Quasi-period outflows observed by the X-Ray Telescope onboard Hinode in the boundary of an active region

TL;DR

This study uses Hinode's X-Ray Telescope to observe quasi-periodic, intermittent outflows at active region boundaries, which could significantly contribute to the slow solar wind's mass loading.

Contribution

It provides the first detailed analysis of quasi-periodic outflows at active region boundaries, highlighting their potential role in solar wind dynamics.

Findings

Outflows occur with a period of 5-10 minutes.

Flow speeds can exceed 200 km/s.

Outflows are intermittent and quasi-periodic.

Abstract

Persistent outflows have recently been detected at boundaries of some active regions. Although these outflows are suggested to be possible sources of the slow solar wind, the nature of these outflows is poorly understood. Through an analysis of an image sequence obtained by the X-Ray Telescope onboard the Hinode spacecraft, we found that quasi-period outflows are present in the boundary of an active region. The flows are observed to occur intermittently, often with a period of 5-10 minutes. The projected flow speed can reach more than 200 km/s, while its distribution peaks around 50 km/s. This sporadic high-speed outflow may play an important role in the mass loading process of the slow solar wind. Our results may imply that the outflow of the slow solar wind in the boundary of the active region is intermittent and quasi-periodic in nature.