Solar Dynamics Observatory and Hinode Observations of a Blowout Jet in a Coronal Hole

Young, Peter R.; Muglach, K.

doi:10.1007/s11207-014-0484-z

Cited by 84 publications

(59 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More recently, Nisticò et al (2011) have described the typical physical characteristics of coronal jets observed by the SECCHI instruments of STEREO spacecraft obtaining a temperature determination for the jet plasma. Their results show that jets are characterized by electron temperatures ranging between 0.8 MK and 1.3 MK, similar to results by Young & Muglach (2014), who studied the link between a blowout jet and its base brightpoint. Pucci et al (2013) analyzed the difference between a standard and a blowout jet seen from Hinode-XRT.…”

Section: Introductionsupporting

confidence: 85%

Physical properties of solar polar jets

Paraschiv

Бемпорад

Sterling

2015

A&A

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionsupporting

confidence: 85%

Physical properties of solar polar jets

Paraschiv

Бемпорад

Sterling

2015

A&A

View full text Add to dashboard Cite

show abstract

“…Hence more energy can be transmitted to the plasma as the waves propagate upward, leading to even greater acceleration for nearly axisymmetric configurations. This could explain the nearly constant acceleration with height observed in some events (Patsourakos et al 2008;Young & Muglach 2014b). Our model predicts that nearly axisymmetric systems will not generate a strong standard jet before initiating a blowout jet.…”

Section: Observational Implicationsmentioning

confidence: 72%

Model for straight and helical solar jets

Pariat

Dalmasse

DeVore

et al. 2015

A&A

124

146

View full text Add to dashboard Cite

Context. Jets are dynamic, impulsive, well-collimated plasma events developing at many different scales and in different layers of the solar atmosphere. Aims. Jets are believed to be induced by magnetic reconnection, a process central to many astrophysical phenomena. Studying their dynamics can help us to better understand the processes acting in larger eruptive events (e.g., flares and coronal mass ejections) as well as mass, magnetic helicity, and energy transfer at all scales in the solar atmosphere. The relative simplicity of their magnetic geometry and topology, compared with larger solar active events, makes jets ideal candidates for studying the fundamental role of reconnection in energetic events. Methods. In this study, using our recently developed numerical solver ARMS, we present several parametric studies of a 3D numerical magneto-hydrodynamic model of solar-jet-like events. We studied the impact of the magnetic field inclination and photospheric field distribution on the generation and properties of two morphologically different types of solar jets, straight and helical, which can account for the observed so-called standard and blowout jets. Results. Our parametric studies validate our model of jets for different geometric properties of the magnetic configuration. We find that a helical jet is always triggered for the range of parameters we tested. This demonstrates that the 3D magnetic null-point configuration is a very robust structure for the energy storage and impulsive release characteristic of helical jets. In certain regimes determined by magnetic geometry, a straight jet precedes the onset of a helical jet. We show that the reconnection occurring during the straight-jet phase influences the triggering of the helical jet. Conclusions. Our results allow us to better understand the energization, triggering, and driving processes of straight and helical jets. Our model predicts the impulsiveness and energetics of jets in terms of the surrounding magnetic field configuration. Finally, we discuss the interpretation of the observationally defined standard and blowout jets in the context of our model, as well as the physical factors that determine which type of jet will occur.

show abstract

“…It is clear that, the temperature at the region of the footpoint is increased from log T [K] = 6.3 to log T [K] = 6.5. DEM measurements beyond log T [K] = 7 are not reliable due to the uncertainty in the contribution of emission lines to the AIA 94 and 131 Å channels (Young & Muglach 2014b). .0, 6.3 and 6.6) at 17:25 UT.…”

Section: August 02mentioning

confidence: 99%

Multiwavelength study of 20 jets that emanate from the periphery of active regions

Mulay

Tripathi

Zanna

et al. 2016

A&A

View full text Add to dashboard Cite

Aims. We present a multiwavelength analysis of 20 EUV jets which occurred at the periphery of active regions close to sunspots. We discuss the physical parameters of the jets and their relation with other phenomena such as Hα surges, nonthermal type-III radio bursts and hard X-ray (HXR) emission. Methods. These jets were observed between August 2010 and June 2013 by the Atmospheric Imaging Assembly (AIA) instrument that is onboard the Solar Dynamic Observatory (SDO). We selected events that were observed on the solar disk within +/-60• latitude. Using AIA wavelength channels that are sensitive to coronal temperatures, we studied the temperature distribution in the jets using the line of sight (LOS) differential emission measure (DEM) technique. We also investigated the role of the photospheric magnetic field using the LOS magnetogram data from the Helioseismic and Magnetic Imager (HMI) onboard SDO. Results. It has been observed that most of the jets originated from the western periphery of active regions. Their lifetimes range from 5 to 39 min with an average of 18 min and their velocities range from 87 to 532 km s −1 with an average of 271 km s −1 . All the jets are co-temporally associated with Hα surges. Most of the jets are co-temporal with nonthermal type-III radio bursts observed by the Wind/WAVES spacecraft in the frequency range from 20 kHz to 13 MHz. We confirm the source region of these bursts using the potential field source surface (PFSS) technique. Using Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations, we found that half of the jets produced HXR emission and they often shared the same source region as the HXR emission (6−12 keV). Ten out of 20 events showed that the jets originated in a region of flux cancellation and six jets in a region of flux emergence. Four events showed flux emergence and then cancellation during the jet evolution. DEM analyses showed that for most of the spires of the jets, the DEM peaked at around log T [K] = 6.2/6.3 (∼2 MK). In addition, we derived an emission measure and a lower limit of electron density at the location of the spire (jet 1: log EM = 28.6, N e = 1.3 × 10 10 cm −3 ; jet 2: log EM = 28.0, N e = 8.6 × 10 9 cm −3 ) and the footpoint (jet 1 -log EM = 28.6, N e = 1.1 × 10 10 cm −3 ; jet 2: log EM = 28.1, N e = 8.4 × 10 9 cm −3 ). These results are in agreement with those obtained earlier by studying individual active region jets. Conclusions. The observation of flux cancellation, the association with HXR emission and emission of nonthermal type-III radio bursts, suggest that the initiation and therefore, heating is taking place at the base of the jet. This is also supported by the high temperature plasma revealed by the DEM analysis in the jet footpoint (peak in the DEM at log T [K] = 6.5). Our results provide substantial constraints for theoretical modeling of the jets and their thermodynamic nature.

show abstract

Solar Dynamics Observatory and Hinode Observations of a Blowout Jet in a Coronal Hole

Cited by 84 publications

References 29 publications

Physical properties of solar polar jets

Physical properties of solar polar jets

Model for straight and helical solar jets

Multiwavelength study of 20 jets that emanate from the periphery of active regions

Contact Info

Product

Resources

About