Identification and analysis of structures in the corona from X-ray photography

Vaiana, G. S.; Krieger, A. S.; Timothy, A. F.

doi:10.1007/bf00152731

Cited by 272 publications

(95 citation statements)

References 15 publications

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“…The simple isothermal/ratio approach (e.g. Vaiana et al 1973) places a very strict, though possibly erroneous, constraint on the DEM solutions and so it is ill-suited to this problem. An alternative is to forward fit a chosen DEM model to the data, for example with multi-Gaussians (e.g.…”

Section: Introductionmentioning

confidence: 99%

Multi-thermal dynamics and energetics of a coronal mass ejection in the low solar atmosphere

Hannah

Kontar

2013

A&A

101

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Aims. The aim of this work is to determine the multi-thermal characteristics and plasma energetics of an eruptive plasmoid and occulted flare observed by the Solar Dynamics Observatory's Atmospheric Imaging Assembly (SDO/AIA). Methods. We study a 2010 Nov. 3 event (peaking at 12:20 UT in GOES soft X-rays) of a coronal mass ejection and occulted flare that demonstrates the morphology of a classic erupting flux rope. The high spatial and time resolution and six coronal channels of the SDO/AIA images allows the dynamics of the multi-thermal emission during the initial phases of eruption to be studied in detail. The differential emission measure is calculated, using an optimized version of a regularized inversion method, for each pixel across the six channels at different times, resulting in emission measure maps and movies in a variety of temperature ranges. Results. We find that the core of the erupting plasmoid is hot (8-11, 11-14 MK) with a similarly hot filamentary "stem" structure connecting it to the lower atmosphere, which could be interpreted as the current sheet in the flux rope model, though is wider than these models suggest. The velocity of the leading edge of the eruption is 597-664 km s −1 in the temperature range ≥3-4 MK and between 1029-1246 km s −1 for ≤2-3 MK. We estimate the density (in 11-14 MK) of the erupting core and stem during the impulsive phase to be about 3 × 10 9 cm −3 , 6 × 10 9 cm −3 , 9 × 10 8 cm −3 in the plasmoid core, stem, and surrounding envelope of material. This gives thermal energy estimates of 5 × 10 29 erg, 1 × 10 29 erg, and 2 × 10 30 erg. The kinetic energy for the core and envelope is slightly lower. The thermal energy of the core and current sheet grows during the eruption, suggesting continuous influx of energy presumably via reconnection. Conclusions. The combination of the optimized regularized inversion method and SDO/AIA data allows the multi-thermal characteristics (i.e. velocity, density, and thermal energies) of the plasmoid eruption to be determined.

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Section: Introductionmentioning

confidence: 99%

Multi-thermal dynamics and energetics of a coronal mass ejection in the low solar atmosphere

Hannah

Kontar

2013

A&A

101

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“…[2] In the solar corona, plasmas are confined by the magnetic field as shown in the soft X-ray solar images [Vaiana et al, 1973;Vaiana and Rosner, 1978;Tsuneta et al, 1992;Reale et al, 2007], the extreme ultraviolet (EUV) solar images [Sheeley et al, 1975;Moses et al, 1997;Schrijver et al, 1999;Wiegelmann et al, 2009], as well as the total solar eclipse coronal images [Pasachoff, 2009a[Pasachoff, , 2009bPasachoff et al, 2009]. Trapped plasmas above solar active regions form the coronal loops which reflect the shapes of the field lines [Krieger et al, 1971].…”

Section: Introductionmentioning

confidence: 99%

Nonlinear force-free field extrapolation of the coronal magnetic field using the data obtained by the Hinode satellite

Wang

Yan

2011

J. Geophys. Res.

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[1] The Hinode satellite can obtain high-quality photospheric vector magnetograms of solar active regions and the simultaneous coronal loop images in soft X-ray and extreme ultraviolet (EUV) bands. In this paper, we continue the work of and apply the newly developed upward boundary integration computational scheme for the nonlinear force-free field (NLFFF) extrapolation of the coronal magnetic field to the

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“…In this energy range the solar emission is mostly due to the continuum and lines emitted by the highly ionized constituents of the hot coronal plasma. On the high quality pictures the corona appears highly structured and the structures appear to be the result of dispersed active region magnetic fields (19), (20). Numerous 'bright points' are uniformly distributed across the solar surface (21).…”

Section: A Skylabmentioning

confidence: 99%

44. Astronomical Observations From Outside The Terrestrial Atmosphere

Code¹

1976

Trans. Int. Astron. Union

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Commission 44 is by title technique oriented. The following statement of the role of the commission was prepared for use by the General Secretary in responding to requests by non-astronomers with respect to the activities of IAU commissions.‘The Earth’s atmosphere is opaque to radiation throughout most of the electromagnetic spectrum. The light reaching the surface of the Earth from celestial objects is confined primarily to the visual region of the spectrum and a larger window in the radio region. Much of the infrared and all the far ultraviolet, X-ray and γ-ray radiation are absorbed in the upper atmosphere. Thus astronomers must carry their telescopes and auxiliary instrumentation above the Earth’s atmosphere to unlock the clues on the structure of the universe revealed by the light at these wavelengths. Furthermore the light in the accessible region of the spectrum that does reach the surface of the Earth is distorted and scattered in such a manner that the spatial resolution and details of the radiating source is seriously degraded.

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Identification and analysis of structures in the corona from X-ray photography

Cited by 272 publications

References 15 publications

Multi-thermal dynamics and energetics of a coronal mass ejection in the low solar atmosphere

Multi-thermal dynamics and energetics of a coronal mass ejection in the low solar atmosphere

Nonlinear force-free field extrapolation of the coronal magnetic field using the data obtained by the Hinode satellite

44. Astronomical Observations From Outside The Terrestrial Atmosphere

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