Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2010-05-28
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
13 pages, 18 figures
Scientific paper
Context: It is thought likely that vast numbers of nanoflares are responsible for the corona having a temperature of millions of degrees. Current observational technologies lack the resolving power to confirm the nanoflare hypothesis. An alternative approach is to construct a magnetohydrodynamic coronal loop model that has the ability to predict nanoflare energy distributions. Aims: This paper presents the initial results generated by such a model. It predicts heating events with a range of sizes, depending on where the instability threshold for linear kink modes is encountered. The aims are to calculate the distribution of event energies and to investigate whether kink instability can be predicted from a single parameter. Methods: The loop is represented as a straight line-tied cylinder. The twisting caused by random photospheric motions is captured by two parameters, representing the ratio of current density to field strength for specific regions of the loop. Dissipation of the loop's magnetic energy begins during the nonlinear stage of the instability, which develops as a consequence of current sheet reconnection. After flaring, the loop evolves to the state of lowest energy where, in accordance with relaxation theory, the ratio of current to field is constant throughout the loop and helicity is conserved. Results: The results suggest that instability cannot be predicted by any simple twist-derived property reaching a critical value. The model is applied such that the loop undergoes repeated episodes of instability followed by energy-releasing relaxation. Hence, an energy distribution of the nanoflares produced is collated. Conclusions: The final energy distribution features two nanoflare populations that follow different power laws. The power law index for the higher energy population is more than sufficient for coronal heating.
Bareford Michael R.
Browning Philippa K.
der Linden Ronald A. M. Van
No associations
LandOfFree
A Nanoflare Distribution Generated by Repeated Relaxations Triggered by Kink Instability does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Nanoflare Distribution Generated by Repeated Relaxations Triggered by Kink Instability, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Nanoflare Distribution Generated by Repeated Relaxations Triggered by Kink Instability will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-15814