Thermal And Statistical Properties of X-ray Bright Points

Abstract

HINODE’s X‐ray Telescope (XRT) offers a unique combination of high spatial (≈2″) and thermal resolution, full‐Sun observations of the solar corona over a wide range of temperatures (5.8∼<log T∼<7.6). We use multi‐filter Hinode/XRT data to explore the thermal, statistical and spatial properties of X‐ray bright points (XBPs). We have developed an automated XBP finder to study BPs over two periods during November 2007 and May 2008. We detect somewhat fewer XBPs than SOHO EIT in 195 A but find comparable values to the 284 A band. This is likely due in some part to the somewhat stricter requirements on XBP shape and enhancement above local background that we have adopted. We find that most XBPs appear to be relatively cool on average (log T≈6.1), only slightly hotter than the average quiet Sun. There is a trend for larger XBPs to be hotter, with a sub‐class of XBPs which are hotter still at all sizes. We further investigate the spatial distribution of XBPs, in particular exploring whether the “overhot” XBPs ha...