Magnetic flux cancellation associated with a recurring solar jet observed withHinode,RHESSI, andSTEREO/EUVI

Chifor, C.; Isobe, Hiroaki; Mason, H. E.; Hannah, I. G.; Young, Peter R.; Zanna, G. Del; Krucker, S.; Ichimoto, Kiyoshi; Katsukawa, Y.; Yokoyama, T.

doi:10.1051/0004-6361:200810265

Cited by 87 publications

(89 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This type of V image has been used to analyse the dynamic motions of magnetic elements in the photosphere (Otsuji et al 2007). In a way similar to Chae et al (2007) and Chifor et al (2008), we use the ratio V/I to calculate the line-of-sight magnetic field B LOS in a sub-area around the reconnection site. This B LOS magnetogram is found to be consistent with the scaled V image, which is scaled to the MDI magnetogram, assuming that the magnetic flux observed by MDI is equal to that observed by SOT.…”

Section: Data Calibration and Alignmentmentioning

confidence: 99%

Reconfiguration of the coronal magnetic field by means of reconnection driven by photospheric magnetic flux convergence

He¹,

Marsch²,

Tu³

et al. 2010

A&A

View full text Add to dashboard Cite

Context. Magnetic reconnection is commonly believed to be responsible for flare-like events and plasma ejections in the solar atmosphere, but the field-line reconfiguration observed in association with magnetic reconnection has rarely been observed before. Aims. We attempt to reconstruct the configuration of the magnetic field during a magnetic reconnection event, estimate the reconnection rate, and analyze the resulting X-ray burst and plasma ejection. Methods. We use the local-correlation-tracking (LCT) method to track the convergence of magnetic fields with opposite polarities using photospheric observations from SOT/Hinode. The magnetic field lines are then extrapolated from the tracked footpoint positions into the corona, and the changes in field-line connections are marked. We estimate the reconnection rate by calculating the convective electric field in the photosphere, which is normalized to the product of the plasma jet speed and the coronal magnetic field strength inside the inflow region. The observed X-ray burst and plasma ejection are analysed with data from XRT/Hinode and TRACE, respectively. Results. We find that in this reconnection event the two sets of approaching closed loops were reconfigured to a set of superimposed large-scale closed loops and another set of small-scale closed loops. Enhanced soft X-ray emission was seen to rapidly fill the reconnected loop after the micro-flare occurred at the reconnection site. Plasma was ejected from that site with a speed between 27 and 40 km s −1 . The reconnection rate is estimated to range between 0.03 and 0.09. Conclusions. Our work presents a study of the magnetic field reconfiguration owing to magnetic reconnection driven by flux convergence in the photosphere. This observation of the magnetic structure change is helpful for future diagnosis of magnetic reconnection. The results obtained for the reconnection rate, the X-ray emission burst, and the plasma ejection provides new observational evidence, and places constraints on future theoretical study of magnetic reconnection in the Sun.

show abstract

Section: Data Calibration and Alignmentmentioning

confidence: 99%

Reconfiguration of the coronal magnetic field by means of reconnection driven by photospheric magnetic flux convergence

He¹,

Marsch²,

Tu³

et al. 2010

A&A

View full text Add to dashboard Cite

show abstract

“…Several EUV jets repeatedly occurred in the active region where pre-existing magnetic flux was canceled by newly emerging flux of opposite polarity. Chifor et al (2008) analyzed a recurring solar active region jet that is observed in X-ray and EUV, finding a correlation between recurring magnetic cancellation and the X-ray jet emission. The jet emission was attributed to chromospheric evaporation flows due to recurring magnetic reconnection.…”

Section: Introductionmentioning

confidence: 99%

Blobs in recurring extreme-ultraviolet jets

Zhang

2014

A&A

View full text Add to dashboard Cite

Context. Coronal jets are one type of ubiquitous small-scale activity that is caused by magnetic reconnection in the solar corona. They are often associated with cool surges in the chromosphere. Aims. In this paper, we report our discovery of blobs in the recurrent and homologous jets that occurred at the western edge of the NOAA active region 11259 on 2011 July 22. Methods. The jets were observed in the seven extreme-ultraviolet (EUV) filters of the Atmospheric Imaging Assembly instrument aboard the Solar Dynamics Observatory. Using the base-difference images of the six filters (94, 131, 171, 211, 193, and 335 Å), we carried out the differential emission measure (DEM) analyses to explore the thermodynamic evolutions of the jets. The jets were accompanied by cool surges observed in the Hα line center of the ground-based telescope in the Big Bear Solar Observatory. Results. The jets that had lifetimes of 20−30 min recurred at the same place for three times with an interval of 40−45 min. Interestingly, each of the jets intermittently experienced several upward eruptions at the speed of 120−450 km s −1 . After reaching the maximum heights, they returned back to the solar surface, showing near-parabolic trajectories. The falling phases were more evident in the low-T filters than in the high-T filters, indicating that the jets experienced cooling after the onset of eruptions. We identified bright and compact blobs in the jets during their rising phases. The simultaneous presence of blobs in all the EUV filters were consistent with the broad ranges of the DEM profiles of the blobs (5.5 ≤ log T ≤ 7.5), indicating their multi-thermal nature. The median temperatures of the blobs were ∼2.3 MK. The blobs that were ∼3 Mm in diameter had lifetimes of 24−60 s. Conclusions. To our knowledge, this is the first report of blobs in coronal jets. We propose that these blobs are plasmoids created by the magnetic reconnection as a result of tearing-mode instability and are ejected out along the jets.

show abstract

“…They have been observed in various wavelengths (X-ray, EUV and Hα) by the instruments on board Yohkoh, Stereo and Hinode satellites (Shimojo et al 1996;Chae et al 1999;Chifor et al 2008a;Patsourakos et al 2008). Jets may appear recurrently (Chifor et al 2008b) over bright points and strong flows are measured along their length. These bright points, which often are associated with microflaring activity, may correspond to emerging magnetic flux from below the photosphere (Canfield et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Observations and 3D MHD simulations of a solar active region jet

Gontikakis¹,

Archontis

Tsinganos

2009

A&A

View full text Add to dashboard Cite

Aims. We study an active region jet originating from NOAA 8531 on May 15 1999. We perform 3D MHD numerical simulations of magnetic flux emergence and its subsequent reconnection with preexisting magnetic flux. Then, we compare the physical properties of the observed jet with the reconnecting outflow produced in the numerical model. Methods. We report observations of this jet using a series of TRACE 171 Å filtergrams, simultaneous observations from SUMER in Ne viii 770Å and C iv 1548 Å as well as MDI magnetograms. In the numerical simulation, the full compressible and resistive MHD equations are solved, including viscous and Ohmic heating. Results. A high-velocity upflow ( 100 km s −1 ) is observed after the emergence of new magnetic flux at the edge of the active region. The jet is recorded over a range of temperatures between 10 5 K and 1.5 × 10 6 K. In our numerical experiments, we find that the jet is the result of magnetic reconnection between newly emerging flux and the preexisting magnetic field of the active region. Conclusions. The hot and high-velocity bidirectional flows occur as a result of the interaction between oppositely directed magnetic fields. Observations and numerical results are strongly suggestive of effective reconnection process being responsible for producing jets when emerging flux appears in solar active regions.

show abstract

Magnetic flux cancellation associated with a recurring solar jet observed withHinode,RHESSI, andSTEREO/EUVI

Cited by 87 publications

References 43 publications

Reconfiguration of the coronal magnetic field by means of reconnection driven by photospheric magnetic flux convergence

Reconfiguration of the coronal magnetic field by means of reconnection driven by photospheric magnetic flux convergence

Blobs in recurring extreme-ultraviolet jets

Observations and 3D MHD simulations of a solar active region jet

Contact Info

Product

Resources

About