국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Thermal Properties of A Solar Coronal Cavity Observed with the X-Ray Telescope on Hinode
저자	Reeves, Katherine K.;; Gibson, Sarah E.;; Kucera, Theresa A.;; Hudson, Hugh S.;; Kano, Ryouhei
Keyword	CAVITIES;; CYLINDRICAL BODIES;; EMISSION;; HEATING;; LINE OF SIGHT;; POLAR REGIONS;; RING STRUCTURES;; SOLAR CORONA;; THERMAL EMISSION;; THERMODYNAMIC PROPERTIES;; VOIDS;; X RAY TELESCOPES
URL	http://hdl.handle.net/2060/20110023545
보고서번호	GSFC.JA.5490.2011
발행년도	2011
출처	NTRS (NASA Technical Report Server)
ABSTRACT	Coronal cavities are voids in coronal emission often observed above high latitude filament channels. Sometimes, these cavities have areas of bright X-ray emission in their centers. In this study, we use data from the X-ray Telescope (XRT) on the Hinode satellite to examine the thermal emission properties of a cavity observed during July 2008 that contains bright X-ray emission in its center. Using ratios of XRT filters, we find evidence for elevated temperatures in the cavity center. The area of elevated temperature evolves from a ring-shaped structure at the beginning of the observation, to an elongated structure two days later, finally appearing as a compact round source four days after the initial observation. We use a morphological model to fit the cavity emission, and find that a uniform structure running through the cavity does not fit the observations well. Instead, the observations are reproduced by modeling several short cylindrical cavity "cores" with different parameters on different days. These changing core parameters may be due to some observed activity heating different parts of the cavity core at different times. We find that core temperatures of 1.75 MK, 1.7 MK and 2.0 MK (for July 19, July 21 and July 23, respectively) in the model lead to structures that are consistent with the data, and that line-of-sight effects serve to lower the effective temperature derived from the filter ratio.