A SOHO/UVCS study of coronal outflows at the edge of an active region complex

• Published in: Astronomy and astrophysics (Berlin) 2012-09, Vol.545, p.1-1
• Main Authors: Zangrilli, L, Poletto, G
• Format: Article
• Language: English
• Subjects: Indexing in process
• ISSN: 0004-6361; 1432-0746

In the past, active regions (AR) have been suggested as a possible source of the slow solar wind. Their role as solar wind contributors has recently been supported by HINODE observations at low coronal levels. The authors purpose is to determine whether outflows at the edges of ARs can be detected in higher layers of the corona, supporting the low-corona evidence for the occurrence of wind streams from ARs. Data acquired by SOHO/UVCS on Jan 2, 1998, at altitudes ranging from 1.5 to 2.3 solar radii at mid latitudes, were used to infer the physical properties of an AR complex at the time of its limb passage. Outflow speeds were inferred: outflows, at speeds increasing with height, turn out to be confined within a narrow channel at the edge of closed loop systems within the AR. Their results support the assumption that ARs are sources of slow wind. To their knowledge these are the first direct measurements of AR flows in the intermediate corona.