Coronal-Temperature-Diagnostic Capability of the Hinode/X-Ray Telescope Based on Self-Consistent Calibration

Narukage, Noriyuki; Sakao, Taro; Kano, Ryouhei; Hara, Hirohisa; Shimojo, Masataka; Bando, T.; Urayama, Fumitaka; DeLuca, E. E.; Golub, L.; Weber, Mark; Grigis, P. C.; Cirtain, Jonathan; Tsuneta, S.

doi:10.1007/s11207-010-9685-2

Cited by 74 publications

(77 citation statements)

References 31 publications

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“…This ratio is then the only one we used in further measurements. The estimated uncertainties computed using the error estimation given by Narukage et al (2011) are on the range 10-15%. The average jet temperatures are 1.8 ± 0.2 × 10 6 K, temperatures measured for single events are shown in Fig.…”

Section: Plasma Temperaturesmentioning

confidence: 99%

Physical properties of solar polar jets

Paraschiv

Бемпорад

Sterling

2015

A&A

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Aims. The target of this work is to investigate the physical nature of polar jets in the solar corona and their possible contribution to coronal heating and solar wind flow based on the analysis of X-ray images acquired by the Hinode XRT telescope. We estimate the different forms of energy associated with many of these small-scale eruptions, in particular the kinetic energy and enthalpy. Methods. Two Hinode XRT campaign datasets focusing on the two polar coronal holes were selected to analyze the physical properties of coronal jets; the analyzed data were acquired using a series of three XRT filters. Typical kinematical properties (e.g., length, thickness, lifetime, ejection rate, and velocity) of 18 jets are evaluated from the observed sequences, thus providing information on their possible contribution to the fast solar wind flux escaping from coronal holes. Electron temperatures and densities of polar-jet plasmas are also estimated using ratios of the intensities observed in different filters. Results. We find that the largest amount of energy eventually provided to the corona is thermal. The energy due to waves may also be significant, but its value is comparatively uncertain. The kinetic energy is lower than thermal energy, while other forms of energy are comparatively low. Lesser and fainter events seem to be hotter, thus the total contribution by polar jets to the coronal heating could have been underestimated so far. The kinetic energy flux is usually around three times smaller than the enthalpy counterpart, implying that this energy is converted into plasma heating more than in plasma acceleration. This result suggests that the majority of polar jets are most likely not escaping from the Sun and that only cooler ejections could possibly have enough kinetic energy to contribute to the total solar wind flow.

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Section: Plasma Temperaturesmentioning

confidence: 99%

Physical properties of solar polar jets

Paraschiv

Бемпорад

Sterling

2015

A&A

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“…These DEMs are then compared to those obtained from the EIS lines. Updated XRT filter calibrations were used (Narukage et al 2011). Also in this case we used the Markov-chain Monte Carlo (MCMC) based reconstruction algorithm (Kashyap & Drake 1998) and the four abundance datasets.…”

Section: Observations and Data Analysismentioning

confidence: 99%

Response of Hinode XRT to quiet Sun, active region and flare plasma

O’Dwyer¹,

Zanna²,

Mason³

2013

A&A

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Aims. We examine the response of the Hinode X-Ray Telescope (XRT), using simultaneous observations with the Hinode Extremeultraviolet Imaging Spectrometer (EIS), for a flare, an active region and a quiet Sun region. We also examine the relative intensity calibration of EIS and XRT. Methods. EIS differential emission measure distribution (DEM) curves were used to create synthetic spectra with the CHIANTI atomic database. The contribution of spectral lines and continuum emission to each of the XRT channels was determined from the synthetic spectra, which were then convolved with the effective area of each XRT channel. The predicted total count rates for each channel were compared with the observed count rates. The effects of varying elemental abundances and the temperature range for the inversion were investigated. DEMs obtained from the XRT bands were also computed and compared to those obtained with EIS.Results. For the active region observations, the observed XRT count rates for most of the channels are in reasonable agreement with those predicted using EIS observations, but are dependent on the elemental abundances chosen. Significant discrepancies between predicted and observed count rates were found and are discussed for the adjacent quiet Sun region and also for the flare. Synthetic spectra and continuum emission contributing to the XRT channels are presented and discussed for the active region, quiet Sun and flare observations.

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“…We generate maps of temperature T and volumetric emission measure EM at each pixel in the XRT FOV using the filter ratio method described in Narukage et al (2011). This analysis assumes an isothermal plasma.…”

Section: Temperature Emission Measure and Radiated Powermentioning

confidence: 99%

“…XRT suffers from a time-varying contamination that collects on the CCD, obscuring about 5% of the area in the form of condensation-formed spots (Narukage et al, 2011). While the locations of these spots are known, their wavelengthdependent opacities and time dependent thicknesses are not.…”

Section: Temperature Emission Measure and Radiated Powermentioning

confidence: 99%

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Quiescent Reconnection Rate Between Emerging Active Regions and Preexisting Field, with Associated Heating: NOAA AR 11112

et al. 2014

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When magnetic flux emerges from beneath the photosphere it displaces the preexisting field in the corona, and a current sheet generally forms at the boundary between the old and new magnetic domains. Reconnection in the current sheet relaxes this highly stressed configuration to a lower energy state. This scenario is most familiar, and most often studied, in flares, where the flux transfer is rapid. We present here a study of steady, quiescent flux transfer occurring at a rate three orders of magnitude below that in a large flare. In particular we quantify the reconnection rate, and related energy release, occurring as new polarity emerges to form Active Region 11112 (SOL16 October 2010T00:00:00L205C117) within a region of preexisting flux. A bright, low lying kernel of coronal loops above the emerging polarity, observed with the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory and the X-ray Telescope onboard Hinode, originally shows magnetic connectivity only between regions of newly emerged flux when overlaid on magnetograms from the Helioseisimic and Magnetic Imager. Over the course of several days, this bright kernel advances into the preexisting flux. The advancement of an easily visible boundary into the old flux regions allows measurement of the rate of reconnection between old and new magnetic domains. We compare the reconnection rate to the inferred heating of the coronal plasma. To our knowledge, this is the first measurement of steady, quiescent heating related to reconnection. We determine that the newly emerged flux reconnects at a fairly steady rate of 0.38 × 10 16 Mx s −1 over two days, while the radiated power varies between (2 ∼ 8) × 10 25 erg s −1 over the same time. We find that as much as 40% of the total emerged flux at any given time may have reconnected. The total amount of transferred flux (∼ 1 × 10 21 Mx) and radiated energy (∼ 7.2 × 10 30 ergs) are comparable to that of a large M-or small X-class flare, but are stretched out over 45 hours.

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Coronal-Temperature-Diagnostic Capability of the Hinode/X-Ray Telescope Based on Self-Consistent Calibration

Cited by 74 publications

References 31 publications

Physical properties of solar polar jets

Physical properties of solar polar jets

Response of Hinode XRT to quiet Sun, active region and flare plasma

Quiescent Reconnection Rate Between Emerging Active Regions and Preexisting Field, with Associated Heating: NOAA AR 11112

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