Space VLBI observations of 3C 371

被引:10
作者
Gómez, JL
Marscher, AP
机构
[1] CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain
[2] Boston Univ, Dept Astron, Boston, MA 02215 USA
关键词
BL Lacertae objects : individual (3C 371); galaxies : active; galaxies : jets; radio continuum : galaxies; techniques : interferometric;
D O I
10.1086/308360
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the first space VLBI observations of 3C 371, carried out at a frequency of 4.8 GHz. The combination of the high resolution provided by the orbiting antenna Highly Advanced Laboratory for Communications and Astronomy (HALCA) and the high sensitivity of the VLBA allows imaging of the jet of 3C 371 with an angular resolution of approximately 0.26 mas, which for this relatively nearby source corresponds to similar to 0.4 h(-1) pc. Comparison between two epochs separated by 66 days reveals no apparent motions in the inner 7 mas jet structure above an upper limit of similar to 1.4 h(-1) c. This value, the absence of detectable counterjet emission from the presumably symmetric jet, plus the presence of an extended double-lobe structure are consistent with the knots in the jet being stationary features such as standing shocks. The jet intensity declines with the angular distance from the core as phi(-1.68). This is more gradual than that derived for 3C 120, phi(-1.86), for which there is evidence for strong interactions between the jet and ambient medium. This suggests that in 3C 371 there is a greater level of in situ acceleration of electrons and amplification of magnetic field. We interpret sharp bends in the jet at sites of off-center knots as further evidence for the interaction between the jet and external medium, which may also be responsible for the generation of standing recollimation shocks. These recollimation shocks may be responsible for the presumably stationary components. The radio properties of 3C 371 are intermediate between those of other radio galaxies with bright cores and those of BL Lacertae objects.
引用
收藏
页码:245 / 250
页数:6
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