# Material supply and magnetic configuration of an active region filament

## TL;DR

This study uses high-resolution observations to analyze the magnetic and thermal structures of a newly-formed active region filament, revealing plasma injection, magnetic reconnection, and counter-streaming flows, which enhance understanding of filament dynamics.

## Contribution

It provides detailed observational evidence of plasma injection, magnetic reconnection, and flow patterns in an active region filament, highlighting the support mechanism as a sheared arcade without dips.

## Key findings

- Cool plasma is injected into the filament at 5-10 km/s.
- Magnetic reconnection is linked to plasma replenishment.
- Counter-streamings are caused by unidirectional flows, not oscillations.

## Abstract

It is important to study the fine structures of solar filaments with high-resolution observations since it can help us understand the magnetic and thermal structures of the filaments and their dynamics. In this paper, we study a newly-formed filament located inside the active region NOAA 11762, which was observed by the 1.6 m New Solar Telescope (NST) at Big Bear Solar Observatory (BBSO) from 16:40:19 UT to 17:07:58 UT on 2013 June 5. As revealed by the H$\alpha$ filtergrams, cool material is seen to be injected into the filament spine with a speed of 5--10 km s$^{-1}$. At the source of the injection, brightenings are identified in the chromosphere, which is accompanied by magnetic cancellation in the photosphere, implying the importance of magnetic reconnection in replenishing the filament with plasmas from the lower atmosphere. Counter-streamings are detected near one endpoint of the filament, with the plane-of-the-sky speed being 7--9 km s$^{-1}$ in the H$\alpha$ red-wing filtergrams and 9--25 km s$^{-1}$ in the blue-wing filtergrams. The observations are indicative of that this active region filament is supported by a sheared arcade without magnetic dips, and the counter-streamings are due to unidirectional flows with alternative directions, rather than due to the longitudinal oscillations of filament threads as in many other filaments.