Work

Three-dimensional Coronal Slow Modes: Toward Three-dimensional Seismology

Year: 2009

Type: article

Abstract: On 2008 January 10, the twin Solar Terrestrial Relations Observatory A and B spacecraft conducted a high time cadence study of the solar corona with the Extreme-Ultraviolet Imager instruments with the aim of investigating coronal dynamics. Observations of the three-dimensional propagation of waves within active region coronal loops and a measurement of the true coronal slow mode speed are obtained. Intensity oscillations with a period of ≈12 minutes are observed to propagate outward from the base of a loop system, consistent with the slow magnetoacoustic mode. A novel analysis technique is applied to measure the wave phase velocity in the observations of the A and B spacecraft. These stereoscopic observations are used to infer the three-dimensional velocity vector of the wave propagation, with an inclination of 37° ± 6° to the local normal and a magnitude of 132 ± 9 and 132 ± 11 km s −1 , giving the first measurement of the true coronal longitudinal slow mode speed, and an inferred temperature of 0.84 ± 0.12 MK and 0.84 ± 0.15 MK.

Source: The Astrophysical Journal

DOI: 10.1088/0004-637x/697/2/1674

Authors: M. S. Marsh, R. W. Walsh, S. Plunkett

Institutions: University of Lancashire, United States Naval Research Laboratory

Language: English

Topic: Solar and Space Plasma Dynamics

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: National Aeronautics and Space Administration, Goddard Space Flight Center, Science and Technology Facilities Council, Office of Naval Research

Awards: G1804274821, Determining the fundamental nature of the solar atmosphere: applying Bayesian analysis methods to Hinode observations