Spatial and temporal correlations of chromospheric fibrils and jets with the active region moss emission have been extensively studied since the beginning of this millennium, suggesting a coupling between the million-degree corona and the much cooler chromosphere, both along the perpendicular to the field lines. We continued to investigate the interaction between chromospheric fibrils and mossy active region plage under high spatial and temporal resolutions, using the unique coordinated observations made by Solar Orbiter, the new NSF’s Daniel K. Inouye Solar Telescope (DKIST), and other near-Earth observatories on 24 October 2022. We identify apparent motions of fibrils observed in the Hα, Hβ, and Ca II K images obtained by the Visible Broadband Imager (VBI) on DKIST. Observations from the Slit-Jaw Imager (SJI) of the Interface Region Imaging Spectrometer (IRIS) and High Resolution Imager (HRI) telescope of the Extreme Ultraviolet Imager (EUI) were used to search for potential counterparts of fibril dynamics in the transition region and corona of the mossy plage. We also examine the alignment between the chromospheric fibrils and extrapolated magnetic fields. This study paves the way for future investigations of chromospheric dynamics using coordinated observations between Solar Orbiter and DKIST with its full suite of first-light instruments. We also outline additional scientific questions that such coordinated campaigns may help address.
Recent experiments and simulations have revealed glassy features in the cytoplasm, living tissues as well as dense assemblies of self propelled colloids. This leads to a fundamental question: how do these active amorphous materials differ from passive glasses, created either by lowering temperature or by increasing density?
To address this, we investigate dense systems of self-propelled particles, with an emphasis on the limit of large persistence times. The system then evolves intermittently between mechanical equilibria where active forces balance interparticle interactions. We develop an efficient numerical strategy allowing us to resolve the statistical properties of elastic and plastic relaxation events caused by activity-driven fluctuations. We find a time evolution consisting of a succession of scale-free elastic events and broadly distributed plastic events, with both having properties that depend on the system size. Correlations between plastic events lead to emergent dynamic facilitation and heterogeneous relaxation dynamics. Our results show that the steady state dynamics of extremely persistent active systems is qualitatively similar to that of sheared amorphous solids, yet with some important differences. Time permitting, extensions to aging behaviour will be discussed.
