THE ASSOCIATION OF FAINT RADIO-SOURCES WITH FLUCTUATIONS IN THE X-RAY-BACKGROUND

We have examined edited, flat-fielded images from two of the Einstein Deep Survey pointings for X-ray fluctuations down to the 2 sigma level . Deep VLA images at 20 cm were obtained for both fields, and a compar ison of the positions of radio sources brighter than 150 microjanskys with the X-ray fluctuations reveals 21 coincidences; only seven are ex pected for uncorrelated samples, yielding a chance occurrence probabil ity of 10(-5). In addition, we find that the correlation of X-ray sour ces with radio source positions has a higher amplitude than the autoco rrelation function for the sources alone; i.e., X-ray emitting objects are found preferentially in areas of high submillijansky radio source density. While our results are consistent with the notion that the ma jority of the 0.3-3.5 keV X-ray sources at a flux threshold of approxi mately 10(-14) ergs cm-2 s-1 are the active galactic nuclei seen at br ighter fluxes, they reveal a potentially new population of X-ray and r adio luminous galaxies which could contribute substantially to the cos mic X-ray background.