected (see, e.g. McLean et al 1971;Kislyakov et al 2006). Moreover, QPP are often detected with several independent and spatially separated instruments, not only in hard X-rays and microwaves, but also at sub-millimeter wavelengths (Kaufmann et al 2009;Fleishman & Kontar 2010) and in soft X-rays (see Mariska 2005Mariska , 2006, where a large number of Doppler shift oscillations during flares were studied using Yohkoh's Bragg Crystal Spectrometer (BCS)).…”

Section: Introductionmentioning

confidence: 99%

Instrumental oscillations in RHESSI count rates during solar flares

Inglis

Zimovets

Dennis

et al. 2011

A&A

View full text Add to dashboard Cite

Aims. We seek to illustrate the analysis problems posed by RHESSI spacecraft motion by studying persistent instrumental oscillations found in the lightcurves measured by RHESSI's X-ray detectors in the 6-12 keV and 12-25 keV energy range during the decay phase of the flares of 2004 November 4 and 6. Methods. The various motions of the RHESSI spacecraft which may contribute to the manifestation of oscillations are studied. The response of each detector in turn is also investigated. Results. We find that on 2004 November 6 the observed oscillations correspond to the nutation period of the RHESSI instrument. These oscillations are of greatest amplitude for detector 5, while in the lightcurves of many other detectors the oscillations are small or undetectable. We also find that the variation in detector pointing is much larger during this flare than the counterexample of 2004 November 4. Conclusions. Sufficiently large nutation motions of the RHESSI spacecraft lead to clearly observable oscillations in count rates, posing a significant hazard for data analysis. This issue is particularly problematic for detector 5 due to its design characteristics. Dynamic correction of the RHESSI counts, accounting for the livetime, data gaps, and the transmission of the bi-grid collimator of each detector, is required to overcome this issue. These corrections should be applied to all future oscillation studies.

show abstract

“…Several types of pulsation phenomena have been noted. At meter wavelengths (m-k) certain type IV and moving type IV radio bursts produce exceptionally regular and deeply modulated pulsations with bandwidths Áf /f > 1 (Abrami 1970(Abrami , 1972Rosenberg 1970Rosenberg , 1972McLean et al 1971;McLean & Sheridan 1973;Trottet et al 1981;Karlický & Bárta 2007). At m-k and decimeter wavelengths (dm-k), rapid QPPs occur with periods of tens to hundreds of ms.…”

Section: Introductionmentioning

confidence: 99%

Broadband Quasi‐periodic Radio and X‐Ray Pulsations in a Solar Flare

Fleishman

Bastian

Gary

2008

Astrophysical Journal

View full text Add to dashboard Cite

We describe microwave and hard X-ray observations of strong quasi-periodic pulsations from the GOES X1.3 solar flare on 2003 June 15. The radio observations were made jointly by the Owens Valley Solar Array (OVSA), the Nobeyama Polarimeter (NoRP), and the Nobeyama Radioheliograph (NoRH ). Hard X-ray observations were made by RHESSI. Using Fourier analysis, we study the frequency-and energy-dependent oscillation periods, differential phase, and modulation amplitudes of the radio and X-ray pulsations. Focusing on the more complete radio observations, we also examine the modulation of the degree of circular polarization and of the radio spectral index. The observed properties of the oscillations are compared with those derived from two simple models for the radio emission. In particular, we explicitly fit the observed modulation amplitude data to the two competing models. The first model considers the effects of MHD oscillations on the radio emission. The second model considers the quasiperiodic injection of fast electrons. We demonstrate that quasi-periodic acceleration and injection of fast electrons is the more likely cause of the quasi-periodic oscillations observed in the radio and hard X-ray emission, which has important implications for particle acceleration and transport in the flaring sources.

show abstract

Regular Pulses from the Sun and a Possible Clue to the Origin of Solar Cosmic Rays

Cited by 99 publications

References 5 publications

A damped train of regular metre-wave pulses from the sun

A damped train of regular metre-wave pulses from the sun

Instrumental oscillations in RHESSI count rates during solar flares

Broadband Quasi‐periodic Radio and X‐Ray Pulsations in a Solar Flare

Contact Info

Product

Resources

About