The Multi-modal DEM of Coronal Streamers as Seen by SDO/AIA Tomography

VÁSQUEZ, ALBERTO M.; NUEVO, FEDERICO A.; FRAZIN, RICHARD A.; LANDI, ENRICO

San Francisco

Congreso; AGU Fall Meeting; 2013

American Geophysical Union

The Atmospheric Imaging Assembly (AIA) telescope on board the Solar Dynamics Observatory (SDO) provides coronal EUV imaging over a broader temperature sensitivity range compared to the previous generations of instruments (EUVI, EIT, and TRACE). Differential emission measure tomography (DEMT) of the solar corona (Frazin et al. 2009) is performed with images of the four AIA bands that are most sensitive to the temperature range that dominates the emission of the quiet Sun. The increased number of the selected filters of AIA (4-bands sensitive to 0.55-3.75 MK) versus those of EUVI (3-bands sensitive to 0.60-2.70 MK), provides a "4th eye" over a significantly expanded temperature range. This also allows exploration of new parameterizations for the local differential emission measure (LDEM), assumed to be normal in previous 3-band DEMT works. With the objective of measuring the temperature distribution of the global quiescent corona over this expanded temperature range, we study Carrington rotation (CR) 2099, one of the earliest and the most quiet CR covered by AIA. Our study reveals a multi-modal nature of the LDEM distribution of the global coronal plasma at the tomographic resolution level not detected by the previous DEMT efforts. The multi-modality is stronger for hotter regions (within the closed fields of streamer regions) and less important for cooler ones (coronal holes). Our results may prove to be a useful constrain for coronal heating models of the quiet corona.