An accelerated jet in DA193
An accelerated jet in DA193
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DOI：
10.1051/0004-6361:20011439
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发表时间：
2001-12
影响因子：
6.5
通讯作者：
Wei Wang;X. Hong;D. Jiang;T. Venturi;Yu-Peng Chen;T. An
中科院分区：
文献类型：
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作者：
Wei Wang;X. Hong;D. Jiang;T. Venturi;Yu-Peng Chen;T. An
We present four epoch images with milliarcsecond resolution, from VLBI (Very Long Baseline Interferometry) observations of the quasar DA193 (J0555+3948) at 5GHz. The model-fitting results show that the source is resolved with a core-jet structure. A proper motion of 0.105 +/-0.02 mas yr(-1) of the jet component was estimated, which corresponds to an apparent velocity of 4.5 +/-0.86 h(-1) c at its redshift of z = 2.365. Estimates of the Doppler factor and of the brightness temperature confirm that this source is considerably boosted towards the line of sight. The velocity is about 4 times larger than previous estimates, which may indicate (1) that the jet component is being accelerated, possibly due to a bending jet aligned close to the line of sight; or (2) that there are two different components ejected in two flares. The possibility that multiple ejection of short-lived components is taking place in the core region of DA193 is also presented. Throughout this paper, the values q(0) = 0.5, H-0 = 100 km s(-1) Mpc(-1) will be used.
