Simultaneous observations of coronal bright points in X-ray and radio wavelengths

We present a first explicit comparison of coronal bright points in soft X-ray and radio wavelengths, using the Soft X-ray Telescope aboard the Yohkoh spacecraft and the Very Large Array. About half of the 33 compact sources identified in a 20-cm full-disk map appear as X-ray bright points in the X-ray data. The other half apparently corresponds to unipolar regions with enhanced magnetic fields. Thus, the identification of radio bright points alone cannot reliably serve as a proxy for X-ray bright points. A preliminary analysis reveals that bright points commonly observed at 20 cm and in X-rays have temperatures of (1.4-2.9) x 10 exp 6 K and emission measures of (0.4-2.5) x 10 exp 45/cu cm. The observed brightness temperatures at 20 cm (1-2.5) x 10 exp 5 K can be explained in terms of optically thin free-free emission from a plasma with these parameters.