Kinematics of the parsec-scale radio jet in 3C 48

	Kinematics of the parsec-scale radio jet in 3C 48
	An, T.1 ; Hong, X. Y.1; Hardcastle, M. J.2,3; Worrall, D. M.3; Venturi, T.4; Pearson, T. J.5; Shen, Z. -Q.1; Zhao, W.1 ; Feng, W. X.6
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2010-02-11
卷号	402 期号:1 页码:87-104
关键词	galaxies: active galaxies: jets galaxies: kinematics and dynamics quasars: individual: 3C 48
英文摘要	We present results on the compact steep-spectrum quasar 3C 48 from observations with the Very Long Baseline Array (VLBA), the Multi-Element Radio Linked Interferometer Network (MERLIN) and the European Very long baseline interferometry (VLBI) Network (EVN) at multiple radio frequencies. In the 1.5-GHz VLBI images, the radio jet is characterized by a series of bright knots. The active nucleus is embedded in the southernmost VLBI component A, which is further resolved into two sub-components A1 and A2 at 4.8 and 8.3 GHz, respectively. A1 shows a flat spectrum and A2 shows a steep spectrum. The most strongly polarized VLBI components are located at component C similar to 0.25 arcsec north of the core, where the jet starts to bend to the north-east. The polarization angles at C show gradual changes across the jet width at all observed frequencies, indicative of a gradient in the emission-weighted intrinsic polarization angle across the jet and possibly a systematic gradient in the rotation measure; moreover, the percentage of polarization increases near the curvature at C, likely consistent with the presence of a local jet-interstellar-medium interaction and/or changing magnetic-field directions. The hot spot B shows a higher rotation measure, and has no detected proper motion. These facts provide some evidence for a stationary shock in the vicinity of B. Comparison of the present VLBI observations with those made 8.43 yr ago suggests a significant northward motion for A2 with an apparent transverse velocity beta(app) = 3.7 +/- 0.4c. The apparent superluminal motion suggests that the relativistic jet plasma moves at a velocity of greater than or similar to 0.96c if the jet is viewed at an inclination angle less than 20 degrees. A simple precessing jet model and a hydrodynamical isothermal jet model with helical-mode Kelvin-Helmholtz instabilities are used to fit the oscillatory jet trajectory of 3C 48 defined by the bright knots.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	COMPACT STEEP-SPECTRUM ; ACTIVE GALACTIC NUCLEI ; 3C-48 HOST GALAXY ; POLARIMETRIC OBSERVATIONS ; RELATIVISTIC JETS ; KILOPARSEC-SCALE ; FARADAY-ROTATION ; QUASAR 3C-48 ; X-RAY ; 5 GHZ
收录类别	SCI
语种	英语
WOS记录号	WOS:000274453500009
公开日期	2011-06-29
内容类型	期刊论文
源URL	[http://119.78.226.72//handle/331011/13429]
专题	上海天文台_VLBI研究室
作者单位	1.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 2.Univ Hertfordshire, Sch Phys Astron & Math, Hatfield AL10 9AB, Herts, England 3.Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England 4.Ist Radioastron, INAF, I-40129 Bologna, Italy 5.CALTECH, Pasadena, CA 91125 USA 6.Liaocheng Univ, Liaocheng 252059, Peoples R China
推荐引用方式 GB/T 7714	An, T.,Hong, X. Y.,Hardcastle, M. J.,et al. Kinematics of the parsec-scale radio jet in 3C 48[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2010,402(1):87-104.
APA	An, T..,Hong, X. Y..,Hardcastle, M. J..,Worrall, D. M..,Venturi, T..,...&Feng, W. X..(2010).Kinematics of the parsec-scale radio jet in 3C 48.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,402(1),87-104.
MLA	An, T.,et al."Kinematics of the parsec-scale radio jet in 3C 48".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 402.1(2010):87-104.