标题： 远红外偏振的类星体3C 279 显示英文标题

标题： Far-infrared polarisation of the quasar 3C 279

摘要： 我们展示了使用ISOPHOT在1996年和1997年两个时期获得的OVV类星体3C 279的第一个FIR偏振结果。 我们在波长为170微米处描述了其积分偏振特性，此时源在其能量分布中显示出最大值。 在1996年1月的伽马射线爆发后，于1996年7月测得的偏振度为23%，与射电喷流轴紧密对齐。 在1997年6月，偏振度下降至6.5%，对齐程度较差。 另一方面，两个时期的总170微米通量是相同的。 我们的测量结果为射电喷流中同步辐射的多波段特性及其时间演化提供了额外的约束：它们表明3C 279的FIR辐射是光学薄的，且其起源非常接近核心。 FIR偏振的变化而总FIR通量没有变化，可以用核心和第一个静止的VLBI射电结之间的磁场紊乱来解释。 显示英文摘要

摘要： We present the first FIR polarisation results of the OVV quasar 3C 279 obtained with ISOPHOT for two epochs in 1996 and 1997. We describe its integral polarisation properties at a wavelength of 170 micron where the source shows a maximum in its energy distribution. After a gamma-ray flare in January 1996, a polarisation of 23 % closely aligned with the radio jet axis was measured in July 1996. In June 1997, the polarisation degree had decreased to 6.5 % with a less good alignment. On the other hand, the total 170 micron flux is the same for both epochs. Our measurements provide additional constraints for the multi-wavelength properties of synchrotron emission in radio jets and the temporal evolution of these properties: they show that the FIR radiation of 3C 279 is optically thin and that its origin is very close to the core. The variability of the FIR polarisation without any change of the total FIR flux can be explained by a disordering of the magnetic field in between the core and the first stationary VLBI radio knot.