Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2009-10-02
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
Minor changes based on the final report from the referee; Movies are available from the first author
Scientific paper
Previous observations have not been able to exclude the possibility that high temperature active region loops are actually composed of many small scale threads that are in various stages of heating and cooling and only appear to be in equilibrium. With new observations from the EUV Imaging Spectrometer (EIS) and X-ray Telescope (XRT) on \textit{Hinode} we have the ability to investigate the properties of high temperature coronal plasma in extraordinary detail. We examine the emission in the core of an active region and find three independent lines of evidence for steady heating. We find that the emission observed in XRT is generally steady for hours, with a fluctuation level of approximately 15% in an individual pixel. Short-lived impulsive heating events are observed, but they appear to be unrelated to the steady emission that dominates the active region. Furthermore, we find no evidence for warm emission that is spatially correlated with the hot emission, as would be expected if the high temperature loops are the result of impulsive heating. Finally, we also find that intensities in the "moss", the footpoints of high temperature loops, are consistent with steady heating models provided that we account for the local expansion of the loop from the base of the transition region to the corona. In combination, these results provide strong evidence that the heating in the core of an active region is effectively steady, that is, the time between heating events is short relative to the relevant radiative and conductive cooling times.
Brooks David H.
Warren Harry P.
Winebarger Amy R.
No associations
LandOfFree
Evidence for Steady Heating: Observations of an Active Region Core with Hinode and TRACE 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 Evidence for Steady Heating: Observations of an Active Region Core with Hinode and TRACE, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evidence for Steady Heating: Observations of an Active Region Core with Hinode and TRACE will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-26805