摘要
应用５ＧＨｚＶＬＢＩ技术在历元１９９７.１２的观测结果，给出ＢＬ Ｌａｃ天体ＡＯ ０２３５＋１６４在毫角秒尺度上的最新图像．该致密天体的射电结构由一个亮核所支配，另外在东北和西南方向各存在一个相对较弱的子源，其中东北方向的子源要比西南方向的明显得多.模型拟合结果显示，该源的喷流位置角为６６.４°，该数值超过以往的任何一次观测结果．根据流量密度随时间的变化关系，我们发现ＡＯ０２３５＋１６４在波长６ｃｍ上可能存在两种周期性的变化，即１—２年的短周期性变化和３－５年的长周期性变化这两种周期性的变化可能是由于喷流的爆发和旋转两种效应共同作用的结果．
new high resolution (-2 milli--arcsec) VLBI hybrid map at a wavelength of 6cmof the BL Lacertae object AO 0235+164 has been produced. The map shows that theobject's radio structure is dominated by a strong, nearly unresolved core, with two weakercomponents one in the NE, one in the SW, the former much clearer than the latter. Theposition angle of the jet component is 66.4°，larger than in previous observations. From thetime variation of the flux density, we find that there are probably two periodic variations,a shorter periodic variation of 1-2 yr and a longer one of 3-5 yr. These two periodicitiescould be due to joint action of jet outbursts and jet rotation.
基金
国家自然科学基金
上海天文台青年实验室资助
