PSEUDOSTREAMERS AS THE SOURCE OF A SEPARATE CLASS OF SOLAR CORONAL MASS EJECTIONS

Journal Article · Fri Apr 10 04:00:00 EDT 2015 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/803/1/L12· OSTI ID:22518695

Using white-light and extreme-ultraviolet imaging observations, we confirm that pseudostreamers (streamers that separate coronal holes of the same polarity) give rise to a different type of coronal mass ejection (CME) from that associated with helmet streamers (defined as separating coronal holes of opposite polarity). Whereas helmet streamers are the source of the familiar bubble-shaped CMEs characterized by gradual acceleration and a three-part structure, pseudostreamers produce narrower, fanlike ejections with roughly constant speeds. These ejections, which are typically triggered by underlying filament eruptions or small, flaring active regions, are confined laterally and channeled outward by the like-polarity open flux that converges onto the pseudostreamer plasma sheet from both sides. In contrast, helmet streamer CMEs are centered on the relatively weak field around the heliospheric current sheet and thus undergo greater lateral expansion. Pseudostreamer ejections have a morphological resemblance to white-light jets from coronal holes; however, unlike the latter, they are not primarily driven by interchange reconnection, and tend to have larger widths (∼20°–30°), lower speeds (∼250–700 km s{sup −1}), and more complex internal structure.

• OSTI ID: 22518695
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 803; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
EXTREME ULTRAVIOLET RADIATION
FILAMENTS
HELIOSPHERE
JETS
MAGNETIC FIELDS
MASS
PLASMA SHEET
SOLAR CORONA
SUN
VELOCITY
VISIBLE RADIATION